水质与灰分全氟辛烷磺酸(PFOS)和全氟辛酸(PFOA)的测定-用固相萃取和液相色谱/质谱法测定未过滤样品的方法Water quality - Determination of perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA) - Method for unfiltered samples using solid phase extraction and liquid chromatography/mass spectrometry