JP7069587B2 - How to clean analytical equipment - Google Patents

Description

The present invention relates to a method for cleaning an analytical instrument.

Analytical instruments can be contaminated by the reagents used and the samples to be measured, often affecting the measurement results. In particular, it is known that contamination is likely to occur in equipment that targets crude samples containing various substances such as blood samples, and cleaning agent compositions and cleaning to maintain the analytical equipment in a normal state. Techniques related to the method are needed.

When cleaning an analytical instrument, a method of removing contamination by using a strong acid solution, a strong alkaline solution, an organic solvent, or the like alone or in combination is known. For example, an aqueous solution of nitric acid, an aqueous solution of sodium hydroxide, acetone, or the like can be used in cleaning a liquid chromatograph. However, when a strong acid solution, a strong alkaline solution, an organic solvent, etc. are used as a cleaning agent, care must be taken in handling them due to their harmfulness and danger to the human body and corrosiveness to analytical instruments. There is a need for a cleaning method that can remove contamination. As such a technique, for example, a cleaning method for a liquid chromatograph (see Patent Document 1) and a cleaning method for a blood analyzer (see Patent Document 2) have been proposed, but the cleaning effect may be insufficient. There was a need for a more effective cleaning method.

Japanese Unexamined Patent Publication No. 10-318999 Japanese Unexamined Patent Publication No. 2017-057420

An object of the present invention is to provide a method for cleaning an analytical instrument.

As a result of diligent research on the above-mentioned problems, the present inventor has completed the present invention. That is, the present invention is as follows.
(1) A method for cleaning an analytical instrument, which comprises supplying a cleaning agent containing at least one kind of protease to the analytical instrument and then supplying the cleaning agent containing at least one kind of surfactant to the analytical instrument. ..
(2) The method according to (1), wherein both the detergent containing the protease and the detergent containing the surfactant have a pH of 3 or more and 11 or less.
(3) The method according to (1) or (2), which does not include a step of supplying a cleaning composition containing an organic solvent to an analytical instrument.
(4) The method according to any one of (1) to (3), wherein the analytical instrument is a liquid chromatograph.

The present invention will be described in detail below.

The present invention is characterized in that a cleaning agent containing at least one type of protease is supplied to the analytical instrument, and then a cleaning agent containing at least one type of surfactant is supplied to the analytical instrument. Regarding the method. In the present invention, "supplying the cleaning agent to the analytical instrument" means bringing the cleaning agent into contact with the site of the analytical instrument to which the measurement sample comes into contact. The contact may be continuous or intermittent and may be passed or retained. For example, when cleaning the flow path of a liquid chromatograph, the cleaning agent can be brought into contact with the flow path by injecting the cleaning agent into the flow path using a pump or a syringe. The cleaning agent may be brought into contact with the site where the measurement sample comes into contact by an appropriate method according to the type of the analytical instrument.

The present invention is characterized in that the cleaning effect of the protease is exerted on the contaminated portion of the analytical instrument, and then the cleaning effect of the surfactant is exerted.

In the present invention, the detergent refers to a detergent containing water as a main component and a protease or a surfactant.

The protease in the present invention may be of various origins such as animals or plants, microorganisms and the like, including chemically or genetically modified mutants, but with its characteristics such as optimum pH and coexisting substances. The compatibility of the above should be taken into consideration, and it is preferable that the content is sufficient to exert its activity. Specifically, it is 0.001-10% by weight. Examples of proteases that can be used include serine proteases (eg chymotrypsin, subtilisin, etc.), metalloproteinases (thermoricin, etc.), cysteine proteases (papain, caspase, etc.), and the like. A protease having protease activity in the range of pH 3-11 is preferable, and a mixture consisting of a protease having a wide substrate specificity or a plurality of proteases having different substrate specificities is more preferable. For example, a protease fraction derived from porcine pancreas and a protease fraction derived from bovine pancreas can be mentioned.

Examples of the surfactant in the present invention include a cationic surfactant (such as benzalconium chloride), an anionic surfactant (such as monoalkyl sulfate), a nonionic surfactant (such as octylphenolethoxylate), and both ions. It may be a surfactant (alkylamine oxide or the like) or a mixture thereof. The content of the surfactant is preferably 0.01-30% by weight.

The pH of the above-mentioned cleaning agent is preferably 3 or more and 11 or less. A buffer may also be used to maintain the pH of the cleaning agent. Examples of the buffering agent include phosphoric acid, citric acid, oxalic acid, sodium carbonate, sodium bicarbonate or a combination thereof, but there is no particular limitation. When a buffer is added to the detergent, the content of the protease or the surfactant is calculated after taking into account the content of the buffer.

Examples of the analytical instrument to be the subject of the present invention include a liquid chromatograph, a flow cytometer, a biochemical analyzer, an immunoassay, and the like, and among them, the liquid chromatograph is suitable.
Further, in the present invention, before supplying the detergent containing protease to the analysis device, after supplying the detergent containing protease to the analysis device, and before supplying the detergent containing the surfactant to the analysis device, the interface. In any case after supplying the detergent containing the activator to the analytical instrument, it is better not to supply the cleaning composition containing an organic solvent such as alcohol (methanol, etc.), ketone (acetone, etc.) to the analytical instrument. preferable.

INDUSTRIAL APPLICABILITY According to the present invention, contamination generated in an analysis device, particularly a device for analyzing a crude sample containing various substances such as a blood sample, can be safely, easily and efficiently washed.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the present Examples.

The evaluation of the contamination state of the analytical instrument and the identification of the contamination site were carried out as follows.
An Tosoh automatic hemoglobin analyzer HLC-723G8 Variant Mode (Tosoh Corporation) was used as an analytical instrument. It has been confirmed that the analytical instrument causes contamination of the sample loop very rarely due to its continuous use. As measurement samples, a distilled water diluted sample of Level-2 of the HbA1c control set (Tosoh Corporation) and a diluted sample of HSi hemolysis / washing solution (Tosoh Co., Ltd.) were used. The HbA1c% of these samples were compared. The results are shown in Table 1. When the contaminated sample loop was used, the absolute value of the difference between HbA1c% of the distilled water diluted sample and HbA1c% of the HSi hemolysis / washing solution diluted sample (hereinafter referred to as HbA1c% difference) was 0.15 points or more. Next, when a new sample loop was attached and the same measurement was performed, the HbA1c% difference was 0.05 points or less.

From the above, it was determined that the analytical instrument was in a contaminated state when the HbA1c% difference of Level-2 of the HbA1c control set was 0.15 points or more, and that the analytical instrument was in a non-contaminated state when it was 0.05 points or less. Further, when the contaminated state of the analytical instrument was resolved by exchanging the sample loop, it was determined that the contaminated portion of the analytical instrument was the sample loop.

(Example 1) Cleaning of contamination analysis equipment with a detergent composition First, the following detergents 1 and 2 were prepared.
Detergent 1 Contains 0.1% by weight of protease (Sigma-Aldrich, P4630)
10 mM phosphate buffer (pH 8.5)
Detergent 2 Polyoxyethylene (10) octylphenyl ether (hereinafter,
Triton X-100) (Kishida Chemistry, 020-81155)
10 mM phosphate buffer containing 0.1% by weight (pH 8.5)

Next, each of the four sample loops confirmed to be contaminated sites was washed under the following conditions.
Cleaning method 1 After contacting the cleaning agent 1 with the contaminated sample loop for 1 hour,
Further, the detergent 1 was brought into contact with the sample loop for 1 hour.
Cleaning method 2 After contacting the cleaning agent 2 with the contaminated sample loop for 1 hour,
Further, the detergent 2 was brought into contact with the sample loop for 1 hour.
Cleaning method 3 After contacting the cleaning agent 1 with the contaminated sample loop for 1 hour,
Further, the detergent 2 was brought into contact with the sample loop for 1 hour.
Cleaning method 4 After contacting the cleaning agent 2 with the contaminated sample loop for 1 hour,
Further, the detergent 1 was brought into contact with the sample loop for 1 hour.

Table 2 shows the results of evaluating the contamination state of the sample loop before and after cleaning according to the above criteria. In the cleaning methods 1, 2 and 4, the difference in HbA1c% after cleaning was 0.15 points or more, and the contaminated state was not resolved. On the other hand, in the cleaning method 3, the difference in HbA1c% after cleaning was 0.05 percentage points or less, and the contaminated state was eliminated. That is, it was confirmed that it is important to exert the cleaning effect of the protease on the contaminated part of the analytical instrument and then to exert the cleaning effect of the surfactant.

(Example 2) Comparison of cleaning effects depending on the type of surfactant First, the following cleaning agents 3 to 5 were prepared.
Detergent 3 Polyoxyethylene (20) Sorbitan Monolaurate
10 mM phosphate buffer (pH 8.5) containing 0.1% by weight (hereinafter referred to as Tween 20) (Wako Pure Chemical Industries, Ltd., 167-11515).
Detergent 4 Benzalkonium chloride (Tokyo Chemical Industry, B0414)
10 mM phosphate buffer containing 0.1% by weight (pH 8.5)
Detergent 5 Sodium dodecyl sulfate (Wako Pure Chemical Industries, Ltd. 196-08675)
10 mM phosphate buffer containing 0.1% by weight (pH 8.5)

Next, each of the three sample loops confirmed to be contaminated sites was washed under the following conditions.
Cleaning method 5 After contacting the cleaning agent 1 with the contaminated sample loop for 1 hour,
Further, the cleaning agent 3 was brought into contact with the sample loop for 1 hour.
Cleaning method 6 After contacting the cleaning agent 1 with the contaminated sample loop for 1 hour,
Further, the cleaning agent 4 was brought into contact with the sample loop for 1 hour.
Cleaning method 7 After contacting the cleaning agent 1 with the contaminated sample loop for 1 hour,
Further, the cleaning agent 5 was brought into contact with the sample loop for 1 hour.

Table 3 shows the results of evaluating the contamination state of the sample loop before and after cleaning according to the above-mentioned criteria of Example 1. In any of the cleaning methods 5 to 7, the difference in HbA1c% after cleaning was 0.05 percentage points or less, and the contaminated state was eliminated. That is, the surfactants used in the detergent composition include nonionic surfactants (TritonX-100, Tween20), cationic surfactants (benzalkonium chloride), and anionic surfactants (sodium dodecyl sulfate). It was confirmed that either of them may be used.

Claims (3)

After supplying a cleaning agent containing at least one type of protease and containing no organic solvent to a glycohemoglobin analyzer, a cleaning agent containing at least one type of surfactant and containing no organic solvent is supplied to the glycohemoglobin analyzer. A method of cleaning a glycohemoglobin analyzer, which comprises supplying. The method according to claim 1, wherein both the detergent containing the protease and the detergent containing the surfactant have a pH of 3 or more and 11 or less. The method according to claim 1 or 2, wherein the glycohemoglobin analyzer is a liquid chromatograph.