Determination of 4-Hexylresorcinol in Shrimp Samples by Solid Phase Extraction Ultra Performance Liquid Chromatography-Tandem Mass Spectrometry.

A method for the rapid determination of 4-hexylresorcinol (4-HR) residue in shrimp by solid phase extraction (SPE) ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was established. 4-HR was extracted twice with methanol, and the extract was formulated into methanol-water solution (1:1). After being cleaned up and concentrated by a PRIME HLB solid phase extraction column, the sample was analyzed by UPLC-MS/MS and quantitatively determined by an external standard method. The separation was performed with a gradient system consisting of water and acetonitrile as the mobile phase. Monitoring was performed by electrospray ionization (ESI) in negative ion mode using multiple ion reaction monitoring (MRM). Good linearity was obtained in the concentration range of 1.0⁻100.0 μg/L, with correlation coefficients larger than 0.999. The limit of detection (LOD) was 0.25 μg/kg and the limit of quantification (LOQ) was 0.80 μg/kg. The average recoveries of 4-HR at spiked concentrations of 2.40, 6.40 and 16 μg/kg ranged from 81.35% to 94.68% with the relative standard deviations (n = 6) from 3.57% to 6.86%. The results showed that the method is simple, fast, sensitive, reliable, and reproducible; thus, it could be used as a rapid confirmation and quantitative analysis method of 4-HR residue in aquatic products.