YY/T 1555.2-2018Particular requirements for the silicone gel filled breast implant—Performance requirement of silicone gel filler - Part 2: Limits requirement for extractable substances (English PDF)

3.1 Mammary implant

An implant with a shell, which is used for increasing the volume of the breast or replacing the breast. The shell can be filled with objects by a manufacturer or a surgeon. [YY 0647-2008, definition 3.5]

3.2 Filler

The contents of the implant.

B.1 Principle

Use gas chromatography to analyze the small molecules in the extract. When the vaporized sample is carried by the mobile phase into the chromatographic column for operation, it is repeatedly distributed between the two phases. Due to the different distribution coefficients of each component between the mobile phase and the stationary phase, the running speed of each component in the chromatographic column is different. After a certain column length, they are separated from each other. They leave the chromatographic column and enters the detector in sequence. The detector can convert the sample component information into an electrical signal; the size of the electrical signal is proportional to the amount or concentration of the measured component, so as to realize the detection of the measured component.

B.2 Apparatus

B.2.1 Gas chromatograph, with hydrogen flame ionization detector. B.2.2 Electronic balance (precision of 0.1 mg).

B.3 Reagents

B.3.1 Acetone, required to be analytical grade and above. B.3.2 Octamethylcyclotetrasiloxane (D4), required to be analytical grade and above. B.3.3 Decamethylcyclopentasiloxane (D5), required to be analytical grade and above.

B.4 Test methods

B.4.1 Standard solution preparation

Take about 0.05 g of D4, D5 and other oligosiloxane substances respectively; accurately weigh them; use acetone to dilute the solution to 50 mL; then, use acetone to dilute the solutions successively, to prepare mixed standard solutions of D4 and D5 oligosiloxane substances of at least 5 concentration gradients from 1 µg/mL to 50 µg/mL.

B.4.2 Gas phase determination

Chromatographic conditions:

Chromatographic column: capillary column (30 m × 0.25 mm × 0.25 µm) with 5% phenyl-95% polydimethylsiloxane as the fixed liquid;

Column temperature: 60 °C (hold for 3 min), raise to 300 °C at 10 °C/min (hold for 10 min); Inlet temperature: 280 °C; Detector temperature: 300 °C;

Carrier gas: helium or nitrogen (purity above 99.99%), flow rate of 1.0 mL/min; Injection volume: 1 µL.

Take the blank solution, standard solution, and sample solution (see A.3 for the preparation method) for the gas chromatograph test. Take a standard solution of an intermediate concentration and inject consecutively 5 times, to calculate the relative standard deviation (RSD) of the peak area of oligosiloxane substances.

B.5 Result analysis

B.5.1 Use the external standard method to analyze the test results; establish a standard working curve and a regression equation; calculate the residual amount of oligosiloxane substances in the sample according to Formula (B.1).

The measurement results are expressed as the ratio of the mass (µg) of oligosiloxane substances to the mass (g) of the test mass; the unit is µg/g, namely, mg/kg.

Where:

X - the residual amount of oligosiloxane substances, in micrograms per gram (µg/g, namely, mg/kg); c - the concentration value of oligosiloxane substances in the sample test solution, which is read on the standard curve, in micrograms per milliliter (µg/mL);

V - the volume of the added extraction solvent acetone, in milliliters (mL); m - the mass of the sample, in grams (g).

B.5.2 If the concentration value read on the standard curve is less than the minimum concentration value of the standard solution, the result is expressed by Formula (B.2):