YY/T 1690-2020Determination of residual of ethylene chlorohydrin(ECH) from plasticized polyvinyl chloride infusion equipments for single use (English PDF)

4.1 General

There are two basic extraction methods used to determine the ECH residues of medical devices. The simulated use of extraction is the standard method, and the limit extraction Law is an acceptable alternative in certain situations. The selected extraction method should be able to represent the greatest risk to patients in the expected use of the product It is not only the pursuit of analysis efficiency or minimizing the apparent concentration of residues.

Small instruments should be placed in a suitable container for extraction. When the device is too large for complete extraction, it may be necessary to select several representative The device components are extracted to ensure the credibility of the data.

To select a representative part of the device, either of the following two methods can be used. If it contains several different materials, each group The proportion of the total mass of the sample should be consistent with the proportion of the total mass of the component in the total mass of the device under test. Another alternative is to choose The evaluation certificate is to test the component with the highest residual content on the device, and the selected method should be confirmed.

4.2 Simulated extraction (standard method)

Use the discussed liquid that represents the most unfavorable actual clinical contact and the extraction method and conditions for extraction, and then take part of the extraction The extract is tested. In the simulated use extraction method, water is usually used as the extraction liquid.

Due to the large differences in the clinical use of the equipment, especially the actual contact of the infusion equipment with a wide variety of media, the simulated immersion When mentioning, if the test medium produces interference under the test conditions specified in Chapter 5, other conditions demonstrated by methodology should be used.

4.3 Ultimate extraction (acceptable alternative method)

The limit extraction method is used to determine the total amount of residue on the device. The limit extraction method is an acceptable alternative and can provide useful information.

Information, the measured results indicate greater than or equal to the patient's acceptable dose. Because this extraction method eliminates the influence of time on dosimetry There is no guarantee that most of the residual amount measured will be released to the patient on the first day of contact with the device or at the end of the first month.

Note. If the limit extraction test results exceed the maximum allowable human dose, consider using simulated extraction (4.2) to prepare extracts for further testing.

5 Recommended determination method---limit extraction headspace gas chromatography

5.1 Reagents

ECH reference substance. purity not less than 95.0%, CAS number. 107-07-3.

5.2 Apparatus and equipment

Headspace-gas chromatograph (FID detector).

5.3 Working standard solution

Take a dry and clean 100mL volumetric flask, add about 40mL water, add a stopper, and accurately weigh. Take a certain amount of ECH and add capacity In the bottle, do not add the stopper, shake it gently, cover the stopper, and weigh it accurately. The difference between the two weighings is the weight of ECH contained in the solution. add water To the mark, prepare a standard stock solution with a concentration of about 2000mg/L.

Prepare ECH series standard solutions with a concentration range of 4mg/L~100mg/L with standard stock solution, and prepare at least 5 concentrations.

5.4 Gas chromatographic conditions (recommended)

5.4.1 Headspace conditions

a) Heating box temperature. 90°C;

b) Heating time. 30min.

5.4.2 Chromatographic conditions

a) Capillary column. 6% cyanopropyl phenyl-94% dimethyl polysiloxane (30m×0.25mm×1.4µm) or equivalent color Spectrum column;

Note. If an equivalent column is used, the chromatographic conditions may be inconsistent.

b) Inlet temperature. 250°C;

c) Injection volume. 1mL; Split ratio. 5.1;

d) Oven temperature. hold at 50°C for 3min, heat up to 100°C at a rate of 10°C/min, hold for 2min;

e) Flow rate. 1.5mL/min; Carrier gas. N2;

f) Detector. FID; temperature. 300°C.

5.5 Measurement and result analysis

5.5.1 Preparation of test solution

Take the complete product or representative parts for the test, cut into 0.5cm long pieces (or 10mm² flakes), take 1.0g into 20mL In the headspace bottle, precisely add 5 mL of water, seal, and equilibrate at 90°C for 30 min.

5.5.2 Determination of standard solutions and samples

Take 5mL each of the prepared standard solution and the prepared test solution, place them in a 20mL headspace bottle and seal them according to the headspace conditions and chromatography Condition determination.

5.5.3 Quantitative analysis

The external standard method is used to analyze the working standard solution and sample solution respectively, establish the working standard curve and regression equation, and calculate the sample The residual amount of ECH. ECH residual content can be expressed in absolute content or relative content.