Simultaneous speciation analysis of inorganic arsenic and methylmercury in edible oil by high-performance liquid chromatography–inductively coupled plasma mass spectrometry

Abstract

A simultaneous speciation method of arsenic and mercury species by inductively coupled plasma mass spectrometry with a reversed-phase C18 ODS column was developed. The separation of inorganic arsenic (iAs) from As species and inorganic mercury (iHg) from methylmercury (MeHg) were achieved by HPLC with a single mobile phase containing ion-pair reagent and l-cysteine. The limits of detection of iAs and MeHg were 0.05 ng g−1 as As and 0.09 ng g−1 as Hg, respectively. The simultaneous extraction, i-As and MeHg from in edible oil were achieved using 2% (w/w) tetramethylammonium hydroxide (TMAH) solution. The proposed method was successfully applied to the food matrix type CRMs. When the simultaneous speciation was applied to several kinds of edible oil, iAs and MeHg were founded in the concentration range of 0.001 mg kg−1 to 0.010 mg kg−1 and 1.21 ng g−1 to 10.18 ng g−1, respectively.