Confirmation Of Production Research Articles

A simple method for the analysis by MS/MS of underivatized amino acids on dry blood spots from newborn screening

The analysis by electrospray-ionization tandem mass spectrometry of amino acids with butyl esterification and isotopically labeled internal standard is routine in newborn screening laboratories worldwide. In the present study, we established a direct analysis method of higher accuracy that uses a non-deuterated internal standard. The automatic sampler and the pump of an LC apparatus were used to inject sample and mobile phase to MS, but no LC column was needed. The dry blood spot (DBS) material was prepared at levels of low, medium and high concentration; the running time was 1min. In parallel to the new procedure, we applied the established method to analyze nine amino acids on DBS of healthy newborns and phenylketonuria newborns. The newly proposed method of product ion confirmation scan along with multiple reaction monitoring resulted in a very accurate identification of each amino acid. Our innovative protocol had high sensitivity and specificity in the analysis of cases of suspected metabolic diseases.

A high‐sensitivity UPLC‐MS/MS method for simultaneous determination and confirmation of triptolide in zebrafish embryos

A high-sensitivity ultra-performance liquid-chromatography (UPLC) coupled with tandem mass spectrometric method was developed for simultaneous quantification and confirmation of triptolide in both zebrafish embryos and the aqueous-exposure solution on a tandem quadrupole mass spectrometer (TQ-MS). This was achieved by performing quantification using the multiple reaction monitoring (MRM) acquisition with simultaneous characterization of the MRM peak using product ion confirmation (PIC) acquisition as it elutes from the chromatographic system. Separation was achieved on a 1.7 µm C(18) UPLC column using 0.1% formic acid water-acetonitrile mobile phase with a cycle time of 6 min. The linear range of 0.115-360 ng/mL, and lower limits of detection of 0.02 ng/mL and quantification of 0.064 ng/mL were established. This method was successfully applied to determine the time course of triptolide absorption by zebrafish embryos and the amount of triptolide remaining in the culture medium after administration of two triptolide dosages at three time points. This coupled MRM with PIC approach could provide both qualitative and quantitative results without the need for repetitive analyses. This resulted in the reduction of further confirmative experiments and analytical time, and ultimately increased laboratory productivity.