A CLOSURE FOR CAPILLARY COLUMNS

FIELD OF THE INVENTION

[001] This invention provides devices and methods for protecting a capillary column. The devices comprise a tube and a closure or a sealer to protect a capillary end that is placed within the tube. Devices of the invention may be reusable or disposable.

BACKGROUND OF THE INVENTION

[002] Gas Chromatograph (GC) is an analytical instrument which allows the identification of volatile metabolites. Samples are vaporized, separated in a column and subsequently analyzed by a detector. Beside volatiles, biological samples often contain many non- volatile compounds: organic acids, amino acids, sugars, sugar alcohols, aromatic amines and fatty acids. Chemical derivatization procedure is needed in order to render them volatile. A procedure that is often used for such treatment is oximation that is followed by silylation.

[003] A gas chromatographic system is comprised of six major components: gas supply and flow controllers, injector, detector, oven, column, and a data recording system. In most cases, the injector, detector and oven are integral parts of the gas chromatograph; the column, gases and recording device are separate items and are often supplied by a different manufacturer. The GC column is connected to the injector from one side and to the transfer line from another side. These connections should be hermetic at both low and high temperatures in order to prevent column leak. Different kinds of ferrules are used for this purpose.

[004] There are two general types of the GC columns: capillary and packed. GC columns of the same type can be distinguished by their selectivity. The choice of the GC column depends on the physical and chemical properties of the analytes. For example, the Agilent DB-5 capillary column can be used for the analysis of volatile compounds and for the analysis of polar compounds after derivatization, whereas an Agilent DB-1 column shows good separation of waxes. It should be mentioned that despite the fact that the same type of column (e.g. DB-5) can be used for the analysis of both volatile and polar compounds, it is strongly advisable to have two dedicated columns for each type of analysis, because the derivatization agent, used for the analysis of polar compounds can interfere with the analysis of volatiles. Therefore, the column should be changed each time the analyst differs from one type of analysis to another. The column, while disconnected from the GC instrument, remains opened on both sides, with ferrules attached to it.

[005] The maintenance of the injector or of the detector parts of a GC system is another case in which the GC column is disconnected from the GC instrument. The column can be disconnected from both sides (when the column is changed), but in some situations it is more practical to disconnect the column from only one side. In this case, the column remains opened on one side only. For example, when cleaning the detector (e.g. cleaning of the ion source in the case of an MS detector) the column is disconnected only from the detector (transfer line) side while it is still connected to the GC instrument (injector) on the other side. This configuration causes insertion of air into the column through the disconnected, open end of the column. Oxygen, present in the air, oxidizes the inner surface of the column and this shortens the column life-time and reduces its performance.

[006] To minimize the penetration of air into the column, the users employ a regular septum as a stopper. The users simply insert the sharp pin of the column into the septum. Before re- connection of the column to the GC instrument, the septum is removed. As small parts of the septum remain inside the column and contaminate it, the edge of the column (several centimeters) should be cut prior to use. The ferrule is situated at specific distance from the edge of the column; therefore, the edge should be cut off together with the ferrule. After cutting, a new ferrule replaces the used one.

[007] There are three main disadvantages of directly stacking the column into the septum:

1. Cutting several centimeters from the column each time one disconnects it from the instrument shortens the length of the column. This results in: (i) shortening the column life-time, and (ii) requirement for re-evaluation of the column length (using the instrument software) in order to keep the retention time parameters constant.

2. Accurate cutting of the column is not a trivial process: the new column edge should be done perfectly and strictly perpendicular to the column, otherwise the peak shapes in the chromatogram will not be symmetric. This complicates the procedure of reconnecting the column.

3. A new ferrule should be placed instead of the old one each time the column is disconnected from the instrument.

SUMMARY OF THE INVENTION

[008] In one embodiment, this invention provides a device for protecting a GC capillary, said device comprising:

• a tube, wherein a first end of said tube is open and a second end of

said tube is closed; and

• a closure, wherein said closure comprises a flexible material and

wherein said closure comprises a hole; wherein said closure surrounds said tube and is movable along said tube.

[009] In one embodiment, the closure is movable along the tube to a position wherein a first portion of the closure is extending outward from the open end of the tube (Figure 4, 4-20a) and a second portion of the closure remains around the outer surface of the open end of the tube (Figure 4, 4-20b). In one embodiment the diameter of the hole is not constant. In one embodiment, the diameter of the hole in the first portion is smaller than the diameter of the hole in the second portion.

[0010] In one embodiment, this invention provides a method for protecting a capillary, said method comprising: a. inserting at least one end of a GC capillary into a device comprising:

• a tube, wherein a first end of said tube is open and a second end

of said tube is closed; and

• a closure, wherein said closure comprises a flexible material

and wherein said closure comprises a hole;

wherein said closure surrounds said tube and is movable along said tube; b. moving said closure along said tube to said open end of said tube such that

a portion of said closure surrounds said capillary and wherein said closure is in contact with a portion of the outer surface of said capillary and wherein said closure is in contact with said open end of said tube, such that said closure seals the region between the outer surface of said capillary and said open end of said tube. [0011] In one embodiment, the closure is movable along said tube to a position wherein a first portion of said closure is extending outward from the open end of said tube and a second portion of said closure remains around the outer surface of said open end of said tube. In one embodiment, the diameter of said hole is not constant. In one embodiment, the diameter of the hole in the first portion is smaller than the diameter of the hole in the second portion.

[0012] In one embodiment, this invention provides a method for protecting a GC capillary, the method comprising:

a. inserting at least one end of a GC capillary into a first end of a tube wherein said first end of said tube is open and a second end of said tube is closed; b. surrounding said capillary with a sealer, wherein said sealer is in contact with a portion of the outer surface of said capillary and with said open end of said tube, such that said sealer seals the region between the outer surface of said capillary and said open end of said tube.

[0013] In one embodiment, the sealer comprises silicone and/or natural rubber. In one embodiment, the sealer comprises Teflon, Parafilm, polyvinyl acetate, ethylene vinyl acetate, polyvinyl alcohol, polyvinyl chloride, polytetrafluoroethylene, siloxane or a combination thereof.

BRIEF DESCRIPTION OF THE DRAWINGS [0014] The subject matter regarded as the invention is particularly pointed out and distinctly claimed in the concluding portion of the specification. The invention, however, both as to organization and method of operation, together with objects, features, and advantages thereof, may best be understood by reference to the following detailed description when read with the accompanying drawings in which:

[0015] Fig. 1 illustrates an embodiment of a device and method of the invention. In figure la, a device comprising a closure mounted on a tube is shown. In figure lb, a capillary column is inserted into the tube, and the closure is moved to the open end of the tube and seals the open end of the tube around the capillary column.

[0016] Fig. 2 illustrates an embodiment of a cross section of a device of the invention. Di and D ₂ represent the inner and outer diameters respectively of a tube. D ₃ represent the outer diameter of a circular closure that surrounds said tube and is in contact with the outer diameter of said tube. The inner diameter of the closure fits the outer surface of the tube. Therefore, the inner diameter of the closure is the same or similar to the outer diameter of the tube. This diameter may be defined by D ₂ in the figure. Accordingly, the inner diameter of the closure can be defined by the outer diameter of the tube.

[0017] Fig. 3 illustrates an embodiment of a device and method of the invention. The tube 3-10 is surrounded by a closure 3-20. The end of a capillary 3-30 is inserted into the tube, and the closure 3-20, surrounds a portion of said capillary and is in contact with a portion of said capillary. [0018] Fig. 4 illustrates an embodiment of a device of the invention. The closure (4- 20a and 4-20b) is surrounding both the capillary (4-10) and the tube (4-30). Closure portion 4-20a surrounds the capillary and closure portion 4-20b surrounds the tube. In the first portion of the closure (4-20a), the dimensions of the hole in the closure fit at least parts of the outer surface of the capillary. In these regions, the diameter of the hole is smaller than the diameter of the hole surrounding the tube (4-20b). Figure 4 top highlights the portion of the closure around a portion of the capillary and figure 4 bottom highlights the portion of the closure around a portion of the tube.

[0019] It will be appreciated that for simplicity and clarity of illustration, elements shown in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity. Further, where considered appropriate, reference numerals may be repeated among the figures to indicate corresponding or analogous elements.

DETAILED DESCRIPTION OF THE PRESENT INVENTION

[0020] In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these specific details. In other instances, well-known methods, procedures, and components have not been described in detail so as not to obscure the present invention.

[0021] This invention provides, in one embodiment, a new, simple and cheap device for closing the GC column when it is disconnected from the instrument. The device consists of a tube combined with a closure made from an elastic material (e.g. figure 1).

In one embodiment, the tube comprises glass or inert transparent plastic.

[0022] In one embodiment, the tube is combined with a hollow closure or a hollow cap wherein said closure or cap comprises an elastic material (figure 1).

[0023] In one embodiment, following the disconnection from the GC, a capillary column is inserted to the tube, and the elastic closure or cap is moved towards the open end of the tube, thus closing the entrance to it. Before connecting the column to the GC, the closure is moved towards the middle of the tube, thus opening the entrance to it.

The ferule surrounding the capillary column remains untouched.

[0024] In one embodiment, when devices and methods of the invention are used, there is no need for cutting the GC column prior to reuse of the column in a GC run.

Therefore, devices and methods of this invention have several advantages as compared to what is currently performed by GC users. The advantages include but are not limited to:

• The length of the GC column remains constant, and there is no need to re-evaluate its length after re-connection.

• Column re-connection is fast and does not require special qualification of the analyst.

• No need to use a new and costly ferrule each time the column is disconnected from the GC.

[0025] Devices and methods of this invention are cost effective and easy to use. The use of devices and methods of the invention saves time and money in handling the GC- instrument and in column maintenance. Thus, devices and methods of this invention extend the life of GC columns and reduce routine expenses in the analytical lab. To date, no similar devices are available.

[0026] In one embodiment, this invention provides a device for protecting a GC capillary, said device comprising:

• a tube, wherein a first end of said tube is open and a second end of

said tube is closed; and

• a closure, wherein said closure comprises a flexible material and

wherein said closure comprises a hole;

wherein said closure surrounds said tube and is movable along said tube.

[0027] In one embodiment, this invention provides a method for protecting a capillary, said method comprising: a. inserting at least one end of a GC capillary into a device comprising:

• a tube, wherein a first end of said tube is open and a

second end of said tube is closed; and

• a closure, wherein said closure comprises a flexible

material and wherein said closure comprises a hole;

wherein said closure surrounds said tube and is movable along said tube; b. moving said closure along said tube to said open end of said tube such that a portion of said closure surrounds said capillary and wherein said closure is in contact with a portion of the outer surface of said capillary and wherein said closure is in contact with said open end of said tube, such that said closure seals the region between the outer surface of said capillary and said open end of said tube.

[0028] In one embodiment, this invention provides a method for protecting a GC capillary, said method comprising:

a. inserting at least one end of a GC capillary into a first end of a tube wherein said first end of said tube is open and a second end of said tube is closed; and b. surrounding said capillary with a sealer, wherein said sealer is in contact

with a portion of the outer surface of said capillary and with said open end of said tube, such that said sealer seals the region between the outer surface of said capillary and said open end of said tube.

[0029] In one embodiment, this invention is directed to device and method of use thereof for protecting a GC capillary column. The term "protecting" refers to covering, enclosing, surrounding, and/or containing portions of a GC capillary column. In one embodiment, an end of the GC capillary is protected. In one embodiment, an end of the

GC capillary comprises the length of the GC capillary that is closest to the end of the capillary. In one embodiment, the end of the capillary means the 0-10 cm long portion of the capillary that is located at each end of the capillary. In one embodiment, if a GC capillary is 30 meters long, the last few cm (or the last 1 cm) at each end of the capillary are referred to as the end of the capillary. In one embodiment, the end of the capillary comprises an opening of the capillary.

[0030] In one embodiment, the device and methods of use thereof comprises a tube and a closure or a sealer. In another embodiment, the tube is a glass capillary. In one embodiment, the tube is in the form of a cylinder. In one embodiment, the shape of the tube is a cylinder that is closed on one side and is open on the other side. In one embodiment, the tube protects the end of the GC capillary. In one embodiment, the tube protects the GC capillary from contaminants that are present in the ambient. In one embodiment, placing the end of a GC capillary within the tube, prevents or diminishes the accumulation of contaminants inside the capillary or at and around the capillary's opening. In one embodiment, a GC column is synonyms with a "capillary". In one embodiment, a GC column is a capillary column. In one embodiment, a GC column is in the form of a capillary. In one embodiment, the term 'capillary' may refer to other components described in embodiments of the present invention.

[0031] In one embodiment, the device and methods of use thereof comprises a tube and a closure or a sealer. In another embodiment, the tube is a glass capillary closure is any object comprising a hollow shape. In one embodiment, the closure is in the form of a disc. In one embodiment, "disc" and "disk" are synonyms. In one embodiment the

"largest" and "smallest" diameters of the outer surface of the closure are related to the shape of the closure. According to this aspect and in one embodiment, when the closure is a hollow disc, the largest dimension of the outer surface of the disc may refer to the diameter of the disc, and the smallest dimension of the outer surface of the disc may refer to the width (or height) of the disc. In another embodiment, when the closure is in the shape of a hollow cylinder, the length (or height) of the cylinder may has the largest dimension and the diameter of the cylinder has the smallest dimension of the outer surface of the closure. If the closure is in the form of a hollow rectangular 3D object, the largest and the smallest dimensions of the outer surface of the closure refers to the length, width or height of the closure.

[0032] In one embodiment, the inner diameter of the tube is represented in figure 2. Figure 2 illustrates the cross section of a tube that is covered by a closure. is the inner diameter of the tube. In one embodiment, the outer diameter of the tube is represented in figure 2. The outer diameter of the tube is D ₂ . In one embodiment, the closure is surrounding the tube. In one embodiment, the hole in the closure fits the outer diameter of the tube. In one embodiment, the diameter of the hole in the closure equals or is similar to the outer diameter of the tube when the tube is placed within the closure. In one embodiment, the outer diameter of the closure is represented in figure 2. In one embodiment, the outer diameter of the closure is D ₃ .

[0033] In one embodiment, the term "movable" means that the closure may change its location with respect to the tube length. In one embodiment, the term "movable" means that the closure can be pushed and/or pulled along the tube. In one embodiment, the term "movable" means that the closure can slide along the tube. In one embodiment, the closure is movable to the end of the tube, to a position where portions of the closure are present beyond the end of the tube. In one embodiment, part of the closure is positioned on the end portion of the tube and another part of the closure is hanging outward from the end of the tube. In one embodiment, such placement of the closure with respect to the tube is illustrated in figure 1 b. [0034] In one embodiment, the closure comprises a flexible material. In one embodiment, the closure may deform. In one embodiment, the hole in the closure may shrink or expand to fit any object that is inserted within the hole. In one embodiment, the closure comprises elastic material that causes the closure to deform to the desired shape.

Materials

[0035] In one embodiment, the device and method of use of this invention comprise a tube and a closure or a sealer. In one embodiment, the tube comprises Si0 ₂ . According to this aspect and in one embodiment, the tube comprises glass. In one embodiment, the tube comprises glass or borosilicate glass (Pyrex). In one embodiment, the tube comprises poly(methyl methacrylate) (PMMA). In one embodiment, the tube comprises plexiglass or perspex. In one embodiment, the tube comprises a transparent material. In one embodiment, the tube comprises a semi-transparent material. In another embodiment, the tube is not transparent. In one embodiment, the tube comprises metal or metal alloy. In one embodiment, the tube comprises copper, stainless steel, aluminum and/or brass. In one embodiment, the tube comprises a coating. In one embodiment, the coating comprises Au, Ag, Pd, Pt, Ti, Cr or combinations thereof. In one embodiment, the coating comprises a polymer. In one embodiment, the inner area of the tube is coated. In one embodiment, the outer area of the tube is coated. In one embodiment, both the inner and the outer areas of the tube are coated.

[0036] In one embodiment, the device and method of use of this invention comprise a tube and a closure. In one embodiment, the closure comprises a flexible material. In one embodiment, the closure comprises silicone. In one embodiment, the closure comprises natural rubber. In one embodiment, the flexible material comprises natural rubber and/or silicone. In one embodiment, the closure comprises a polymer. In one embodiment, the closure comprises an elastic material. In one embodiment, the closure comprises an elastomer. In one embodiment, the closure comprises an elastic material. In one embodiment, the flexible material comprises teflon, Parafilm or a combination thereof. In one embodiment, the closure comprises polyvinyl acetate, ethylene vinyl acetate, polyvinyl alcohol, polyvinyl chloride, polytetrafluoroethylene, siloxane or a combination thereof. In one embodiment, the closure comprises polydimethylsiloxane.

[0037] In one embodiment, the flexible material is an elastic material. In one embodiment, the elastic material is a very elastic material. In one embodiment, the flexible material may deform.

[0038] In one embodiment, the device and method of use of this invention comprise a tube and a sealer. In one embodiment, the sealer comprises silicone. In one embodiment, the sealer comprises natural rubber. In one embodiment, the sealer comprises a polymer. In one embodiment, the sealer comprises an elastic material. In one embodiment, the sealer comprises an elastomer. In one embodiment, the sealer comprises a flexible material. In one embodiment, the sealer comprises an elastic material. In one embodiment, the sealer comprises teflon, parafilm, polyvinyl acetate, ethylene vinyl acetate, polyvinyl alcohol, polyvinyl chloride, polytetrafluoroethylene, siloxane or a combination thereof. In another embodiment, the sealer comprises polydimethylsiloxane.

Dimensions and values [0039] In some embodiments, the device and method of use of this invention comprise a tube and a closure or a sealer. In one embodiment, the inner diameter of the tube ranges between 100 micrometer and 5 mm. In one embodiment, the inner diameter of the tube ranges between 1 mm and 5 mm. In one embodiment, the inner diameter of the tube ranges between 200 micrometer and 5 mm. In one embodiment, the inner diameter of the tube ranges between 200 micrometer and 500 micrometers. In one embodiment, the inner diameter of the tube ranges between 400 micrometers and 1 mm. In one embodiment, the inner diameter of the tube ranges between 300 micrometer and 800 micrometers. In one embodiment, the inner diameter of the tube is 800 micrometers. In one embodiment, the inner diameter of the tube is 500 micrometers. In one embodiment, the inner diameter of the tube ranges between 2 mm and 3 mm.

[0040] In one embodiment, the outer diameter of said tube ranges between 200 micrometer and

5 mm. In one embodiment, the outer diameter of the tube ranges between 150 micrometer and 5 mm. In one embodiment, the outer diameter of the tube ranges between 1 mm and 5 mm. In one embodiment, the outer diameter of the tube ranges between 200 micrometer and 5 mm. In one embodiment, the outer diameter of the tube ranges between 200 micrometer and 500 micrometers. In one embodiment, the outer diameter of the tube ranges between 400 micrometers and 1 mm. In one embodiment, the outer diameter of the tube ranges between 300 micrometer and 800 micrometers. In one embodiment, the outer diameter of the tube is 800 micrometers. In one embodiment, the outer diameter of the tube is 500 micrometers. In one embodiment, the outer diameter of the tube ranges between 2 mm and 3 mm.

[0041] In one embodiment, the length of the tube ranges between 1.0 cm and 10 cm. In one embodiment, the length of the tube ranges between 1.0 cm and 5 cm. In one embodiment, the length of the tube ranges between 1.0 cm and 2.5 cm. In one embodiment, the length of the tube ranges between 0.5 cm and 2 cm. In one embodiment, the length of the tube ranges between 2.0 cm and 8.0 cm. In one embodiment, the length of the tube is 7 cm. In one embodiment, the length of the tube is 5 cm. In one embodiment, the length of the tube is 10 cm.

[0042] In one embodiment, the shape of the closure is not circular. In one embodiment, the shape of the closure is cubic. In one embodiment, the shape of the closure does not conform to any of the basic 3D geometries, e.g. a cube or a circle. In order to define the size of non-circular geometries of closures in some embodiments, the size of the "largest dimension" is described.

According to this aspect and in one embodiment, the "largest dimension" in the case of a circular/cylindrical closure is the outer diameter of the closure, or the thickness (height) of the closure. In the case of a cubical or box-like closure, or any shape similar to a cubical closure, the

"largest dimension" refers to either the length or the height of the closure whichever is larger. In cases where the cross section of the closure is triangular, the "largest dimension" may refer to one side of the triangle or to the height (length) of the closure. In one embodiment, when the length (height) of the closure is smaller than the cross section of the closure (e.g. cross section perpendicular to the length of the tube as depicted for example in figure 2), the "largest dimension" refers to the largest dimension that may describe the cross section. In a case of a cylinder, this largest dimension is the diameter. In the case of a non-symmetrical cross section, the largest dimension is the dimension of the longest line that can be drawn from one side of the cross section to another side. In one embodiment, "largest dimension" refers to the longest line that can be drawn from any given point on the outer surface of the closure to any other given point on the outer surface of the closure. In one embodiment, the largest dimension of the closure ranges between 5.0 mm and 20 mm. In one embodiment, the largest dimension of the closure ranges between 1.0 mm and 5 mm. In one embodiment, the largest dimension of the closure ranges between 2 mm and 20 mm. In one embodiment, the largest dimension of the closure ranges between 3 mm and 7 mm. In one embodiment, the largest dimension of the closure ranges between 5.0 mm and 10 mm. In One embodiment, the largest dimension of the closure is 5.0 mm. In one embodiment, the largest dimension of the closure is 10 mm.

[0043] In one embodiment, the smallest dimension of the outer surface of the closure ranges between 5 mm and 20 mm. In one embodiment, the smallest dimension of the closure ranges between 1 mm and 5 mm. In one embodiment, the smallest dimension of the closure ranges between 2 mm and 20 mm. In one embodiment, the smallest dimension of the closure ranges between 3 mm and 7 mm. In one embodiment, the smallest dimension of the closure ranges between 5 mm and 10 mm. In one embodiment, the smallest dimension of the closure is 5 mm. In one embodiment, the smallest dimension of the closure is 10 mm. In one embodiment, largest and smallest dimensions of the closure refer to the outer surface of the closure and not to the hole in it.

[0044] In one embodiment, the closure comprises a hole. In one embodiment, the diameter of the hole in the closure ranges between 500 micrometers and 5 mm. In one embodiment, the diameter of the hole in the closure ranges between 100 micrometer and 5 mm. In one embodiment, the diameter of the hole in the closure ranges between 150 micrometer and 5 mm.

In one embodiment, the diameter of the hole in the closure ranges between 1 mm and 5 mm. In one embodiment, the diameter of the hole in the closure ranges between 200 micrometer and 5 mm. In one embodiment, the diameter of the hole in the closure ranges between 200 micrometer and 500 micrometers. In one embodiment, the diameter of the hole in the closure ranges between 400 micrometers and 1 mm. In one embodiment, the diameter of the hole in the closure ranges between 300 micrometer and 800 micrometers. In one embodiment, the diameter of the hole in the closure is 800 micrometers. In one embodiment, the diameter of the hole in the closure is 500 micrometers. In one embodiment, the diameter of the hole in the closure ranges between 2 mm and 3 mm.

[0045] In one embodiment, the diameter of the hole equals or is similar to the outer diameter of the tube when the tube is placed within the closure. In one embodiment, the shape and dimensions of the closure and/or of the hole in it may deform. In one embodiment, the diameter of the hole varies to fit the outer surface of any object that is placed within the hole. In one embodiment, the shape and dimensions of the closure and/or of the hole varies to fit the outer surface of the tube and/or of the GC capillary that is placed within the hole.

[0046] In one embodiment, the diameter of the hole is not constant. In one embodiment, the closure comprises two portions when the closure is placed around the tube and around the capillary end. In one embodiment, the closure at such position comprises a first portion that is surrounding the capillary and a second portion that surrounds the tube. In one embodiment, such configuration of the closure is depicted in figure 4. The first portion, Portion 4-20a, is the portion that surrounds the capillary. The second portion, portion 4-20b, is the portion that surrounds the tube. The vertical dashed line in the center of the figure represents the border line between the first and the second portions. In one embodiment, the diameter of the hole in at least parts of the first portion (Figure 4, 4-20a) of the closure is smaller than the diameter of the hole in the second portion (Figure 4, 4-20b) of the closure. In one embodiment, the diameter of the hole in the region surrounding a portion of the GC column (i.e. the capillary, 4-20a) is smaller than the diameter of the hole in the region surrounding the tube (4-20b). In one embodiment, the diameter of the hole surrounding a portion of the GC column fits the outer diameter of the GC column. The diameter of the hole surrounding the tube fits the outer diameter of the tube. In one embodiment, the term "fits" indicate that there is no open space between the closure and the portion of the GC column that is surrounded by the closure and that there is no open space between the closure and the outer surface of the tube in the region where the closure surrounds the tube. In one embodiment, the closure thus prevents materials such as contaminants to be transferred from the area outside the tube to the area inside the tube, when the closure closes the open end of the tube around a portion of the GC column.

[0047] In one embodiment, the shape of the closure may deform.

[0048] In one embodiment, the diameter of the hole in the closure is not constant. In one embodiment, the diameter of the hole in the closure is smallest around a portion of the capillary, is largest around the tube, and it acquires intermediate diameter values in between the largest and the smallest diameters. In one embodiment, in the first portion, around the capillary, the hole in the closure may posses a gradient in diameter such that the diameter of the hole along the capillary is in the form of a cone, The largest diameter of the hole according to this aspect is close to the tube end, and the smallest diameter is at the end of the closure farthest from the tube, on top of the capillary.

Shape and Geometries

[0049] In some embodiments, the device and method of use of this invention comprise a tube and a closure or a sealer. In one embodiment, the tube is cylindrical. In one embodiment, the tube is shaped as a cuboid, a rectangular box/hexahedron. In one embodiment the tube is an elongated hollow structure comprising a square or a rectangular cross section, a circular or elliptical cross section, or a triangular or hexagonal or octahedral cross section. In another embodiment, the tube may comprise any elongated shape that is closed on one end and is open on the other end.

[0050] In one embodiment, the closure is in the form of a hollow disc, a hollow tube, a hollow cube or a hollow hexahedron, In one embodiment, the closure comprises any hollow shape. In one embodiment, the closure does not have a defined shape. In one embodiment, the shape of the closure may deform.

[0051] In one embodiment, the sealer is in the form of a tape. In one embodiment, the sealer is an adhesive tape. In one embodiment, the sealer is deformable. In one embodiment, the sealer is a deformable solid. According to this aspect and in one embodiment, the deformable solid may acquire any desired shape. In one embodiment, the deformable solid may be molded manually. In one embodiment, the sealer is in the form of a clamp. In one embodiment, the shape of the sealer may deform.

Devices of the invention

[0052] In some embodiments, the device and method of use of this invention comprise a tube and a closure or a sealer. In one embodiment, the device further comprises attachments to the GC column. In one embodiment, the attachments secure the device to the GC column. In one embodiment, the attachments hold the device and the GC column in a stable configuration. In one embodiment, the attachments prevent or diminish the possibility that the GC column will become disconnected from the tube and/or from the closure. In one embodiment, the attachments prevent or diminish the possibility that the GC column will be pulled out from the tube to the point where the opening of the GC column resides within the closure. In one embodiment, this will prevent or diminish the possibility that the GC column will get contaminated by materials from which the closure is made.

[0053] In one embodiment, the device is operated manually. In one embodiment, the closure is movable manually. According to this aspect and in one embodiment, the end of the GC capillary is manually inserted into the tube, and the closure is manually moved from its position on the tube toward the open end of the tube, and onto the capillary, such that the closure covers both the portion of the capillary at the open end of the tube and the open end of the tube. This position of the closure prevents air and/or contaminants or any materials present in the air from entering the tube while the capillary's end is within the tube.

[0054] In one embodiment, portions of the outer surface of the tube are coated with a soft material. According to this aspect, and in one embodiment, the soft material is applied to the outer surface of the tube (or to portions of it) in order to form an area on the tube for manual handling of the tube by the user. In one embodiment, applying soft material to the outside surface of the tube enables the user to comfortably hold the tube. In one embodiment, the user may hold the tube with one hand at the area where the soft material is applied and move the closure with his other hand. In one embodiment, applying soft material to outer areas of the tube protects the tube from breaking. In one embodiment, the soft material is plastic, Parafilm, teflon.

In one embodiment, the soft material is applied using a tape. In one embodiment, the soft material is coated onto the tube from a liquid polymer or from a polymeric solution. In one embodiment, the coating is in the form of a glue or a sticker. In one embodiment, the tube is dipped in a solution or in a liquid followed by removing the tube from the solution or the liquid.

According to this aspect, and in on embodiment, soft liquid material may stick or adhere to the tube and may solidify/dry around the tube after removal of the tube from the liquid/solution. Drying/solidifying of the soft material on the tube may be done at room temperature, at elevated temperatures and/or through the use of radiation (e.g. UV/visible light). In one embodiment, the soft material protects the tube. In one embodiment, the soft material reduces the risk of breaking the tube. In one embodiment, the soft material helps the user to hold the tube while moving the closure, without the risk of breaking the tube. In one embodiment, the soft material that coats portions of the tube provides a comfortable area for holding the tube. In one embodiment, the soft material is applied to the tube by wrapping and/or taping it to the tube. In one embodiment, the soft material is applied to the tube by dipping the tube in a liquid polymer and hardening of the polymer. In one embodiment, the soft material is applied to portions of the outer surface of the tube by any coating method that is known to a person skilled in the art.

[0055J In one embodiment, the closure comprises a flexible material. In one embodiment, the flexible material comprises a material such as silicone. In one embodiment, the flexibility of the material is needed for the operation of the device. In one embodiment, the flexibility of the material enables the closure to be moved along the outer surface of the tube. In one embodiment, the closure comprises a flexible material so that a hole can be drilled/punctured, molded in it. In one embodiment, the closure comprises a flexible material such that the hole in it may conform to any object that is placed within the hole. In one embodiment, the closure comprises a flexible material such that when an object of certain dimensions is placed within the hole in the closure, the closure will match the object, and the hole will fit the dimensions of the object. This flexibility enables the closure to seal the area around any object that is placed within the closure. For example, when portions of the closure are moved toward the open end of the tube, the hole in the closure shrinks to fit the outer diameter of the capillary which is smaller than the outer diameter of the tube in one embodiment. When portions of the closure are moved back from the capillary location to the tube, the hole in the closure expands to fit the outer diameter of the tube which is larger than the outer diameter of the capillary in one embodiment.

[0056] In one embodiment, the closure is movable manually. In one embodiment, the closure is movable automatically. In one embodiment, the insertion of the capillary into the tube induces an automatic movement of the closure toward the end of the tube and onto the capillary. In one embodiment, the pulling of the capillary out of the tube induces an automatic movement of the closure fi-om the end of the tube toward the central region of the outer surface of the tube. In one embodiment, other automated mechanisms can be applied for the movement of the closure and/or for the movement of the capillary/tube.

[0057] In one embodiment, the diameter of the hole varies to fit the outer surface of any object that is placed within said hole. In one embodiment, this feature enables the closure to seal the area between portions of the outer surface of the capillary and the open end of the tube. The closure may thus be in contact with both the outer surface of portions of the capillary and with the region at the open end of the tube. Such construction prevents air or materials that are present in the air to enter the tube while the end of the capillary resides within the tube. Such configuration of the closure prevents air/contaminants to reach the inner part of the capillary.

[0058] In one embodiment, the closure is movable along the tube to a position wherein a first portion of said closure is extending outward from the open end of said tube and a second portion of said closure remains around the outer surface of said open end of said tube. In one embodiment, the first portion that is extending outward from the open end of the tube, surrounds the portion of the capillary that is located near the open end of the tube. In this portion of the closure, the hole in the closure get smaller until the inner surface of the closure is in contact with the outer surface of the corresponding portion of the capillary. The second portion of the closure that remains surrounding the tube, retains the original dimensions of the hole in the closure. The closure thus surrounds both the capillary and the tube.

[0059] In one embodiment, devices of this invention are made by providing a tube, wherein the first end of the tube is open and the second end of the tube is closed; and providing a closure, wherein the closure comprises a flexible material and wherein the closure comprises a hole. The tube is then inserted into the closure through the hole, such that the closure surrounds the tube and is movable along the tube.

Methods of use

[0060] In one embodiment, prior to use, the tube may be cleaned by an inert gas. In one embodiment, the inert gas is Ar or N ₂ . In one embodiment, the inert gas is introduced to the tube in order to remove possible contaminants present in the tube prior to use in methods of the invention. In one embodiment, when both ends of a capillary are protected by one or more devices of the invention, the tube or tubes may be evacuated such that the protected capillary is kept under vacuum. According to this aspect and in one embodiment, appropriate openings/connections are constructed on the tube for connection to a vacuum pump.

[0061] In one embodiment, methods of the present invention prevent contact between the opening of the GC capillary column and the closure or the sealer. In one embodiment, no contact between the capillary column opening and the closure or the sealer prevents contamination of the capillary by the material or materials from which the closure or sealer are made. In one embodiment, this is achieved by first inserting the capillary into the tube such that the opening of the capillary is protected by the tube, and only then the closure/sealer is applied to the area of the open end of the tube where it surrounds a portion of the capillary and seals the open end of the tube around that portion of the capillary. [0062] In one embodiment, closures and devices of this invention may be used to protect capillary columns, i.e. the end portions of the capillary columns. For example, columns like

Agilent's DB-5 and Agilent's DB-1 columns can be protected by devices of this invention. The

Agilent DB-5 capillary column is a column comprising a stationary phase composition which contains 5% phenyl arylene polymer which is equivalent to a 5%-phenyl-methylpolysiloxane and 95% dimethylpolysiloxane. Other similar columns from different companies or any custom made capillaries can be used with closures and devices of this invention. In one embodiment, an

Agilent DB-5 column can be used for the analysis of volatile compounds and for the analysis of polar compounds after derivatization. In one embodiment, when not in use, or between subsequent uses, or during GC maintenance, the column is protected by devices of this invention. In one embodiment, an Agilent DB-1 (a column comprising a stationary phase composition which contains 100% dimethylpolysiloxane) shows good separation of waxes. Any of these columns and any other column can be protected by devices of this invention.

[0063] In the claims articles such as "a,", "an" and "the" mean one or more than one unless indicated to the contrary or otherwise evident from the context. Claims or descriptions that include "or" or "and/or" between members of a group are considered satisfied if one, more than one, or all of the group members are present in, employed in, or otherwise relevant to a given product or process unless indicated to the contrary or otherwise evident from the context. The invention includes embodiments in which exactly one member of the group is present in, employed in, or otherwise relevant to a given product or process. The invention also includes embodiments in which more than one, or all of the group members are present in, employed in, or otherwise relevant to a given product or process. Furthermore, it is to be understood that the invention provides, in various embodiments, all variations, combinations, and permutations in which one or more limitations, elements, clauses, descriptive terms, etc., from one or more of the listed claims is introduced into another claim dependent on the same base claim unless otherwise indicated or unless it would be evident to one of ordinary skill in the art that a contradiction or inconsistency would arise. Where elements are presented as lists, e.g. in Markush group format or the like, it is to be understood that each subgroup of the elements is also disclosed, and any element(s) can be removed from the group. It should be understood that, in general, where the invention, or aspects of the invention, is/are referred to as comprising particular elements, features, etc., certain embodiments of the invention or aspects of the invention consist, or consist essentially of, such elements, features, etc. For purposes of simplicity those embodiments have not in every case been specifically set forth in haec verba herein. Certain claims are presented in dependent form for the sake of convenience, but Applicant reserves the right to rewrite any dependent claim in independent format to include the elements or limitations of the independent claim and any other claim(s) on which such claim depends, and such rewritten claim is to be considered equivalent in all respects to the dependent claim in whatever form it is in (either amended or unamended) prior to being rewritten in independent format.

[0064] In one embodiment, the diameter of said hole in said first portion (4-20a) is smaller than the diameter of said hole in said second portion (4-20b). In one embodiment, the end of the capillary is not in contact with the inner portion of the closed end of the tube. In one embodiment, the length of the portion of the capillary that is placed within the tube ranges between 1 cm and 10 cm.

[0065] In one embodiment, the end of the capillary is in contact with the inner portion of the closed end of the tube. [0066] In one embodiment, the end of the capillary is not in contact with the inner portion of the closed end of the tube. In one embodiment, the end of the capillary is in contact with the inner portion of the closed end of the tube.

[0067] In one embodiment, the length of the portion of the capillary that is placed within the tube ranges between 1 cm and 10 cm.

[0068] The following examples are presented in order to more fully illustrate the preferred embodiments of the invention. They should in no way be construed, however, as limiting the broad scope of the invention.

EXAMPLES EXAMPLE 1

Protecting a GC capillary (Ϊ)

[0069] A glass capillary tube was coated with a soft tape on the portion that is close to the closed end of the tube. The tube length was 7 cm. An elastic hollow closure was fitted to portion of the outer surface of the tube, around the middle of the tube. The end of a GC capillary column was inserted through the open end of the tube into the tube, such that about 3-6 cm of the length of the capillary from its end were contained in the tube. The closure was manually moved along the length of the tube toward the open end of the tube. The closure was moved until it reached the open end of the tube. The closure was moved further so that a portion of the closure was extending beyond the open end of the tube. This portion of the closure surrounded portion of the GC capillary column right before the entrance of the tube. The closure in the region around the capillary column deformed such that the dimensions of the hole in the closure were reduced to fit the outer diameter of the GC capillary column. The dimensions of the hole in the closure in the portion of the closure that remained on the tube had not changed. At this stage, the area between the capillary outer surface and the open end of the tube was sealed at and around the open end of the tube. At this stage, the closure was in contact with both the tube and the GC capillary column.

[0070] When the GC capillary column was ready to be used or reused, the closure was moved back to its position along the tube, away from the open end of the tube. The GC capillary column was then pulled out from the tube and was ready to be used or reused. Throughout the process described herein above, the very end of the capillary (the capillary opening) was not in contact with the closure, so that it could not be contaminated by the materials from which the closure was made.

EXAMPLE 2

Protecting a GC capillary (ii)

[0071] The end of a GC capillary column was inserted into a glass capillary tube. The tube length was 7 cm. The end of a GC capillary column was inserted through the open end of the tube into the tube, such that about 3-6 cm of the length of the capillary from its end were contained in the tube. A sealer in the form of a tape was applied to the open end of the tube, such that the sealer surrounded both the GC capillary column and the open end of the tube. At this stage a portion of the sealer was extending beyond the open end of the tube. This portion of the sealer surrounded portion of the GC capillary column right before the entrance of the tube. At this stage, the area between the capillary outer surface and the open end of the tube was sealed at and around the open end of the tube. At this stage, the sealer was in contact with both the tube and the GC capillary column.

[0072] When the GC capillary column was ready to be used or reused, the sealer was removed. The GC capillary column was then pulled out from the tube and was ready to be used or reused. Throughout the process described herein above, the very end of the capillary (the capillary opening) was not in contact with the sealer, so that it could not be contaminated by the materials from which the sealer was made.

[0073] While certain features of the invention have been illustrated and described herein, many modifications, substitutions, changes, and equivalents will now occur to those of ordinary skill in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.