Rain water, chromatogram

Typical chromatograms obtained for a rain water and a river water are shown in Fig. 2.6. 

Simultaneous analysis of both anions and cations indicates that water samples from various localities contain many of the same ions but in differing amounts. Fig. 2.24 illustrates typical chromatograms of tap water and rain water. 

An anion chromatogram of the rain water sample is shown in Figure 2. The upper ion chromatogram represents a sample where TEA was added to the rain collector before sampling. In the sample to which TEA was added, S(IV) was determined to be 2.3 pM. On the other hand, only traces of S(IV) were detected in the sample without TEA because of the rapid S(IV) oxidation. Therefore, the addition of TEA to sample enables the determination of S(IV) in rain water. 

Apart from the obligatory membrane filtration (0.45 pm), the only sample preparation in the analysis of rain water, ground water, and swimming pool water is a dilution with de-ionized water. Figure 9-9 shows a cation chromatogram of a rain water sample [42] that applies non-suppressed conductivity detection the sample was injected without any dilution because of its low electrolyte content. Metrosep Cation 1-2 served as the separator column and the eluant was a mixture of tartaric acid and pyridine-2,6-dicarboxylic acid. 

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