JP3045708U - Sampling needle for autosampler - Google Patents

Abstract

(57) [Summary] [Problem] Sampling that has the strength required to make a hole in a vial cap, has the same surface inertness as a needle made of polyetheretherketone, and does not elute components that hinder measurement. Get the needle. SOLUTION: A polyimide tube 3 is adhered to an inner surface of a stainless steel needle 2 and gold plating is applied to an outer surface of the needle 2.

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 The present invention relates to a sampling needle used in an ion chromatograph and an autosampler for analyzing a biological sample.

[0002]

[Prior art]

 As for the sampling needle used for ion chromatography and autosampler for biological sample analysis, development of a needle satisfying the following three points has been required.

First, the first point is that it has the same strength as a stainless steel needle. This is to make a hole in the vial cap (Teflon liner), and the strength of a polyether ether ketone needle (hereinafter referred to as “PEEK needle”) with high surface inertness (inert) is weak. Cannot be used with vial caps on.

[0004] The second point is that it has surface inertness (inert) like a PEEK needle. As a result, the sample is not adsorbed on the inner surface of the needle at the time of sampling, and the sample can be quickly replaced. It should be noted that replacement of the stainless steel needle on the inner wall surface is poor, and an extra sample is required for washing the needle together.

On the other hand, components do not adsorb or remain outside the needle at the time of sampling. In the case of stainless steel needles, selective retention of components is recognized under certain conditions, which is a source of contamination.

The third point is that there is no elution of components that interfere with the measurement.

[0007]

[Problems to be solved by the invention]

 Conventionally, there is no needle that satisfies the above three points, and as a result of extensive research, the present inventors have used a stainless needle and adhered a polyimide tube to the inner surface of the needle and plated the outer surface to satisfy the above three points. They learned that a needle could be obtained and completed the present invention.

[0008]

[Means for Solving the Problems]

 The gist of the present invention resides in a sampling needle for an autosampler, which is characterized in that a polyimide tube is adhered to the inner surface of a stainless steel needle and plated outside the needle. Preferably, the plating is gold plating.

[0009]

[Embodiment of the invention]

 Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a partially enlarged sectional view of a sampling needle according to the present invention.

In FIG. 1, reference numeral 1 denotes a sampling needle, and reference numeral 2 denotes a stainless steel needle that forms a main body of the sampling needle 1. Reference numeral 3 denotes a polyimide tube adhered to the inner surface of the stainless steel needle 2. Reference numeral 4 denotes gold plating applied to the outside of the stainless steel needle 2.

Thus, the sampling needle of the present embodiment has sufficient strength to make a hole in the vial cap, and has a small amount of sample adsorbed on the inner surface of the needle at the time of sampling. No sample adsorption or residue. Furthermore, there is no elution of components that interfere with the measurement.

Next, in order to clarify the above effects, test examples of the present invention will be described. In addition, the results of the replacement ratio test performed on each material to confirm the inertness of the inner surface of the needle were as follows. PEEK ≒ Polyimide≫Stainless Steel ≒ Titanium

In the test, a sample loop as shown in FIG. 2 was prepared, and a sample loop containing a needle to be evaluated as shown in 6 in FIG. Is to evaluate the degree of Sulfate ions and phosphate ions, which are generally measured by the ion chromatography method, adsorb to the surface of stainless steel and titanium under weak acidity, but do not adsorb to the surface of a resin such as PEEK which is inactive. The volume of the loop after inserting the needle is about 150 μl.

The needles to be evaluated include PEEK needles, stainless steel needles, processing needles A (coating with an inner polyimide tube + outer gold plating), processing needles B (coating with an inner polyimide tube), and titanium needles. Type.

[0015] The injection was performed as follows. After passing 0.6 ml of a 0.01 mol / l hydrochloric acid-acidic anion standard solution through the loop, a 0.001 mol / 1 hydrochloric acid solution was added. Injection after replacing with 6 ml, and replacement after replacing the inside of the loop with 0.6 ml of 0.001 mol / 1 hydrochloric acid solution.

The components of the anion standard solution are 0.5 ppm fluoride ion, 1 ppm chloride ion, 1 ppm nitrite ion, 1 ppm bromide ion, 1 ppm nitrate ion, 1.5 ppm phosphate ion, 1.5 ppm sulfate ion. It is.

The results are as shown in the chromatographs of FIGS. FIGS. 3 to 7 show the case of the above-described injection, and FIGS. 8 to 12 show the case of the above-described injection. 3 and 8 are the needles, FIGS. 4 and 9 are the needles, FIGS. 5 and 10 are the needles, FIGS. 6 and 11 are the needles, and FIGS. The results for the needle described above are shown. FIG. 8 shows blank data having the meaning of confirming that the sulfate ions detected in FIG. 3 were not eluted from the needle by the 0.001 mol / l hydrochloric acid solution. FIG. 9 shows blank data which has the meaning of confirming that the sulfate ions detected in FIG. 4 are not eluted from the needle by the 0.001 mol / l hydrochloric acid solution. FIG. 10 shows blank data having a meaning of confirming that the sulfate ions detected in FIG. 5 are not eluted from the needle with a 0.001 mol / l hydrochloric acid solution. FIG. 11 shows blank data having a meaning of confirming that the sulfate ions detected in FIG. 6 were not eluted from the needle with a 0.001 mol / l hydrochloric acid solution. FIG. 12 shows blank data having the meaning of confirming that the sulfate ion detected in FIG. 7 is not the elution from the needle by the 0.001 mol / l hydrochloric acid solution.

A comparison of the chromatographs in FIGS. 3 to 7 confirms that the PEEK needle has less sulfate ion residue and has a higher inertness than the stainless needle and titanium needle. In addition, it was confirmed that the processed needle A (coating with an inner polyimide tube + outer gold plating) according to the present invention has a small amount of sulfate ions as high as the PEEK needle, and has high inertness. In the case of the processing needle B (coated with a tube of the inner surface polyimide), a residue approximately in the middle between the PEEK needle and the stainless needle was observed. This is thought to be because the outer surface of the needle remained the surface of stainless steel.

In addition, the needle according to the present invention was subjected to an elution component test in addition to the above-described adsorption test on the needle surface. Methanol extraction test 5 ml of methanol, ultrasonic extraction for 10 to 30 minutes → No detection of 254 nm absorbance component. Anion component elution test Alkaline extract (2.8 mM Na ₂ CO ₃ -2.2 mM NaHCO ₃ ) 10 ml, ultrasonic extraction 10 minutes → No anion component detected (fluoride ion, chloride ion, nitrite ion, bromide) Ion, nitrate ion, phosphate ion, each 1 μg / 10 ml or less).

[0020]

[Effect of the invention]

 Since the present invention is configured as described above, it has the strength required to make a hole in the vial cap and has the same surface inertness (inert) as the PEEK needle. In addition, components that interfere with the measurement are not eluted. Therefore, it is extremely effective for the analysis of biological samples handling small amounts of samples by ion chromatography analysis. (Note) In the detailed description of the invention, Teflon is a registered trademark.

[Brief description of the drawings]

FIG. 1 is a partially enlarged sectional view of a sampling needle according to the present invention.

FIG. 2 is an explanatory diagram of a sample loop used for an inertness test.

FIG. 3 is a chromatogram showing the inertness of a PEEK needle by an inertness test.

FIG. 4 is a chromatograph showing the inertness of a stainless needle by an inertness test.

FIG. 5 is a chromatogram showing the inertness of the needle according to the present invention by an inertness test.

FIG. 6 is a chromatogram showing the inertness of a needle obtained by coating a stainless steel needle with a polyimide tube on the inner surface thereof by an inertity test.

FIG. 7 is a chromatogram showing the inertness of a titanium needle by an inertness test.

FIG. 8 shows that the sulfate ion detected in FIG.
It is blank data which has the meaning of confirming that it is not elution from a needle by 1 / l hydrochloric acid solution.

FIG. 9 shows that the sulfate ion detected in FIG.
It is blank data which has the meaning of confirming that it is not elution from a needle by 1 / l hydrochloric acid solution.

FIG. 10 shows that the sulfate ion detected in FIG.
It is blank data which has the meaning of confirming that it is not elution from a needle by an ol / l hydrochloric acid solution.

FIG. 11 shows that the sulfate ion detected in FIG.
It is blank data which has the meaning of confirming that it is not elution from a needle by an ol / l hydrochloric acid solution.

FIG. 12 shows that the sulfate ion detected in FIG.
It is blank data which has the meaning of confirming that it is not elution from a needle by an ol / l hydrochloric acid solution.

[Explanation of symbols]

 1 Sampling needle 2 Stainless steel needle 3 Polyimide tube 4 Gold plating

Claims (2)

[Utility model registration claims] 1. A sampling needle for an autosampler, characterized in that a polyimide tube is adhered to the inner surface of a stainless steel needle and plated outside the needle. 2. The sampling needle for an autosampler according to claim 1, wherein the plating is gold plating.