A comprehensive and suitable method for determining major ions from atmospheric particulate matter matrices

Abstract

The present study proposes an analytical methodology that employs ion chromatography–conductivity detection for simultaneous quantification of inorganic (F−, Cl−, NO3−, SO42−, and PO3−), monocarboxylate (HCOO−, CH3COO−, propionate, n-butyrate, lactate, and pyruvate), dicarboxylate (oxalate and succinate), and tricarboxylate anions (citrate), as well as crustal cations (Li+, Na+, K+, NH4+, Ca2+, Mg2+) at low pg m−3 range in airborne particle samples in one single run. The optimized conditions for anions were as follows: 0.6 mmol L−1 KOH for 0–14 min, 0.6–15 mmol L−1 KOH 14–20 min, 15–38 mmol L−1 KOH during 20–32 min and finally returned to 0.6 mmol L−1 for a period of 3 min, thereafter the eluent flow rate was 0.38 mL min−1. Similarly, for cations, isocratic elution was adjusted to 0.36 mL min−1 at 17.5 mmol L−1 H2SO4. LOD ranged 3.0–130 pg m−3 and LOQ was within 10–400 pg m−3 (Li+ and PO43−, respectively) as well as recoveries ranged 89% (Ca2+) to 120% (Li+). Major ions were successfully determined in real PM1 and PM2.5 samples. The method used here was found to be a comprehensive, simple, cheap and reliable procedure for studying ions in particulate matter (PM) samples even those from remote areas or near ecosystem natural conditions.