Surface microlayer enrichment of volatile organic compounds and semi-volatile organic compounds in drinking water source.

Enrichment of volatile organic compounds(VOC) and semi-volatility organic compounds(SVOC) in surface microlayer(SM) of three drinking water sources were studied. The enrichment factor(EFs) were 0.67 to 13.37 and 0.16 to 136, respectively. The results showed some VOC and most SVOC could enrich in SM. Some EFs of SVOC was quite high. Suspension and temperature could affect EFs of SVOC, slim wind and water movement do not destroy enrichment of organic in SM.

Prediction of liquid chromatography retention factors for alpha-branched phenylsulfonyl acetates using quantum chemical descriptors.

The logarithms of retention factors normalized to a hypothetical pure water eluent (log kw) were determined on a reversed-phase high-performance liquid chromatography(RP-HPLC) column (Li Chrosorb RP-18 column) for 20 new alpha-branched phenylsulfonyl acetates. The atomic charge method was applied to develop quantitative structure-retention relationships (QSRRs). Among the available geometric and electronic descriptors, surface area (S), ovality (O), and the charge of carboxyl group (Qoc) are significant. In the model, the contribution of surface area (S) is the greatest. The molecular mechanism of retention was demonstrated through the model. With the correlation coefficient (r2adj, adjusted for degrees of freedom) of 0.964, the standard error of 0.164 and the F-value of 170.39, the model has good predictive capacity.