Air oxidation of HS(-) catalyzed by an mixed-valence diruthenium complex, an near-IR probe for HS(-) detection.

The strongly near-IR-active mixed-valence diruthenium complex [Ru(2)TIEDCl(4)]Cl, where TIED = tetraiminoethylenedimacrocycle, was found to be a highly active catalyst for air oxidation of HS(-) forming polysulfide species and H(2)O(2). The reaction provides a convenient method for the detection of the HS(-) generation rate of a H(2)S donor of medical importance.

Analysis of 32 toxic natural substances in herbal products by liquid chromatography quadrupole linear ion trap mass spectrometry.

In this study, an LC-MS/MS EPI method was developed for simultaneous determination of 32 toxic natural substances in herbal products. The analytes include aconite alkaloids, lobelia alkaloids, solanaceous alkaloids, digitalis steroid glycosides, strychnine, tetrahydropalmatine etc. They werecommonly used in herbal products. The target analytes were extracted from the samples using theQuEChERS method and analysed using AB SCIEX QTRAP 5500 coupled with Agilent HPLC 1260. Thecolumn used was biphenyl reversed phase analytical column. Mobile phase A and B were deionizedwater and methanol respectively, both containing 5mM ammonium formate and 0.1% formic acid. TheMRM-IDA-EPI method enabled quantification and confirmation of the analytes in a single run. The EPIwas used for the qualitative analysis while the MRM was used for the quantitative analysis. Limits ofdetection were determined to be below 10µg/kg for the majority of the analytes. The recoveries forthose commonly detected natural substances were in the acceptable range of 70-120%.