本文件规定了通过同位素稀释气相色谱-质谱（GC-MS）吹扫和捕集萃取法定量测定未过滤水样中选定的环状挥发性甲基硅氧烷（cVMS）的方法。 本方法适用于单个CVM的测定，包括: -八甲基环四硅氧烷（D4）； -十甲基环戊硅氧烷（D5）； -十二甲基环己基硅氧烷（D6）； 在地表水、地下水和废水中。它可用于浓度范围为0.01μg/l至1μg/l的每种目标化合物的样品。根据基质的不同，在适当稀释样品或减小样品尺寸后，该方法也可适用于1μg/l至100μg/l范围内的较高浓度。

This document specifies a method for the quantitative determination of selected cyclic volatile methylsiloxanes (cVMS) in non-filtered water samples by purge and trap extraction with isotope dilution gas chromatography-mass spectrometry (GC-MS). This method is applicable to the determination of individual cVMS, including: — octamethylcyclotetrasiloxane (D4); — decamethylcyclopentasiloxane (D5); — dodecamethylcyclohexasiloxane (D6); in surface water, ground water, and wastewater. It can be applied to samples within the concentration range of 0,01 μg/l to 1 μg/l of each of the target compounds. Depending on the matrix, the method may also be applicable to higher concentrations ranging from 1 μg/l to 100 μg/l after suitable dilution of the sample or reduction in sample size.