A Rapid Determination Method for the New Sulfone Fungicide Jiahuangxianjunzuo in Goji Berry by Modified QuEChERS-Gas Chromatography Equipped with Nitrogen-Phosphorus Detector

A fast and sensitive analytical method for the determination of jiahuangxianjunzuo (JHXJZ) using gas chromatography equipped with nitrogen-phosphorus detector was developed and validated for the analysis of Goji berry which is grown in Qinghai Plateau of China. This method employs modified QuEChERS followed by detection. JHXJZ was extracted by alkaline acetonitrile [containing 1% (v/v) NH3 center dot H2O] and partitioned with a mixture of NaCl and Mg2SO4, and then cleanup was done with 30 mg GCB and 100 mg MgSO4. With this modified QuEChERS procedure, the linearity over a concentration range 0.01-5 mu g mL(-1) was good with a correlation coefficient (r) > 0.9999. Recovery at three different fortification levels was 90.40-100.9%, respectively, with a relative standard deviation < 5% for all analytes. The limits of detection and the limits of quantification were 0.003 and 0.01 mg kg(-1), respectively. JHXJZ was detected on three Goji berry food products; all positive samples showed JHXJZ contents below the legal limit established by the EU for other analogous berry-based products. These results can be used to help establish appropriate application frequencies and harvest intervals for JHXJZ on Goji berry.