WS/T 535-2017Rapid detection methods on site for disinfectant used in medical and health (English PDF)

4.1 Test paper semi-quantitative determination method

4.1.1 Scope of application

Suitable for peracetic acid, chlorine dioxide, chlorine-containing, bromine-containing, iodine-containing disinfectants, acidic oxidation potential water, glutaraldehyde, o-phthalaldehyde Rapid determination of the content of active ingredients in poisons and application solutions.

4.1.2 Operation method

4.1.2.1 At room temperature, take an appropriate amount of the disinfectant to be tested in a 25mL beaker as a sample. Take a piece of corresponding disinfectant concentration test paper, Part of the test paper is immersed in the sample, and the disinfectant concentration test paper is taken out after the time specified in the instruction manual.

4.1.2.2 Under natural light, compare the test paper with the standard colorimetric card for the time specified in the disinfectant concentration test paper, and read the concentration.

Degree value or determine whether the concentration of disinfectant meets the requirements.

4.1.2.3 If the effective ingredient content or concentration of the tested disinfectant sample is higher than the maximum limit value that can be tested by the test paper used, the sample can be used After diluting with the dilution water specified by the disinfectant manufacturer, test according to the above method, and multiply the read disinfectant concentration value by the dilution factor to obtain the original disinfectant.

The active ingredient content or concentration value of the sample.

4.1.3 Results judgment

4.1.3.1 Disinfectants for peracetic acid, chlorine dioxide, chlorine, bromine, iodine, acid oxidizing potential water, glutaraldehyde and their applications If the content or concentration of the active ingredient in the tested disinfectant sample meets the range specified in the relevant national standards and instructions for disinfection products, it is considered the effective ingredient content or concentration of the disinfectant sample meets the requirements; if the effective ingredient content or concentration of the disinfectant sample tested does not meet the corresponding country According to the scope specified in the standards and instructions, the disinfectant sample is preliminarily determined to not meet the product quality requirements, and further according to the "Disinfection Technical Specification" to determine whether the content or concentration of the effective ingredient of the product meets the corresponding requirements.

4.1.3.2 For glutaraldehyde disinfectant, if the color reaction of the tested sample on the test paper does not reach 1.8% glutaraldehyde concentration during sterilization use the standard color of the degree limit value is determined to be too low for the disinfectant to continue to be used.

4.1.3.3 For o-phthalaldehyde disinfectant, if the initial concentration of o-phthalaldehyde in the tested sample is within the range specified in the instructions, the the disinfectant sample meets the requirements; if the concentration of the tested sample does not meet the range specified in the instruction manual, it is preliminarily determined that the disinfectant sample does not meet the requirements the product quality requirements should be further tested in accordance with the requirements of Appendix A to finally determine whether the product content meets the requirements; if the product is inspected in use the color reaction of the test sample on the test paper does not reach the standard color of the o-phthalaldehyde concentration limit value specified in the instruction manual, then the disinfectant is judged the concentration is too low to continue to use.

4.1.4 Matters needing attention

4.1.4.1 The disinfectant concentration test paper shall meet the requirements of the "Regulations on Sanitation and Safety Evaluation of Disinfectants" and other requirements, and be used within the validity period.

4.1.4.2 The method of using the disinfectant concentration test paper of different products is slightly different, and the method should be operated according to the method specified in the product manual.

4.1.4.3 The concentration range of the disinfectant tested by different products is different. When the concentration is close to the upper or lower limit, the error is large. When the concentration is close to the median value, the measurement result the result is more accurate.

4.1.4.4 After opening and using, the package should be closed in time, do not contact with acid or alkali substances, and be careful not to take out the desiccant.

4.1.4.5 The disinfectant concentration test paper should be stored in a sealed, dark, dry and cool place.

4.1.4.6 When taking the test paper for detoxification agent concentration, avoid contaminating it.

4.2 Instrumental method

4.2.1 Potentially acidic oxidation water

4.2.1.1 Sampling requirements

Before testing, a water sample should be taken at the outlet of the acidic oxidation potential water, and the pH value and the oxidation reduction potential (ORP) value should be measured on site.

And available chlorine concentration (follow the method in 4.1).

4.2.1.2 PH value measurement (pH meter method)

The pH value of the stock solution of acidic oxidation potential water is 2~3, and the pH meter is calibrated with potassium hydrogen phthalate standard buffer solution (pH4.00, 20°C), Take about 60mL of the stock solution of acidic oxidation potential water in a 100mL beaker, put the pH meter probe into the stock solution of acid oxidation potential water, and read the pH after stabilization value.

4.2.1.3 Determination of oxidation-reduction potential (ORP)

Select the pH meter with the function of measuring the oxidation-reduction potential, insert the electrode (platinum electrode) for measuring the potential into the liquid to be measured, and press the pH meter "mV" You can directly measure the oxidation-reduction potential (ORP) value of the liquid.

4.2.1.4 Results judgment

The pH value measured on-site at the outlet of the acidic oxidation potential water before each use should be 2.0~3.0, and the effective chlorine concentration should be 50mg/L~ 70mg/L, oxidation-reduction potential (ORP)>=1100mV is qualified.

4.2.1.5 Notes

4.2.1.5.1 The measurement should be performed when the effluent of the acidic oxidizing potential water generator is stable. Before the pH value measurement, take the pH value of the sample solution the closer standard buffer is used to calibrate the instrument so that the displayed value of the instrument is consistent with the pH value of the standard buffer.

4.2.1.5.2 Before changing the standard buffer solution or sample solution each time, rinse the electrode with distilled water and absorb the residual water on the surface, and then use the changed Standard buffer solution or sample to be tested to rinse the electrode.

4.2.1.5.3 The water for preparing the standard buffer and dissolving the sample should be freshly boiled cold distilled water, and the pH value should be 5.5-7.0.

4.2.2 Ethanol (specific gravity method)

4.2.2.1 Detection method

Measure and record the temperature in the room, and then add an appropriate amount of ethanol sample solution to the measuring cylinder so that the alcohol hydrometer can fully float after being put in Prevail. After pressing down the hydrometer, slowly let go. When it floats and the solution has no bubbles, the alcohol meter should not touch the wall of the measuring cylinder.

The lower edge of the meniscus formed by the scale of the meter and the liquid horizontal line shall be taken as the standard to read the displayed value. Determine the ethanol content according to the density, temperature and ethanol content comparison table the amount (see Appendix B) is the volume fraction of ethanol in water.

4.2.2.2 Results judgment

The volume fraction of ethanol solution meets the requirements of GB 26373 as qualified.

4.2.2.3 Matters needing attention

This method is only suitable for unilateral ethanol disinfectant.

The absolute difference between the two independent determination results obtained by the ethanol concentration determination method under repeatability conditions shall not exceed 5% of the arithmetic mean.

Appendix A

(Normative appendix) Determination of o-phthalaldehyde content (high performance liquid chromatography) A.1 Testing equipment A.1.1 High performance liquid chromatograph.

A.1.2 Electronic balance (with a sense of 0.0001g).

A.1.3 Standard o-phthalaldehyde.

A.1.4 Acetonitrile.

A.1.5 Volumetric flask.

A.1.6 Pipette.

A.1.7 Filter membrane (0.45 µm).

A.1.8 Vacuum pump.

A.2 Detection method A.2.1 Chromatographic reference conditions A.2.1.1 Chromatographic column. C18 column (150mm×4.6mm ID, 5µm).

A.2.1.2 Mobile phase. Acetonitrile. pure water (30.70), 0.45µm membrane filtration and vacuum degassing.

A.2.1.3 Flow rate. 1.0mL/min.

A.2.1.4 Ultraviolet detection wavelength. 259nm.

A.2.1.5 Column temperature. 30°C.

A.2.2 Standard working curve A.2.2.1 Preparation of ortho-phthalaldehyde standard solution. accurately weigh 0.1g of ortho-phthalaldehyde standard into a 100mL volumetric flask, dissolve it with mobile phase and Make the volume to 100mL. Then use the mobile phase to serially dilute the ortho-phthalaldehyde standard solution to a concentration of 0 mg/L, 5 mg/L, 7.5 m g/L, 10 mg/L, 15 mg/L, 20 mg/L standard series.

A.2.2.2 Under the set chromatographic conditions, take 10µL for analysis. Take the standard series mass concentration as the abscissa X and the peak area as the ordinate Y, perform linear regression processing to obtain a linear equation.

A.2.3 Determination of o-phthalaldehyde content in samples Accurately weigh the sample and properly dilute the sample with the mobile phase so that the concentration after dilution is within the range of the standard curve, and take the appropriate diluent (10µL) After being filtered by 0.45µm filter membrane, the peak area is measured according to the above steps and substituted into the standard regression equation, according to the sampling volume and dilution factor Calculate the corresponding o-phthalaldehyde concentration. Take 3 samples and measure each sample once.

Appendix B

(Normative appendix) Alcohol and temperature correction table B.1 The 70.0-75.0 alcohol content and temperature correction table is shown in Table B.1.

B.2 The 75.5~80.0 alcohol content and temperature correction table is shown in Table B.2.