Ultra high performance liquid chromatography–atmospheric pressure photoionization-mass spectrometry for high-sensitivity analysis of US Environmental Protection Agency sixteen priority pollutant polynuclear aromatic hydrocarbons in oysters

Abstract

In response to Gulf of Mexico deepwater horizon oil spill, we have developed an atmospheric pressure photoionization (APPI) based ultra high performance liquid chromatography–mass spectrometry (UHPLC–MS) method for high-sensitivity analysis of United States Environmental Protection Agency (US EPA) 16 priority pollutant polynuclear aromatic hydrocarbons (PAHs) in oysters. Analyses were performed on an Agilent's Infinity 1290 UHPLC system coupled with a G6140A single quadrupole MS detector with Syagen's PhotoMate® APPI® source. Column separation was achieved using Zorbax Eclipse PAH column. Chlorobenzene was used as an APPI dopant for maximum overall sensitivity. Dynamic linear ranges were evaluated and found to cover 3.6–5.1 (Ave. 4.4) orders of magnitude with R2 of at least 0.995. A quick, easy, cheap, effective, rugged, and safe (QuEChERS) extraction and cleanup procedure was used. The spike recoveries ranged from 77% to 110% with %RSD of 0.6–6.7 at spike concentrations below or substantially below the US Food and Drug Administration (FDA) level of concern in oysters. The on-column instrument detection limits (IDLs, 6σ S/N=3) ranged from 8 to 106pg with an average of 23pg for 16 PAHs. The method detection limits (MDLs, 6σ S/N=3) ranged from 0.013 to 0.129ppm with an average of 0.040ppm for all analytes. These MDLs were about 5 times to over 4 orders of magnitude lower than US FDA levels of concern in oysters.