Comparison of three techniques for lipid removal from seal blubber: Gel permeation, acid treatment, and dialysis with semipermeable membrane

Harbor seal blubber samples were analyzed for PCDD/Fs and PCBs by splitting the initial extract into three aliquots and applying three different techn iques for lipid removal (the first step of sample cleanup methodology for G C-HRMS analysis): gel permeation chromatography (GPC), sulfuric acid treatm ent, and dialysis through semipermeable membrane. Correlation coefficients of analyte concentrations obtained from three sets of replicate samples ran ged from 0.965 to 0.994. In addition, a number of seal blubber samples were processed without pre-extraction using only the dialysis technique. The an alyte concentrations in these samples correlated well with the analyte conc entrations obtained from dialyzed blubber extracts (correlation higher than 0.998). For all analyses (PCDD/Fs, NO- and MO-PCBs) the average surrogate standard recoveries for the GPC and dialysis techniques varied from 68 to 1 11 %. The recoveries for PCDD/Fs and MO-PCBs standards ranged from 61 to 89 % and 36 to 43% for the NO-PCBs when the acid treatment technique was used . Dialysis was proven to be an efficient technique for lipid removal of bio logical samples in comparison with the GPC and acid treatment techniques.