(S)-1-(5-(4-Methylpiperazin-1-yl)-2,4-dinitrophenyl)pyrrolidine-2-carboxylic acid (Pro-PPZ) was employed as a chiral derivatization reagent (CDR) for the efficient enantioseparation and ultrasensitive mass spectrometric detection of chiral amines. Pro-PPZ was prepared from the one-step reaction of 1-(5-fluoro-2,4-dinitrophenyl)-4-methylpiperazine (PPZ) and l -proline. Two amines and two amino acid methyl esters were selected as model chiral amines, which were easily labeled with Pro-PPZ under mild reaction conditions (35 °C for 10 min) generating Pro-PPZ-amine derivatives. The resulting diastereomers were completely separated by reversed-phase liquid chromatography (RP-LC) using an ODS column ( R s = 3.4–17.0 for amines). Ultrasensitive detection limits on femtomolar level were obtained for the tested amines using multiple reaction monitoring (MRM) chromatograms at a single monitoring ion, m/z 289 (0.1–5.0 fmol for amines). The practical metabolite analysis of (R)-1-aminoindan (R-AI) in saliva samples was performed by LC–MS/MS using the Pro-PPZ derivatization method. The method was validated in terms of precision, accuracy, and linearity. Using this method, R-AI concentrations in saliva were determined after a single oral administration of the drug rasagiline to healthy male and female subjects, but no (S)-1-aminoindan (S-AI) was detected, which suggesting that R-AI was not converted into S-enantiomer in the metabolic process. R-AI concentrations in four healthy volunteers ranged from 32.85 nM to 49.45 nM, with an average value of 43.76 nM. To date, there is no LC–MS (or MS/MS) method reported for the enantioselective determination of R-AI in human saliva samples.
As an ideal alternative to bisphenol A (BPA), bisphenol S (BPS) has similar biotoxicity, teratogenicity , carcinogenicity and mutagenicity as BPA. Nevertheless, to date, a fast, sensitive and portable method for meeting on-site measurement of BPS had not been established. Hence, it was particularly urged to develop a fast and highly sensitive method for tracing BPS. Currently, a novel molecularly imprinted polymer (MIP) electrochemical sensor had been successfully fabricated for the detection of BPS, wherein the composite of three-doped carbon quantum dots (B, N, F-CQDs) and silver nanoparticles (AgNPs) were utilized as an electron conducting layer, and MIP was applied as recognition element of target molecules. The step-by-step fabrication process and the adsorption capacity of the modified electrode were evaluated by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and chronocoulometry (CC). The results indicated that the synergy between B, N, F-CQDs and AgNPs dramatically improved the sensitivity of the electrode and achieved the amplification of the electrical signal. Meanwhile, the electrochemical activities of BPS were explored by CV and differential pulse voltammetry (DPV). And, the various parameters relating to the electrochemical kinetic properties of BPS were calculated. To the best of our knowledge, this was rarely reported in peer journals. The MIP remarkably improved the selectivity of the sensor owing to the specific recognition of the imprinted cavities. The linear response range of the new sensor was 1 × 10 −8 M to 5 × 10 −5 M with a detection limit of 1.12 × 10 −8 M and the electrode designed in this paper could meet the requirement of trace-level measurement of BPS in biological and environmental samples. Additionally, the sensor was used to determine BPS in plastic products with good anti-interference and acceptable recovery.
危险品化学品经营许可证（带存储）