engleski

Analysis of organochlorine pesticides and PCB congeners in atmospheric fine particles

An analytical procedure was developed for determination of semivolatile persistent organochlorine (OC) micropollutants in samples of atmospheric particles PM_10 and PM_2.5. The compounds analysed were hexachlorobenzene, alpha-, beta-, and gamma-hexachlorocyclohexane, 4, 4'-DDT, 4, 4'-DDE, 4, 4'-DDD, and twenty polychlorinated biphenyl (PCB) congeners: PCB-28, PCB-52, PCB-60, PCB-74, PCB-77, PCB-101, PCB-105, PCB-114, PCB-118, PCB-123, PCB-126, PCB-138, PCB-153, PCB-156, PCB-157, PCB-167, PCB-169, PCB-170, PCB-180, and PCB-189. Twenty-four-hour samples of PM_10 and PM_2.5 particle fractions were collected on glass microfibre filters from approximately 100 m^3 of ambient air at the average air flow rate of 70 L/min. The filters with particle samples collected during seven consecutive days were combined for chemical analysis. The collection and analysis of seven-day air samples instead of seven combined 24-hour samples failed because of considerable volatilisation losses leading to an underestimation of particle bounded micropollutants. OC compounds were accumulated from particles by sonicated multiple extraction with 1:1 acetone:n-hexane mixture. The extracts were purified with sulphuric acid and analysed by high resolution gas chromatography with electron capture detection. The procedure was optimised by analysis of blank filters and filters with particles spiked with nanogram amounts of analysed compounds. At ng/mg mass fraction levels the extraction recoveries ranged from 52 to 102% depending on the compound. OC compound detection limits in atmospheric particles, estimated by analysis of real samples collected at a location in the northern, residential part of the Zagreb city, ranged from 0.4 to 0.8 pg/m^3.

Organochlorine pesticides; PCB congeners; atmospheric particles

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