Application of Hydrophobic Interaction Chromatography (HIC) in Water Analysis Anwendung der Hydrophobizitätschromatographie (HIC) in der Wasseranalytik

Optimization of method for detecting and characterizing NOM by HPLC-size exclusion chromatography with UV and on-line DOC detection

High-performance liquid chromatography (HPLC)-size exclusion chromatography (SEC) with ultraviolet absorbance (UVA) and on-line dissolved organic carbon (DOC) detectors has been adapted and optimized under various conditions. An enhanced HPSEC-UVA system employing a modified commercially available DOC detector provides a better understanding of the qualitative and quantitative natural organic matter (NOM) properties in water samples by detecting aromatic and nonaromatic fractions of NOM as a function of molecular weight (MW). The most critical merit of this system is that the DOC detector is readily available and widely used. With only a few modifications, a commercially available TOC analyzer served as a DOC detector, integrated with the HPSEC to measure DOC along with UVA, and provided a specific UVA (SUVA) chromatograph that is useful information for drinking water plant design and operation. Without preconcentration, samples can be analyzed with a small amount of sample, with a DOC detection limit as low as 0.1 mg/L (as DOC).

Effects of humic substances and phenolic compounds on the in vitro toxicity of aluminium

The effects of natural chelators [humic acids (HA), caffeic acid (CFA), p-coumaric acid (PCA), protocatechuic acid (PA), vanillic acid (VA), salicylic acid (SA), and 4-hydroxyacetophenone (HY)] and effects of well-known chelators [EDTA and citric acid (CA)] on the in vitro toxicity of aluminium (Al) were investigated with the L-929 murine, Vero simian, and MRC-5 human cell lines. Moderate in vitro cytotoxic effects were induced by Al on the three cell lines (IC(50) values ranking from 5.6 to 7.6 mM). Furthermore, an increased toxicity was observed when Al was concurrently administered with CA, SA, VA, PCA, and HY. Inversely, significant cytoprotective effects were noted with EDTA, HA, CFA, and PA. The role of chelators, and especially the position and the number of reactive moieties of the phenolic compounds tested, can be highlighted to explain the different toxicological Al behavior observed.