Use of experimental design for the purge-and-trap-gas chromatography–mass spectrometry determination of methyl tert.-butyl ether, tert.-butyl alcohol and BTEX in groundwater at trace level

摘要: Abstract An efficient method for the simultaneous determination of methyl tert.-butyl ether, alcohol, benzene, toluene, ethylbenzene and xylene isomers in groundwater by purge-and-trap-gas chromatography–mass spectrometry was developed validated. Experimental design used to investigate effects temperature extraction, time extraction percentage salt added water samples. Regression models desirability functions were applied find experimental conditions providing highest global yield. Validation carried out terms limits detection (LOD), quantitation (LOQ), linearity precision. LOD values ranging from 2.6 23 ng l−1 achieved, whereas statistically verified over two orders magnitude each compound. Precision evaluated testing concentration levels. Good results obtained both intra-day repeatability intermediate precision: RSD% lower than 4.5% at 13% lowest one calculated repeatability. A sample suspected contamination leaking underground petroleum storage tanks analysed some analytes detected quantitated.