CORRECTION OF ANALYTICAL RESULTS FOR RECOVERY: DETERMINATION OF PAHsIN AMBIENT AIR, SOIL, AND DIESEL EMISSION CONTROL SAMPLES BY ISOTOPE DILUTION GAS CHROMATOGRAPHY-MASS SPECTROMETRY

Results from soil, diesel emission and ambient air control particulate matter samples on the determination of 30 PAHs were evaluated to establish whether the use of recovery data would result in an improvement of the quantitation accuracy over the uncorrected data. The performance of the recovery-corrected technique was initially evaluated using recovery results from PAH standard reference material samples spiked with analogue deuterated isotopes. The results showed an excellent correlation between recoveries of natives and corresponding surrogates for all matrices studied. The practical merit of the isotope dilution mass spectrometry technique was further assessed by spiking control samples with corresponding isotopic analogues and comparing the measured concentration of natives obtained with uncorrected and recovery-corrected techniques. The data revealed that the use of recovery correction leads to results closer to the real values, thus decreasing the negative bias due to losses that occur during the ...