1987 Volume 36 Issue 3 Pages 179-183
An application of HPLC to the determination of aldehyde concentration in rain water was examined. It was found that the following procedures were suitable for rapid and simultaneous determination of five aldehydes {HCHO, CH3CHO, C2H5CHO, C3H7CHO(n- and iso-) and C2H5CHO}. First, a rain sample should be collected by a sampler into which 10 ml of 1000 ppm HgCl2 solution is added in advance. To 1 ml of the rain water sample, 200 μl of 1000 ppm 2, 4-dinitrophenylhydrazine (DNPH) and 20μl. of 5 N H3PO4 solutions are to be added and the mixture is allowed to react for 10 min to form DNPH derivatives of the aldehydes. Then, 50 of the sample solution is injected into a C18 column with an aqueous solution of CH3CN(H2O-CH3CN= 50 : 50, v/v). The present method gave HCHO concentration in agreement with that determined by a conventional method (AHMT method), and had definitely better sensitivity: the detection limit for HCHO was 0.002Mg/ml in contrast to 0.05μ, g/ml by the latter method. The reproducibility of the measurement was about 2.5% as expressed in terms of the relative standard deviation. The aldehydes in rainwater were stable for four months when the sample was spiked with HgCl2 or CHCl3. The method established in this study was applied to the analysis of rain water collected in Nara City in a period from June, 1985 to May, 1986. The annual mean concentrations of the aldehydes turned out to be as follows : 0.262 μg/ml for HCHO, 0.146 for CH3CHO, 0.021 for C2H5-CHO, 0.01 for C3H7CHO and 0.01 for C6H5CHO.
