Two highly sensitive methods for the determination of genotoxic alkyl methane sulfonates (AMSs) and alkyl paratoluene sulfonates (APTSs) in lamivudine using hyphenated techniques have been presented by N.V.V.S.S. Raman et al. (2012). AMSs were determined by GC–MS method using GSBP-INOWAX (30 m×0.25 mm×0.25 μm) column. Temperature program was set by maintaining at 100 °C initially for 3 min, then rised to 220 °C at the rate of 15 °C/min and maintained at 220 °C for 16 min. N,N-dimethyl formamide was used as diluent. APTSs were determined by LC-MS using Zorbax, Rx C8, 250 mm×4.6 mm, 5 μm column as stationary phase. 0.01 M ammonium acetate is used as buffer. The mixture of buffer and methanol in 75:25 (v/v) ratio was used as mobile phase A and …show more content…
(1977) have developed a method for determination of sodium alkyl sulfonates. The sodium alkyl sulfonates (PS) prepared from paraffin by sulfoxidation reaction are used as effective anionic detergents. The products are mixture of secondary sulfonate isomers. The analysis of each isomer is important for the elucidation of reaction mechanism of sulfoxidation and their physical properties. The authors carried out the isomer analysis of PS by means of Nuclear magnetic resonance spectroscopy (NMR) method with the NMR shift reagent, Eu (dpm). In the ordinary NMR spectrum of methyl alkyl sulfonate, the information on the position of sulfonicgroup could not be obtained. It was found that methyl signals of ester group shift toward lower fields by addition of a suitable amount of shift reagent. The difference in magnitude of the induced chemical shift was clearly related to the positions of sulfonic groups. The order of induced chemical shift of the methyl signal was 1, 2, 3, 4, 5, 6 and 7-9 methylsulfonate, respectively. Sulfonate isomers in PS can be determined by using the area of the peak of methyl signal of ester group for each …show more content…
Lee et al. (2003) reported a new method for the determination of the methyl, ethyl and isopropyl esters of methanesulfonic acid, and of dimethyl sulfate. Derivatisation with aqueous sodium thiocyanate gives a mixture of the corresponding alkylthiocyanates and alkylisothiocyanates which, unlike the underivatised analytes, are readily analysed by GC. On-column isomerisation is negligible. These lower alkyl derivatives are sufficiently volatile for static reaction headspace analysis, and detection limits obtained by electron impact MS are below 0.05 µg ml−1 with respect to the injection solution. The method was used to demonstrate that levels of methanesulfonic acid esters in a drug substance (a mesylate salt that had been processed using methanol and ethanol) are below 1 µg