A method for detecting ethylene oxide

Abstract

The present application provides a method for detecting ethylene oxide, which belongs to the field of detection and analysis, and specifically relates to detecting ethylene oxide with guanidine salts, especially detecting residual ethylene oxide in reagent bottles and other items with guanidine isothiocyanate. The method of the present application can effectively determine the degree of residual ethylene oxide in the reagent bottle, thereby ensuring the stability of the performance of the reagent in the bottle after the reagent bottle is used; the entire detection process is short in duration, low in detection cost, and simple to operate.

Description

Technical Field

[0001] The present application belongs to the field of detection technology, and specifically relates to a method for detecting ethylene oxide. Background Art

[0002] Reagent bottles are mainly used to contain various chemical reagents. In order to better ensure the purity of the reagents, reagent bottles are generally sterilized by special treatment to kill various microorganisms that may be produced during the production process. The sterilization methods of plastic reagent bottles mainly include irradiation sterilization and ethylene oxide sterilization. Irradiation sterilization will turn the color of the reagent bottle yellow and is relatively expensive. Due to its low boiling point, ethylene oxide has strong penetration during low-temperature sterilization due to its strong steam pressure. Therefore, it has become a popular high-efficiency and broad-spectrum low-temperature sterilizer, which is widely used in the sterilization of medical devices, medical masks, etc. However, ethylene oxide has certain irritation and inhibition, and has stimulating and inhibitory effects on the central nervous system. In addition, ethylene oxide itself can cause cell mutations and deformities, and is a Class 1 carcinogen. Therefore, ethylene oxide residue is an important testing item for medical devices and masks. GB / T16886.7-2015 / ISO 10993-7:2008 "Biological Evaluation of Medical Devices Part 7: Ethylene Oxide Sterilization Residues" stipulates the ethylene oxide residues in medical devices, GB 19083-2010 "Technical Requirements for Medical Protective Masks", GB / T32610-2016 "Technical Specifications for Daily Protective Masks", YY 0469 "Technical Requirements for Medical Surgical Masks", YY / T 0969 "Disposable Medical Masks", GB / T38880-2020 "Technical Specifications for Children's Masks" respectively stipulate the ethylene oxide residues in medical protective masks, daily protective masks, medical surgical masks, disposable medical masks and children's masks. Secondly, ethylene oxide has relatively active chemical properties and can react with compounds containing active hydrogen. Therefore, residual ethylene oxide in the reagent bottle may affect the performance of the reagent. Currently, there is no clear standard for the detection method of ethylene oxide in reagent bottles.

[0003] At present, the detection and analysis of ethylene oxide residues are mostly concentrated in the fields of medical devices, medical and health products, cosmetics, etc., and there has been no research report on a method for simple and rapid detection of the degree of ethylene oxide residues in reagent bottles. The commonly used method for detecting ethylene oxide residues is gas chromatography, which can better control the amount of ethylene oxide residues. This method is specified in GB / T14233.1-2008 "Medical Infusion, Blood Transfusion, Injection Equipment Inspection Methods Part 1: Chemical Analysis Methods". This method is to extract the ethylene oxide contained in the sample with water extract at a certain temperature, and determine the ethylene oxide content by headspace gas chromatography. This method is relatively complicated to operate, requires the operator to have a very high technical level, and is relatively costly.

[0004] There is an urgent need for a detection technology that is simple to operate, suitable for ordinary operators, and has a lower cost to meet the requirements of detecting the residual degree of ethylene oxide in items sterilized by ethylene oxide, such as reagent bottles. Summary of the invention

[0005] The purpose of the present application is to provide a new method for detecting ethylene oxide, specifically a method for detecting ethylene oxide residues in articles, including the step of using a guanidine salt solution to detect ethylene oxide. In some embodiments, the articles are articles sterilized with ethylene oxide, such as medical devices, sanitary products, or reagent bottles. Medical devices and sanitary products include but are not limited to masks, surgical precision medical instruments, optical instruments, electronic equipment plastic products, etc. Reagent bottles refer to containers that can be used to store reagents, such as centrifuge tubes, wide-mouth reagent bottles, and narrow-mouth reagent bottles. The materials of reagent bottles include but are not limited to plastic bottles and glass bottles.

[0006] In some embodiments, the guanidine salt solution is selected from an aqueous solution of guanidine isothiocyanate, guanidine hydrochloride, guanidine sulfate, guanidine carbonate, guanidine nitrate, guanidine phosphate, guanidine acetate and / or guanidine thiocyanate. In some embodiments, the guanidine salt solution refers to an aqueous solution of guanidine salt at a concentration of 0.1-10M. In some embodiments, the guanidine salt solution refers to an aqueous solution of guanidine isothiocyanate at a concentration of 1M.

[0007] In some embodiments, the method specifically comprises:

[0008] ① The guanidine salt solution reacts with the object to be tested;

[0009] ② Detecting the pH of the solution after the reaction in step ①;

[0010] ③ Compare the pH value in step ② with the reference value, and determine whether the ethylene oxide residue of the article to be tested meets the requirements based on the comparison result.

[0011] In some embodiments, the method further comprises preparing a guanidine salt solution.

[0012] In some embodiments, the step ② is detected using a pH meter. In some embodiments, the step ② is detected using pH test paper.

[0013] In some embodiments, step ① of the method for detecting ethylene oxide is carried out at 15-30°C, specifically the reaction temperature of the guanidine salt solution and the object to be detected is 15-30°C, and the reaction time is 3-8h. In some embodiments, the reaction time of the guanidine salt solution and the object to be detected is selected from 3.5h, 4.0h, 4.5h, 5.0h, 5.5h, 6.0h, 6.5h, 7.0h, 7.5h. In some embodiments, the reference value is the pH of the control group, the control group is a group of reagent bottles that have not been sterilized with ethylene oxide, and the reference value is the pH value measured by the control group after the same steps ①② as the object to be detected. In some embodiments, the reagent bottle that has not been sterilized with ethylene oxide is a centrifuge tube that has not been sterilized with ethylene oxide, and the step ① is carried out at 15-30°C. When the pH of the object to be detected changes by less than or equal to 0.1 compared to the pH of the reagent bottle that has not been sterilized with ethylene oxide, the ethylene oxide residue of the object to be detected meets the requirements.

[0014] In some embodiments, step ① of the method for detecting ethylene oxide is carried out under heating conditions, specifically, the reaction temperature of the guanidine salt solution and the object to be detected is 40-80°C, and the reaction time is 3-8h. In some embodiments, the reaction temperature of the guanidine salt solution and the object to be detected is selected from 50-80°C, and the reaction time is selected from 3-8h. In some embodiments, the reaction temperature of the guanidine salt solution and the object to be detected is selected from 60-80°C, and the reaction time is selected from 3-8h. In some embodiments, the reaction temperature of the guanidine salt solution and the object to be detected is selected from 60-70°C, and the reaction time is selected from 4-8h. In some embodiments, the reaction temperature of the guanidine salt solution and the object to be detected is selected from 50-80°C, and the reaction time is selected from 4-8h. In some embodiments, the reaction temperature of the guanidine salt solution and the object to be detected is selected from 60-80°C, and the reaction time is selected from 4-8h. In some embodiments, the reaction temperature of the guanidine salt solution and the object to be detected is selected from 60-80°C, and the reaction time is selected from 4-8h. In some embodiments, the reaction temperature of the guanidine salt solution and the object to be detected is selected from 60-70°C, and the reaction time is selected from 4-8h. In some embodiments, the reaction temperature of the guanidine salt solution and the object to be detected is selected from 60-70°C, and the reaction time is selected from 5-7h. In some embodiments, the reaction temperature of the guanidine salt solution and the object to be detected is selected from 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C. In some embodiments, the reaction time of the guanidine salt solution and the object to be detected is selected from 3.5h, 4.0h, 4.5h, 5.0h, 5.5h, 6.0h, 6.5h, 7.0h, 7.5h. In some embodiments, the reaction temperature of the guanidine salt solution and the object to be detected is 65°C, and the reaction time is 6h. In some embodiments, the reference value is the pH of the control group, the control group is a reagent bottle group that has not been sterilized with ethylene oxide, and the reference value is the pH value measured by the control group after the same steps ①② as the object to be detected. In some embodiments, the non-ethylene oxide sterilized reagent bottle is a centrifuge tube that has not been sterilized with ethylene oxide, and step ① is performed under heating conditions. When the pH of the object to be tested changes by less than or equal to 0.1 compared to the pH of the non-ethylene oxide sterilized reagent bottle, the ethylene oxide residue of the object to be tested meets the requirements.

[0015] In some embodiments, step ① of the method for detecting ethylene oxide is carried out under heating conditions, specifically, the reaction temperature of the guanidine salt solution and the object to be detected is 40-80°C, and the reaction time is 3-8h. In some embodiments, the reaction temperature of the guanidine salt solution and the object to be detected is selected from 50-80°C, and the reaction time is selected from 3-8h. In some embodiments, the reaction temperature of the guanidine salt solution and the object to be detected is selected from 60-80°C, and the reaction time is selected from 3-8h. In some embodiments, the reaction temperature of the guanidine salt solution and the object to be detected is selected from 60-70°C, and the reaction time is selected from 4-8h. In some embodiments, the reaction temperature of the guanidine salt solution and the object to be detected is selected from 50-80°C, and the reaction time is selected from 4-8h. In some embodiments, the reaction temperature of the guanidine salt solution and the object to be detected is selected from 60-80°C, and the reaction time is selected from 4-8h. In some embodiments, the reaction temperature of the guanidine salt solution and the object to be detected is selected from 60-80°C, and the reaction time is selected from 4-8h. In some embodiments, the reaction temperature of the guanidine salt solution and the object to be detected is selected from 60-70°C, and the reaction time is selected from 4-8h. In some embodiments, the reaction temperature of the guanidine salt solution and the object to be detected is selected from 60-70°C, and the reaction time is selected from 5-7h. In some embodiments, the reaction temperature of the guanidine salt solution and the object to be detected is selected from 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, and 75°C. In some embodiments, the reaction time of the guanidine salt solution and the object to be detected is selected from 3.5h, 4.0h, 4.5h, 5.0h, 5.5h, 6.0h, 6.5h, 7.0h, and 7.5h. In some embodiments, the reaction temperature of the guanidine salt solution and the object to be detected is 65°C, and the reaction time is 6h. In some embodiments, the reference value is the pH value measured after the object to be detected is treated in step ① under non-heating conditions, that is, at 15-30°C. In some embodiments, when the pH of the object to be detected in the heating group changes less than or equal to 0.15 compared with the pH of the object to be detected in the non-heating group, the ethylene oxide residue of the object to be detected meets the requirements.

[0016] In some embodiments, the method for detecting ethylene oxide residue in an article comprises:

[0017] ① The guanidine salt solution reacts with the object to be tested;

[0018] ② Detecting the pH of the solution after the reaction in step ①;

[0019] ③ Compare the pH value in step ② with the reference value. When the comparison result meets at least one of the following conditions a) to c) , the ethylene oxide residue of the tested article meets the requirements.

[0020] a) The guanidine salt solution reacts with the object to be tested under heating conditions, the reaction temperature is 40-80°C, the reaction time is 3-8h, and the reference value is the pH value measured after the reagent bottle group that has not been sterilized with ethylene oxide is treated in the same step ① as the object to be tested, pH (object group to be tested-reference value) ≤ ± 0.1,

[0021] b) The guanidine salt solution reacts with the object to be tested under heating conditions, the reaction temperature is 40-80°C, the reaction time is 3-8h, and the reference value is the pH value measured after the object to be tested reacts with the guanidine salt solution under non-heating conditions, i.e., 15-30°C for 3-8h, pH (object group to be tested - reference value) ≤ ± 0.15,

[0022] c) The guanidine salt solution reacts with the test object at 15-30°C for 3-8h. The reference value is the pH value measured after the reagent bottle group that has not been sterilized with ethylene oxide is treated in the same step ① as the test object. pH (test object group - reference value) ≤ ± 0.1.

[0023] In some embodiments, the object to be detected is a reagent bottle, and step ① includes dispensing the guanidine salt solution into 1 / 2 volume of the reagent bottle, treating the reagent bottle at the reaction temperature, balancing the reagent in the bottle to 25° C. after the reaction time is up, and detecting the pH.

[0024] The present application provides a method for detecting ethylene oxide residue in a reagent bottle, which is as follows:

[0025] ①Prepare 1M guanidine isothiocyanate;

[0026] ② Dispense the reagents. Add 1 / 2 volume of reagent to each container. Dispense 1M guanidine isothiocyanate into centrifuge tubes and reagent bottles of various specifications to be tested. Set up 6-8 replicates for each group. Since most centrifuge tubes on the market are sterilized by high pressure or gamma ray, those that do not contain ethylene oxide can be used as controls.

[0027] ③ Reagent bottle treatment: half of the centrifuge tubes and reagent bottles containing 1M guanidine thiocyanate (3-4 replicates) were placed in a 65°C constant temperature incubator (pressurized group), and half (3-4 replicates) were stored at room temperature (15-30°C, non-pressurized group), all for 6 hours;

[0028] ④ Reagent treatment: pipette 150 μL of reagent from each centrifuge tube and reagent bottle of each specification into eight rows, place in a 25°C constant temperature bath, and equilibrate the temperature for about 5 to 10 minutes;

[0029] ⑤Measure the pH of the reagent and calibrate the pH meter. If the slope is between 95% and 105%, you can perform subsequent pH testing. Read and record the pH value of each duplicate well. Repeat the reading for 3 times for each duplicate well and calculate the average value.

[0030] ⑥Data processing and result determination

[0031] When pH (the average value of pressurized values ​​of each group - the average value of unpressurized values ​​of each group) ≤ ± 0.15, pH (the average value of unpressurized values ​​of the test group - the average value of unpressurized values ​​of the control group) ≤ ± 0.1, and pH (the average value of pressurized values ​​of the test group - the average value of pressurized values ​​of the control group) ≤ ± 0.1, 5 indicates that the residual ethylene oxide in the reagent bottle meets the requirement that the reagent bottle can store reagents.

[0032] In some embodiments, the detection system and specific operation of detecting ethylene oxide residue in the reagent bottle are as follows:

[0033]

[0034] The specific steps are as follows:

[0035] ①Prepare 1M guanidine isothiocyanate (1L, if the required reagent volume exceeds 1L, the volume can be increased by multiples)

[0036] Weigh 118.161 g of guanidine thiocyanate, add purified water (need to be heated in advance) to 600 mL, stir and mix until dissolved without particles, and add purified water to make up to 1 L;

[0037] ② Reagent dispensing

[0038] According to the packaging standard of adding 1 / 2 volume of reagent to each reagent bottle, use an electric dispenser to dispense the fully mixed 1M guanidine isothiocyanate into centrifuge tubes and reagent bottles of various specifications. Because most centrifuge tubes on the market are sterilized by high pressure or gamma ray, they do not contain ethylene oxide and can be used as a control. The specific packaging plan is as follows:

[0039]

[0040] ③Reagent bottle handling

[0041] Place half (3) of the centrifuge tubes containing 1M guanidine isothiocyanate and reagent bottles of each specification in a 65°C constant temperature incubator (pressurized group), and store half (3) at room temperature (15-30°C, unpressurized group), all for 6 hours;

[0042] ④ Reagent treatment

[0043] Pipette 150 μL of reagent from each centrifuge tube and reagent bottle of each specification into eight rows (mix the reagent thoroughly before absorbing), place in a 25°C constant temperature metal bath (adjust the temperature in advance), and equilibrate the temperature for about 5 to 10 minutes;

[0044] ⑤Measure the pH of the reagent

[0045] Calibrate the pH meter. If the slope is between 95% and 105%, you can perform subsequent pH testing. Read and record the pH value of each duplicate well. Repeat the reading for 3 times for each duplicate well and calculate the average value.

[0046] ⑥Data processing and result determination

[0047] When pH (the average value of pressurized values ​​of each group - the average value of unpressurized values ​​of each group) ≤ ± 0.15, pH (the average value of unpressurized values ​​of the test group - the average value of unpressurized values ​​of the control group) ≤ ± 0.1, and pH (the average value of pressurized values ​​of the test group - the average value of pressurized values ​​of the control group) ≤ ± 0.1, it indicates that the residual ethylene oxide in the reagent bottle meets the requirements that the reagent bottle can store reagents.

[0048] In some embodiments, the reagent bottle is used to store a nucleic acid extraction reagent containing guanidine isothiocyanate. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 The pH test results of the control group and the test group are shown.

[0050] Figure 2-1 , Figure 2-2 , Figure 2-3 The pH test results of commercially available reagent bottles are shown.

[0051] Figure 3-1 , Figure 3-2 The pH test results of the resolved and unresolved reagent bottles and the impact on the performance of the reagents stored in the bottles are shown.

[0052] Beneficial Effects

[0053] The detection method of ethylene oxide in this application is to use guanidine isothiocyanate aqueous solution to react with ethylene oxide to cause pH changes, and finally clarify the residual degree of ethylene oxide through pH changes. For the detection of ethylene oxide residues in reagent bottles, this application simulates the scene of reagent bottles containing reagents, which can effectively judge the residual degree of ethylene oxide in the reagent bottles, thereby ensuring the stable performance of the reagents in the bottles; the entire detection process only lasts 7 to 8 hours, and the operation time is only 1 to 2 hours, which greatly reduces the detection time; the detection only requires guanidine salt solution, heating equipment, micro pH meter, etc., which greatly reduces the detection cost; the detection method only requires the preparation of reagents, the packaging of reagents, and the detection of pH, which is simple and easy to use, and has low technical requirements for operators. It is suitable for the detection of the residual degree of ethylene oxide in reagent bottles, providing a guarantee for the availability of reagent bottles. DETAILED DESCRIPTION

[0054] Example 1

[0055] 1. Prepare 1M guanidine thiocyanate solution

[0056] Weigh 118.161g of guanidine isothiocyanate, add purified water to 600mL, stir and mix, wait until dissolved without particles, add purified water to 1L. This verification requires the preparation of 2L of reagent, so weigh 236.322g of guanidine isothiocyanate, add purified water to 1200mL, wait until dissolved without particles, add purified water to 2L, and set aside.

[0057] 2. Reagent dispensing

[0058] According to the standard of adding 1 / 2 volume of reagent to each reagent bottle, use an electric dispenser to dispense the fully mixed 1M guanidine isothiocyanate into centrifuge tubes and reagent bottles of various specifications, with 6 replicate wells for each. The specific plan is as follows:

[0059]

[0060] 3. Reagent bottle handling

[0061] Place half of the centrifuge tubes containing 1M guanidine thiocyanate and reagent bottles of each specification (3 in each group) in a 65°C constant temperature incubator (pressurized group, i.e., heated group), and store the other half (the other 3 in each group) at room temperature (unpressurized group), all for 6 hours.

[0062] 4. Reagent processing

[0063] Pipette 150 μL of reagent from each centrifuge tube and reagent bottle of each specification into eight rows (mix the reagent thoroughly before aspiration), place in a 25°C constant temperature metal bath (adjust the temperature in advance), and equilibrate the temperature for about 10 minutes.

[0064] 5. Measure the pH of the reagent

[0065] The pH meter was calibrated, and subsequent pH testing could be performed when the slope was between 95% and 105%. The calibration slope was 97% for this verification. The pH value of each replicate well was read and recorded. The pH value of each replicate well was repeated 3 times and the average was calculated.

[0066] 6. Data processing and result determination

[0067] Record the data and calculate the mean pH of each treatment, calculate pH (mean of each group with pressure added - mean of each group without pressure added), pH (mean of the test group without pressure added - mean of the control group without pressure added), pH (mean of the test group with pressure added - mean of the control group with pressure added). For detailed results, see Figure 1 .

[0068] Depend on Figure 1It can be seen that compared with the non-EO sterilized 50mL centrifuge tubes, the pH (pressurized mean of each group - the unpressurized mean of each group) of the EO sterilized unresolved centrifuge tubes and reagent bottles of various specifications are all >0.15, the pH (unpressurized mean of the test group - the unpressurized mean of the control group) is all >0.1, and the pH (pressurized mean of the test group - the pressurized mean of the control group) is all >0.1; the pH (pressurized mean of each group - the unpressurized mean of each group) of the EO sterilized completely resolved centrifuge tubes and reagent bottles of various specifications are all ≤0.15, the pH (unpressurized mean of the test group - the unpressurized mean of the control group) is all ≤0.1, and the pH (pressurized mean of the test group - the pressurized mean of the control group) is all ≤0.1. This method and standard can better distinguish whether there is residual ethylene oxide in the reagent bottle, and can be used for the qualitative analysis of ethylene oxide in the reagent bottle, thereby avoiding the influence of residual ethylene oxide in the reagent bottle on the reagent performance.

[0069] Embodiment 2:

[0070] The difference between this embodiment and embodiment 1 is as follows:

[0071] The reagent bottles used in step 2 of this embodiment are 55 reagent bottles of different brands and specifications on the market;

[0072] In step 3 of this embodiment, the samples were not placed at room temperature. Instead, the centrifuge tubes containing 1 M guanidine isothiocyanate and reagent bottles of various specifications were placed in a 65° C. constant temperature incubator.

[0073] Record the data and calculate the mean pH of each treatment, calculate pH (mean of each group with pressure added - mean of each group without pressure added), pH (mean of the test group without pressure added - mean of the control group without pressure added), pH (mean of the test group with pressure added - mean of the control group with pressure added). For detailed results, see Figure 2-1 , Figure 2-2 , Figure 2-3 .

[0074] Depend on Figure 2-1 , Figure 2-2 , Figure 2-3 It can be seen that among the 55 tests, 45 were found to have heavy ethylene oxide residues, as shown by pH (pressurized mean value of the test group - pressurized mean value of the control group) > 0.1. This shows that some reagent bottles currently sold on the market have heavy ethylene oxide residues, and these chemically active ethylene oxides will have serious effects on some reagents.

[0075] Embodiment 3:

[0076] The difference between this embodiment and embodiment 1 is as follows:

[0077] The test group reagent bottles used in step 2 of this embodiment are 70 mL wide-mouth reagent bottle-1 (EO sterilization without resolution) and 70 mL wide-mouth reagent bottle-2 (EO sterilization with complete resolution);

[0078] Step 3 of this embodiment is the same as that of embodiment 2.

[0079] This embodiment adds step 7: putting the extraction reagent containing guanidine isothiocyanate into the same batch of products in the above reagent bottle, leaving it at room temperature for 24 hours and then performing performance testing.

[0080] Detailed results are shown in Figure 3-1 , Figure 3-2 .

[0081] Depend on Figure 3-1 It can be seen that the pH of 70mL wide-mouth reagent bottle-1 is (test group pressurized mean value - control group pressurized mean value)>0.1, and the pH of 70mL wide-mouth reagent bottle-2 is (test group pressurized mean value - control group pressurized mean value)≤0.1, and the results are consistent with Example 1.

[0082] Depend on Figure 3-2 It can be seen that the performance test results show that the ethylene oxide residue in the 70mL wide-mouth reagent bottle-1 seriously affects the performance of the reagent, which is mainly manifested in abnormal CT value and abnormal removal efficiency (removal efficiency of DNA in the extracted RNA product).

[0083] Therefore, our testing methods and standards can guarantee the availability of reagent bottles.

[0084] This application establishes a method for detecting the residual degree of ethylene oxide in a reagent bottle by using a guanidine isothiocyanate aqueous solution method. This method simulates the scene of a reagent bottle containing reagents, is easy to operate, is suitable for ordinary operators, and greatly reduces the operation time and detection cost. It is suitable for detecting the residual degree of ethylene oxide in a reagent bottle and provides a guarantee for the availability of the reagent bottle.

Claims

1. A method for detecting ethylene oxide residue in an article, characterized in that Use guanidine salt solution to detect ethylene oxide, including: ① The guanidine salt solution reacts with the object to be tested; ② Detecting the pH of the solution after the reaction in step ①; ③ Compare the pH value in step ② with the reference value. When the comparison result meets at least one of the following conditions a)-c) , the ethylene oxide residue of the tested article meets the requirements. a) The guanidine salt solution reacts with the object to be tested under heating conditions, the reaction temperature is 40-80℃, the reaction time is 3-8h, the reference value is the pH value measured after the reagent bottle group that has not been sterilized with ethylene oxide is treated in the same step ① as the object to be tested, and the pH-reference value of the object to be tested group is ≤±0.1, b) The guanidine salt solution reacts with the test object under heating conditions, the reaction temperature is 40-80℃, the reaction time is 3-8h, and the reference value is the pH value measured after the test object reacts with the guanidine salt solution under non-heating conditions, i.e. 15-30℃ for 3-8h. The pH-reference value of the test object group is ≤±0.

15. c) The guanidine salt solution is reacted with the object to be tested at 15-30℃ for 3-8h. The reference value is the unepoxy The pH value of the ethane sterilization reagent bottle group after the same treatment as the test object in step ① is measured. The pH-reference value of the test object group is ≤±0.1; The object to be detected is a reagent bottle, and step ① includes filling the guanidine salt solution into 1 / 2 volume of the reagent bottle, treating the reagent bottle at the reaction temperature, taking the reagent in the bottle to balance to 25°C after the reaction time, and detecting the pH, wherein the guanidine salt solution is a 1M guanidine isothiocyanate aqueous solution.

2. A method for detecting ethylene oxide residue in a reagent bottle, as follows: ①Prepare 1 M guanidine isothiocyanate aqueous solution; ② Pack the reagents according to the standard of adding 1 / 2 volume of reagents to each container, and pack 1 M guanidine isothiocyanate into centrifuge tubes and reagent bottles of various specifications to be tested. Each group has 6-8 replicates. The centrifuge tubes are autoclaved or gamma-ray sterilized centrifuge tubes without ethylene oxide, which are used as controls; ③ Reagent bottle treatment: place half of the centrifuge tubes and reagent bottles containing 1 M guanidine thiocyanate, i.e. 3-4 replicates, in a 65°C constant temperature incubator as the pressurized group; and half, i.e. 3-4 replicates, at room temperature as the non-pressurized group, all for 6 hours; ④ Reagent treatment: pipette 150 μL of reagent from each centrifuge tube and reagent bottle of each specification into eight rows, place in a 25℃ constant temperature bath, and balance for 5-10 min; ⑤Measure the pH of the reagent and calibrate the pH meter. If the slope is between 95% and 105%, you can perform subsequent pH testing. Read and record the pH value of each replicate well. Repeat the reading for 3 times for each replicate well and calculate the average value. ⑥Data processing and result determination When the mean pressurized pH value of each group - the mean unpressurized pH value of each group ≤±0.15, the mean unpressurized pH value of the test group - the mean unpressurized pH value of the control group ≤±0.1, and the mean pressurized pH value of the test group - the mean pressurized pH value of the control group ≤±0.1, it indicates that the residual ethylene oxide in the reagent bottle meets the requirement that the reagent bottle can store reagents.

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