Selective determination of substituted PAH in aerosols using liquid CO₂‐extraction, HPLC prefractionation on chemically activated silica, and HRGC combined with negative ion mass spectrometry

Abstract

SummaryA method is described which allows the determination of different substituted polycyclic aromatic hydrocarbons (PAH) such as NO2-PAH, carbazoles, keto-PAH, and aza-arenes in aerosol samples. Liquid COP-extraction is used to minimize the loss of reactive compounds. High performance liquid chromatography on chemically activated silica is employed t o prefractionate the samples into subfractions with a minimum of overlap between different PAH compound classes. Both electron capture detection and negative ion chemical ionization combined with capillary gas chromatography are used for identification and quantification. The latter method ailso allows distinction between isomers with different toxic properties when N20/CH4 reaction gas mixtures are used. Selectivity for tetrachlorodibenzo-p-dioxins as against pesticides and polychlorinated biphenyls can be improved by this techniq,ue.Theapplicability of the method is critically discussed and different examples are given.

Sub-parts-per-billion determination of nitro-substituted polynuclear aromatic hydrocarbons in airborne particulate matter and soil by electron capture-Tandem mass spectrometry

“…Among the techniques utilized to detect nitro-PAHs, the most frequently used are gas chromatography combined with, respectively, a thermionic (TID) or nitrogen-phosphorus (NPD) selective detector [13,IS,47,50,59], chemiluminescence-based thermal energy analyzer (TEA) [31][32][33][34] and electron capture detector (ECD) [44,46,57], HPLC with either fluorescence [40][41][42]45], chemiluminescence [36,51,56], or electrochemical [37,42,43,58] detector, gas chromatography-mass spectrometry (GC-MS) in electron impact (EI) [13, 16-19, 32, 34, 35, 59], positive ion chemical ionization (PCI) [9], or negative ion chemical ionization (NCI) electron capture (EC) us. 39,46,48,55,59].…”

Negative ion chemical ionization mass spectrometry - a useful technique for the selective detection of polar substituted polycyclic aromatic hydrocarbons with mutagenic properties

“…Cl on basic and acidic-buffered silica respectively(13,14). Acidic: 5 fractions, basic: 5 fractions (see(12)). 250x4.6 mm column, Lichrosorb Si-60-5 (E. Merck), Na HPO pH 8.0 or NaHSO , pH 1.0.…”

“…One aliquot was fractionated into 5 polarity ranges on the basic and one aliquot on the acidic silica surface. The same equipment and experimental conditions as described earlier(12) were used (see also TableI). Due to the reduced retention of basic polar compounds on the basic silica surface a solvent gradient to 1007.…”