Determination of organic acid anions in precipitation by ion chromatography exclusion

✍ Scribed by Susan R. Bachman; Mark E. Peden

• Publisher: Springer Netherlands
• Year: 1987
• Tongue: English
• Weight: 420 KB
• Volume: 33
• Category: Article
• ISSN: 0049-6979
• DOI: 10.1007/bf00191387

✦ Synopsis

A method for the determination of organic acid anions in precipitation samples is described. The technique of ion chromatography exclusion (ICE) is used to identify and quantify the more commonly found anions of the acids citric, formic and acetic in central Illinois rainwater. By using a two column system consisting of a separator and suppressor, method detection limits (MDL) of 0.03 mg L -~ for each of the three anions are obtained. The total analysis time for quantitation is 24 min. Samples collected from early spring rains contained primarily formate and acetate ions with levels of concentration ranging from 0.03 to 0.44 mg L-i. The organic acids formic and acetic contributed approximately 8 % to the total acidity in the precipitation samples analyzed. Precision averaged 5% as the relative standard deviation (RSD) and analyte spikes of natural precipitation samples revealed a mean recovery of greater than 99 %. A preservation technique using chloroform (CHC13) addition is discussed with results indicating its necessity in maintaining original organic anion concentrations.