Restricted Access Volatile Supramolecular Solvents for Single-Step Extraction/Cleanup of Benzimidazole Anthelmintic Drugs in Milk Prior to LC-MS/MS

Preparation and evaluation of fenbendazole methyl-β-cyclodextrin inclusion complexes

As an orally effective benzimidazole anthelmintic agent, fenbendazole was not only widely used in agriculture and animal husbandry to prevent and treat parasites, but also shows anti-cancer effects against several types of cancer, exhibits anti-cancer effects in paclitaxel and doxorubicin-resistant cancer cells. However, fenbendazole's poor in water solubility (0.3 µg/mL), limits its clinical applications. Even great efforts were made toward increasing its water solubility, the results were not significant to reach anti-cancer drug delivery requirement (5-10 mg/mL). Through single factor and orthogonal strategy, many complex conditions were designed and used to prepare the complexes, the inclusion complex with methyl-β-cyclodextrin with 29.2 % of inclusion rate and 89.5% of inclusion yield can increase drug's water solubility to 20.21 mg/mL, which is the best result so far. Its structure was confirmed by differential scanning calorimetry, scanning electron microscopic image, 1D and 2D NMR spectra in D2O. In its in vitro pharmacokinetic study, fenbendazole was 75% released in 15 min., in its in vivo pharmacokinetic study, the bio-availabilities of fenbendazole, its major metabolic anthelmintic agent oxfendazole and its minor metabolic anthelmintic agent oxfendazole were increased to 138%, 149% and 169% respectively, which would allow for fewer drug doses to achieve the same therapeutic effect and suggest that the complex can be used as a potential anticancer agent.

Impacts of garbage classification and disposal on the occurrence of pharmaceutical and personal care products in municipal solid waste leachates: A case study in Shanghai

Leachate generated during the treatment and disposal of municipal solid wastes (MSWs) can be an important source of pharmaceutical and personal care products (PPCPs) in the environment. With the implementation of garbage classification policy in China, the disposal methods of MSWs have changed, while its impacts on the occurrence of PPCPs in the generated leachate remain unknown. In this study, we investigated 49 target PPCPs in the leachates of classified MSWs, i.e. residual waste leachate (RWL) and food waste leachate (FWL), and revealed the influence of garbage classification implementation on the occurrence of PPCPs in leachates to be treated. The results showed the concentration and mass load of target PPCPs in the RWL samples (median values: 34.9 ng/L and 52.3 mg/d, respectively) were significantly higher than those in the FWL samples (median values: 19.3 ng/L and 14.5 mg/d, respectively). Macrolide (ML) antibiotics were the predominant PPCPs in the RWL samples, while in the FWL samples, quinolone (QL) antibiotics exhibited the highest concentration and mass load. The implementation of garbage classification policy led to the reduction of PPCP mass load (from 739 g/d to 262 g/d) in leachates to be treated. The findings are helpful for better designing or managing MSW treatment and disposal processes to minimize the emission of PPCPs from MSW leachates.

Multiclass Comparative Analysis of Veterinary Drugs, Mycotoxins, and Pesticides in Bovine Milk by Ultrahigh-Performance Liquid Chromatography-Hybrid Quadrupole-Linear Ion Trap Mass Spectrometry

A multiclass and multiresidue method for simultaneously screening and confirming veterinary drugs, mycotoxins, and pesticides in bovine milk was developed and validated with ultrahigh-performance liquid chromatography–hybrid quadrupole–linear ion trap mass spectrometry (UHPLC-Qtrap-MS). A total of 209 targeted contaminants were effectively extracted using an optimized QuEChERS method. Quantitative and qualitative confirmation were achieved simultaneously by multiple reaction monitoring–information-dependent acquisition–enhanced product ion (MRM-IDA-EPI) scan mode. The validation results exhibited a good sensitivity with the LOQs of 0.05–5 μg/kg, which was satisfactory for their MRLs in China or EU. The recoveries of in-house spiked samples were in the range of 51.20–129.76% with relative standard deviations (RSD) between replicates (n = 3) 0.82% and 19.76%. The test results of 140 milk samples from supermarkets and dairy farms in China showed that cloxacillin, aflatoxin M1, acetamiprid, and fipronil sulfone were found with lower concentrations. Combined with the residue results from the literature, penicillin G and cloxacillin (beta-lactams), enrofloxacin and ciprofloxacin (fluoroquinolones), and sulfamerazine (sulfonamides) were more frequently detected in different countries and need to receive more attention regarding their monitoring and control.

Pretreatment and determination methods for benzimidazoles: An update since 2005

Benzimidazoles, commonly used as pesticides and veterinary drugs, have posed a threat to human health and the environment due to unreasonable use and lack of valid regulation. Therefore, an up-to-date and comprehensive summary of the pretreatment and analytical approaches in different substrates is urgently needed. The present review consequently updates and covers various newly developed pretreatment methods (e.g., cationic micellar precipitation, magnetic-solid phase extraction, hollow fiber liquid phase microextraction, disperse liquid-liquid microextraction-solidified floating organic drop, stir cake sorptive extraction, solid phase microextraction method, QuEChERS, and molecular imprinted polymer-based methods) since 2005. The review also elaborates and discusses different determination methods (e.g., newly developed HPLC and related methods, improved spectrofluorimetry methods, capillary electrophoresis, and the electrochemical sensor). Furthermore, some critical points and prospects are highlighted, to describe the trends in this area.

Interference Free Method for Determination of Benzodiazepines in Urine Based on Restricted Access Supramolecular Solvents and LC-MS/MS

Supramolecular solvents with restricted access properties (SUPRAS-RAM) are proposed as a new approach for integrating extraction and sample cleanup in the quantification of benzodiazepines in urine by liquid chromatography tandem mass spectrometry (LC-MS/MS). The SUPRAS-RAM was synthesized in situ in the urine by the addition of 1- hexanol (154 µL) and THF (600 µL). Benzodiazepines extraction was driven by both hydrogen bonds and dispersion interactions. Removal of proteins and polar macromolecules was performed by the action of the SUPRAS through chemical and physical mechanisms. Phospholipids were removed by precipitation during SUPRAS extract evaporation. A multivariate method was used for the optimization of the extraction process by applying Box-Behnken response surface design. The proposed method was validated according to the guiding principles of the European Commission Decision (2002/657/EC). Method detection and quantification limits for the target benzodiazepines were in the intervals 0.21-0.85 ng/mL and 0.67-2.79 ng/mL, respectively. The repeatability and reproducibility (expressed as relative standard deviations) were in the range 2-6 % and 3-8%, respectively. The method enabled the simultaneous extraction of benzodiazepines (recoveries in the range 84-105%) and the removal of matrix effects. The method was applied to the analysis of 13 urine samples using external calibration. Five out of 13 samples tested positive in alprazolam and lorazepam at concentrations in the range 5.4-74 ng/mL. The method allows simple and quick sample treatment with minimal solvent consumption while delivering accurate and precise data.

Restricted access supramolecular solvent based magnetic solvent bar liquid-phase microextraction for determination of non-steroidal anti-inflammatory drugs in human serum coupled with high performance liquid chromatography-tandem mass spectrometry

A hexafluroisopropanol (HFIP)-alkanol supramolecular solvent (SUPRAS) based magnetic solvent bar (MSB) liquid-phase microextraction (LPME) method was proposed for extraction of non-steroidal anti-inflammatory drugs (NSAIDs, including ketoprofen, naproxen, indomethacin and diclofenac) in human serum. The restricted access HFIP-alkanol SUPRAS was prepared by injecting a mixture of HFIP and alkanol into water. A stainless-steel needle was inserted into a piece of hollow fiber to prepare a magnetic bar. Then the magnetic bar was dipped in SUPRAS to impregnate the wall pores of the hollow fiber, followed by placing it into the serum sample for extraction. Only 4 μL of SUPRAS was consumed per bar. The MSB not only functioned for stirring, but also played the role of extraction and magnetic separation. Under the optimal extraction conditions (seven MSBs, extraction time 33 min and stirring rate 730 rpm), which was obtained by one variable-at-a-time and response surface methodology, the novel MSB-LPME was coupled with high performance liquid chromatography-tandem mass spectrometry to determine NSAIDs in human serum. The method showed a good linear relationship (correlation coefficients ≥ 0.9939). Method limits of detection and method limits of quantitation were in the range of 0.25-0.95 μg L^-1 and 0.83-3.16 μg L^-1, respectively. The recoveries for the spiked human serum samples ranged from 86.8% to 125.1% with intra- and inter-day relative standard deviations less than 9.2% and 18.1%, respectively. Moreover, the method did not require a protein precipitation step, and matrix effects of 72.8%-117.7% showed little interference with mass spectrometry detection, which was due to the double cleanup provided by the restricted access property of SUPRAS and the filtration capacity of hollow fiber. The HFIP-alkanol SUPRAS-based MSB-LPME method proved to be simple, highly efficient and environment-friendly for the pretreatment of serum/plasma.

Quick and Sensitive Enantioselective Determination of Permethrin in Fruits and Vegetables by Combining Supramolecular Solvents and Chiral Liquid Chromatography-Tandem Mass Spectrometry

Permethrin (PM) is one of the chiral insecticides most widely used around the world. The significant differential toxicity of its four enantiomers and its important adverse effects on human health highlights the need for determination of PM enantiomers. The aim of this work was to develop the first enantioselective method for quantification of PM in fruits and vegetables. The method is based on the extraction of PM enantiomers in supramolecular solvents with restricted access properties (SUPRAS-RAM) and their separation/detection by chiral liquid chromatography-tandem mass spectrometry (LC-MS/MS) which is first reported in this article. SUPRAS-RAM-based extraction is proposed as an innovative treatment approach that drastically reduces solvent consumption and avoids the need for sample cleanup. Extraction of PM enantiomers is quick (vortexing for 5 min) and efficient (recoveries 93-107%). The method is sensitive (quantification limits from 1.0 to 1.2 μg kg^-1) and suitable for control of PM enantiomers in agri-food products.

High throughput analysis of 21 perfluorinated compounds in drinking water, tap water, river water and plant effluent from southern China by supramolecular solvents-based microextraction coupled with HPLC-Orbitrap HRMS

The present work reported a high-throughput strategy for the analysis of 21 perfluorinated compounds (PFCs) in drinking water, tap water, river water and plant effluent from southern China by supramolecular solvent (SUPARS) vortex-mixed microextraction combined with high performance liquid chromatography-Orbitrap high resolution mass spectrometry (HPLC-Orbitrap HRMS). The SUPRAS without heating assistance is less solvent-consumption, meeting the requirements for green environmental protection and sustainable development. Parameters in the microextraction such as volume of dodecanol and tetrahydrofuran (THF), vortexing extraction and centrifugation time, salt concentration were investigated. The optimal extraction conditions were 250 μL of undecanol, 1.0 mL of THF and 20.0% (w/v, 4 g) NaCl. Under the optimum conditions, method limit of detection and method limit of quantitation in the ranges of 0.01-0.08 μg/L and 0.03-0.25 μg/L, good recoveries (72.5-117.8%) and intra-day precision (1.1-11.2%, n = 6), high enrichment factors (48-78) were obtained. The developed method was successfully applied for analysis of PFCs in 13 drinking water, tap water, river water and plant effluent samples collected from southern China. Perfluorobutane sulfonic acid was detected in one river water with concentration of 0.48 μg/L and 1H,1H,2H,2H-Perfluorooctane sulfonic acid was detected in one river water and two plant effluent samples with concentrations in the range of 0.14-0.67 μg/L.