Fast and sensitive detection of acrolein in environmental water samples without derivatization using liquid chromatography tandem mass spectrometry

Synephrine, as a scavenger and promoter, cooperates with hesperidin to reduce acrolein levels

Acrolein (ACR) is a harmful and active aldehyde produced in processed food that endangers foods safety. We undertook this work to explore the ACR-trapping ability of hesperidin (HES) and synephrine (SYN) from the diet. After comparing their ACR-trapping abilities, the reaction pathways of HES and SNY were analyzed using LC-MS/MS, and two adducts (HES-ACR-1 and SNY-2ACR) were synthesized, and their structures were identified by NMR. Then, we not only evaluated the synergistic trapping effects of HES and SNY on ACR in the model through the Chou-Talalay method but verified it in the processing of roasted duck wings and cookies. Furthermore, based on the quantitative analysis of the ACR-adducts of HES and SNY, we demonstrated that SYN, as a promoter, could greatly improve the ACR-capturing ability of HES by forming more adducts (3-fold). Our findings could serve as a guide for using SNY and HES as new scavengers in food processing.

A novel method based on solid phase extraction and liquid chromatography-tandem mass spectrometry warrants occurrence of trace xanthates in water

Huge volumes of wastewater containing organic flotation reagents such as xanthates have been released into the environment via mining activities, greatly threatening the eco-environment safety. A simple and fast method is urgently needed for accurate analysis of various xanthates in mining and environmental water. Here, a robust method is realized for simultaneous determination of three trace xanthates (i.e., potassium ethyl xanthate, potassium butyl xanthate, and potassium isopropyl xanthate) in environmental water samples, including eutrophic water and flotation wastewater using solid phase extraction (SPE) and HPLC-MS/MS. HPLC-MS/MS parameters, SPE cartridges and eluting solvents, pH values, and SPE procedures were optimized. The new method had an excellent linearity in the range of 1-1000 μg/L (R² ≥ 0.998), low limits of detection (0.02-0.68 μg/L), and satisfactory accuracy and precision (72.9%-107.6% of average recoveries and <5% of relative standard deviations at 1, 10, 50, and 500 μg/L of xanthates). This is a first method developed for determination of trace xanthates in water samples. It was successfully applied to determine the target analytes in outdated flotation wastewater and river water samples, warranting the occurrence of trace xanthates (0.13-16.9 μg/L) in water and necessity of systematic investigation on environmental fate and risk of xanthates.

Sensitive detection of antidiabetic compounds and one degradation product in wastewater samples by a new SPE-LC-MS/MS method

As environment emerging contaminants of anthropogenic origin, antidiabetic drugs are present in the range of high ng/L to ng/mL in the influent and the effluent of the waste water treatment plant (WWTP). The metformin compound is the most used hypoglycemic agent in the world. The aim of this study was to develop a new analytic method, based on solid phase extraction followed by liquid chromatography coupled with mass spectrometric detector (SPE-LC-MS/MS), for identification and quantification of 5 antidiabetic compounds (glibenclamide/glyburide, glimepiride, metformin, glipizide, guanyl urea, gliclazide) and one degradation product (guanyl urea). The investigated environmental samples were the influent and the effluent of four urbans WWTP's. By validating of the analytical method, it was obtained low LOQ's (0.2-4.5 ng/L), satisfactory recovery rates (53.6-116.8%), and corresponding performance parameters: inter-day precision (4.9-8.4%) and reproducibility (11.3-14.6%). The concentrations of antidiabetics were as follow in influent and effluent: metformin 76-2041ng/L and 2-206ng/L, gliclazide (14.1-42.4 ng/L, and 3.3-19.1), glipizide (7.5-11.2 ng/L and 6.5-10ng/L), guanyl urea (6.2-7.3 and 8.3-21.3 ng/L). The efficiency of elimination of the antidiabetics in WWTP's was maximum for metformin (67.6-98.5%), followed, by gliclazide (72.9-78.2%). The lowest elimination efficiency was calculated for glipizide (10.7-13.3%). The guanyl urea undergoes a formation process (74.5-84.2%) in effluent, from the metformin contained in influent.

Miniaturized solid-phase extraction using a mesoporous molecular sieve SBA-15 as sorbent for the determination of triterpenoid saponins from Pulsatilla chinensis by ultrahigh-performance liquid chromatography-charged aerosol detection

A simple, sensitive and efficient solid-phase extraction method, combined with ultrahigh-performance liquid chromatography-charged aerosol detection, was applied to the pre-concentration and determination of four triterpenoid saponins from Pulsatilla chinensis (P. chinensis) ultrasound extract samples. Mesoporous molecular sieve Santa Barbara Amorphous 15 (SBA-15) displayed higher selectivity compared to Mobil Composition of Matter 41 (MCM-41), NH₂-SBA-15 and mesoporous carbon when it comes to being used in pretreatment methods. It was applied as an effective sorbent in the SPE for the enrichment of the target analytes. Additionally, several key experimental parameters including the kinds of sorbents, the amount of SBA-15, the elute pH and types of elution solvent were investigated in detail. Under the optimized conditions, the satisfactory linearity (r² ≥ 0.9940) was acquired and the limits of detection reached 0.461-0.976 μg/mL for the target analytes. The recoveries ranged from 95.1%-103.2%. The experimental results showed that SBA-15 was a candidate material for the purification and concentration of target triterpenoid saponins from complex P. chinensis samples. The study provided theoretical support for the application of mesoporous materials in the field of drug separation and provided references for the extraction and determination of trace compounds in the complex systems of traditional Chinese medicine.