A DEVICE FOR SAMPLING AND DETERMINATION OF TOTAL PARTICULATE MERCURY IN AMBIENT AIR

A miniaturized device, which serves as both particulate trap and pyrol yzer for airborne particulate mercury species, is described. It has be en used in combination with amalgamation/thermal desorption/cold vapor atomic fluorescence spectrometry detection for the determination of t otal particulate mercury(TPM) associated with atmospheric aerosols, A standard reference material (SRM 1633b, NIST) has been used for valida ting of the pyrolysis technique, and a relative error smaller than 3% has been obtained. Contrary to most methods currently employed, this n ew technique does not require any sample preparation (e,g., extraction /digestion), no manual sample transfer or sample handling, and no addi tion of chemicals or reagents. Hence the risk of contamination is low. The time for complete analysis is less than 10 min per sample. The co ncentrations of TPM determined in metropolitan Toronto ranged from 3 t o 91 pg m(-3) with standard deviations of <+/-2 pg m(-3) for simultane ous sets of four samples. These atmospheric TPM concentration values f all within the range reported in the literature. Good agreement was ob tained by the three methods compared in a held study at Ny-Alesund (78 degrees 54'N, 11 degrees 53'E), Svalbard. The elevated values of TPM concentrations obtained using the method developed in this work may ar ise from the Arctic springtime conversion of atmospheric mercury from gas-phase to particulate-phase Hg species.