An analytical method for the determination of glyphosate and its principal metabolite, aminomethylphosphonic acid (AMPA), in water of different hardnesses (5, 20, and 30 degrees DH, french hardness) has been developed. Samples were fortified at different levels (0.05, 0.1, 1, and 5 microg/L) and were purified by column chromatography on ion-exchange resins. After derivatization with TFAA/HFB mixture, the derivatives were quantified by using capillary gas chromatography with an ion-trap tandem mass spectrometric detector. Analytical conditions for MS/MS detection were optimized, and the quantification was carried out on the sum of areas of the three most representative ions: m/z 283, 223, and 181 for AMPA and m/z 440, 321, and 261 for glyphosate. The limit of quantification was demonstrated to be at 0.05 microg/L for each compound. The mean recovery value and the relative standard deviation (n = 65) were 93 and 12% for AMPA and 95 and 13% for glyphosate.
The kinetics of the reaction between the octanucleotide d(TTGGCCAA) in the single‐stranded form in pure water and the platinum complex [Pt(NH3)3(H2O)]2+ was investigated by electrospray ionization and matrix‐assisted laser desorption/ionization (MALDI) mass spectrometries coupled with enzymatic degradation of the adducts. These methods led to the determination of specific rate constants of platination. The global rate constant characteristic of the formation of adducts on each 5′‐ or 3′‐guanine were measured by electrospray ionization analysis. The ratios between the 5′‐and 3′‐adducts were determined from enzymatic degradation of the final reaction mixture and MALDI analysis. The platination in water is approximately eight times faster than in 0.1 M NaClO4. The selectivity of platination is a factor of 2 in favor of the 5′‐guanine, and similar to that observed for the reaction between d(CTGGCTCA) and [Pt(NH3)3(H2O)]2+ in 0.1 M NaClO4.
Electrospray Ionization Mass Spectrometry (ESI/MS) has quickly become a versatile method of qualitative analysis of a wide variety of host–guest complexes formed in solution. However, considerable controversy exists on how ESI spectra quantitatively reflect and compare to the results obtained on these complexes. The extraction of alkali cations from acidic aqueous solutions by nine various calix[4]arenes-crown-6 diluted in NPOE, was studied by using ESI/MS. The stoichiometry of cesium complex and Cs+/Na+selectivity were evaluated.
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