An accurate analytical method for the determination of benzoic acid in curry paste using isotope dilution gas chromatography-mass spectrometry (GC-MS)

作者：Mak Chun yin; Wong Yee Lok^*; Mok Chuen shing; Choi Sik man

来源：Analytical Methods, 2012, 4(11): 3674-3678.

DOI：10.1039/c2ay25517k

A simple analytical procedure for the accurate determination of benzoic acid in curry paste using isotope dilution gas chromatography-mass spectrometry (GC-MS) has been developed. In brief, the analyte was extracted from the sample by steam distillation followed by liquid-liquid extraction using dichloromethane, and derivatisation before being analysed by GC-MS in selected ion monitoring (SIM) mode. Repeatability studies showed that the ID-GC-MS method was reliable and reproducible with a method precision of less than 0.6% RSD. Recoveries of fortified samples were within the range of 98.5-100.4%. The performance of the described method has also been evaluated through participation in the inter-laboratory comparison organised by the Asia Pacific Metrology Programme (APMP. QM-P14). The reported result (389 mg kg(-1)) was in good agreement with the reference value (386 +/- 8 mg kg(-1)). The relative measurement uncertainty of the method with a coverage factor of 2 (at approximately 95% level of confidence) is estimated to be 1.8%. This method may serve as an alternative method for confirmation or litigation purpose where high accuracy and high precision results are required.

• 出版日期2012-11