USE OF CAPILLARY ELECTROPHORESIS TO MONITOR CONCENTRATIONS OF ORGANIC-ACIDS IN SNOW AND RAIN WATER

Citation
S. Turcat et al., USE OF CAPILLARY ELECTROPHORESIS TO MONITOR CONCENTRATIONS OF ORGANIC-ACIDS IN SNOW AND RAIN WATER, Science of the total environment, 158(1-3), 1994, pp. 21-29
Citations number
19
Categorie Soggetti
Environmental Sciences
ISSN journal
00489697
Volume
158
Issue
1-3
Year of publication
1994
Pages
21 - 29
Database
ISI
SICI code
0048-9697(1994)158:1-3<21:UOCETM>2.0.ZU;2-N
Abstract
The concentrations of six organic acids present in snow and rain water were determined during the spring of 1992, in order to test the possi bilities of capillary electrophoresis for measurements in the environm ent. The sampling sites were located in the French Alps. Fourteen samp les were taken. This method allows routine analysis. The following aci ds, normally found in snow and rain waters, were satisfactorily separa ted after 5 min: formic, acetic, propionic, butyric, oxalic and benzoi c, with concentrations of the order of 10(-6) M. The sample size was v ery small since a 100-mu l aliquot is sufficient to perform an analysi s without previous treatment or preliminary concentration. For these t hree reasons - time, sensitivity and sample amount - capillary electro phoresis is suitable for measurements in the environment. Short sampli ng times can be used, for example, in order to follow rain events. Mon itoring organic acids in hydrometeors collected at high altitude shows that their concentrations are fairly constant for the various individ ual rain or snow samples but are different for rain and snow samples. The total concentrations observed for the five acids detected (all org anic acids except oxalic) ranged from 5 to 10 mu M for rain water and 0.5 to 5 mu M for snow. The profile established from the relative abun dance of the acids differs from snow to rain and depends on the season , which confirms that formic acid is a biogenic tracer and acetic acid is an anthropic tracer. Furthermore, we show, for the first time, tha t butyric acid is a good tracer of bacterial activity.