[Preparation and application of mixed-mode capillary polymer monolithic column].

Based on the diversity of the retention mechanism, mixed-mode capillary monolithic columns have broad application prospect. In this work, a novel capillary polymer monolithic column was prepared with [2-(methacryloyloxy) ethyl] dimethyl-(3-sulfopropyl) ammonium hydroxide (SPE) as monomer, ethylene dimethacrylate (EDMA) as crosslinking agent, azobisisobutyronitrile (AIBN) as initiator and butylalcohol/1, 4-butanediol/water as ternary porogens. Under the optimized reaction conditions including the proportion of monomer and porogens, amount of initiator, reaction temperature and polymerization time, the monolithic column showed good mechanical strength up to 10 MPa, high permeability of 2. 17 x 10(-14) m2 and good repeatability. The peak area RSDs of column-to-column and batch-to-batch reproducibility were 1.0% and 4.6%, respectively. Finally, the capillary monolithic column was evaluated with polar and non-polar test mixtures. It showed hydrophilic interaction under high organic phase while hydrophobic interaction under low organic phase, indicating it a mixed-mode monolithic column.

A fully automated system with on-line micro solid-phase extraction combined with capillary liquid chromatography-tandem mass spectrometry for high throughput analysis of microcystins and nodularin-R in tap water and lake water.

Microcystins and nodularins are cyclic peptide hepatotoxins and tumour promoters from cyanobacteria. The present study describes the development, validation and practical application of a fully automated analytical method based on on-line micro solid-phase extraction-capillary liquid chromatography-tandem mass spectrometry for the simultaneous determination of seven microcystins and nodularin-R in tap water and lake water. Aliquots of just 100 µL of water samples are sufficient for the detection and quantification of all eight toxins. Selected reaction monitoring was used to obtain the highest sensitivity. Good linear calibrations were obtained for microcystins (50-2000ng/L) and nodularin-R (25-1000 ng/L) in spiked tap water and lake water samples. Excellent interday and intraday repeatability were achieved for eight toxins with relative standard deviation less than 15.7% in three different concentrations. Acceptable recoveries were achieved in the three concentrations with both tap water matrix and lake water matrix and no significant matrix effect was found in tap water and lake water except for microcystin-RR. The limits of detection (signal to noise ratio=3) of toxins were lower than 56.6 ng/L which is far below the 1 µg/L defined by the World Health Organization provisional guideline for microcystin-LR. Finally, this method was successfully applied to lake water samples from Tai lake and proved to be useful for water quality monitoring.

N'-(3-Bromo-5-chloro-2-hydroxy-benzyl-idene)-2-chloro-benzohydrazide methanol solvate.

In the title compound, C(14)H(9)BrCl(2)N(2)O(2)·CH(4)O, the dihedral angle between the two benzene rings is 49.2 (2)° and an intra-molecular O-H⋯N hydrogen bond occurs. In the crystal struture, mol-ecules are linked by O-H⋯O and N-H⋯O hydrogen bonds.