Simultaneous determination of 11 illicit drugs and metabolites in wastewater by UPLC-MS/MS

Direct injection ultra-performance liquid chromatography-tandem mass spectrometry for the high-throughput determination of etomidate and etomidate acid in wastewater

Etomidate (ET), a hypnotic agent used for the induction of anesthesia, is rapidly metabolized to etomidate acid (ETA) in the liver. Recently, ET has become one of the most serious alternative drugs of abuse in China. Therefore, an urgent need exists to develop a fast and convenient analysis method for monitoring ET. The current work presents a simple, fast, and sensitive direct injection method for the determination of ET and ETA in wastewater. After the optimization of the ultra-performance liquid chromatography-tandem mass spectrometry and sample filtration conditions, the method exhibited satisfactory limits of detection (1 ng/L) and good filtration loss. The validated method was successfully applied to determine the concentrations of ET and ETA in wastewater samples (n = 245) from several wastewater treatment plants in China. The concentrations of the targets in positive samples ranged from less than the lower limits of quantitation to 47.71 ng/L. The method can meet ET monitoring and high-throughput analysis requirements.

Trends and challenges in analytical chemistry for multi-analysis of illicit drugs employing wastewater-based epidemiology

Wastewater-based epidemiology (WBE) for quantification of illicit drug biomarkers (IDBs) in wastewater samples is an effective tool that can provide information about drug consumption. The most commonly quantified IDBs belong to different chemical classes, including cocaine, amphetamine-type stimulants, opioids, and cannabinoids, so the different chemical properties of these molecules pose a challenge in the development of analytical methods for multi-analyte analysis. Recent workflows include the steps of sampling and storage, sample preparation using solid-phase extraction (SPE) or without extraction, and quantification of analytes employing gas or liquid chromatography coupled with mass spectrometry. The greatest difficulty is due to the fact that wastewater samples are complex chemical mixtures containing analytes with different chemical properties, often present at low concentrations. Therefore, in the development of analytical methods, there is the need to simplify and optimize the analytical workflows, reducing associated uncertainties, analysis times, and costs. The present work provides a critical bibliographic survey of studies published from the year 2020 until now, highlighting the challenges and trends of published analytical workflows for the multi-analysis of IDBs in wastewater samples, considering sampling and sample preparation, method validation, and analytical techniques.

UPLC Technique in Pharmacy—An Important Tool of the Modern Analyst

In recent years, ultra-efficient liquid chromatography (UPLC) has gained particular popularity due to the possibility of faster separation of small molecules. This technique, used to separate the ingredients present in multi-component mixtures, has found application in many fields, such as chemistry, pharmacy, food, and biochemistry. It is an important tool in both research and production. UPLC created new possibilities for analytical separation without reducing the quality of the obtained results. This technique is therefore a milestone in liquid chromatography. Thanks to the increased resolution, new analytical procedures, in many cases, based on existing methods, are being developed, eliminating the need for re-analysis. Researchers are trying to modify and transfer the analytical conditions from the commonly used HPLC method to UPLC. This topic may be of strategic importance in the analysis of medicinal substances. The information contained in this manuscript indicates the importance of the UPLC technique in drug analysis. The information gathered highlights the importance of selecting the appropriate drug control tools. We focused on drugs commonly used in medicine that belong to various pharmacological groups. Rational prescribing based on clinical pharmacology is essential if the right drug is to be administered to the right patient at the right time. The presented data is to assist the analyst in the field of broadly understood quality control, which is very important, especially for human health and treatment. This manuscript shows that the UPLC technique is now an increasingly used tool for assessing the quality of drugs and determining the identity and content of active substances. It also allows the monitoring of active substances and finished products during their processing and storage.

Competitive fluorescence immunoassay for the rapid qualitative screening and accurate quantitative analysis of ketamine

In this paper, a sensitive and specific competitive fluorescence immunoassay (CFIA) method was developed for the qualitative and quantitative analysis of ketamine (KET). A novel competitive model in which ketamine hapten (KET-BSA), coated on microporous plates, competed with ketamine antigen (KET-Ag) in actual samples to bind fluorescein isothiocyanate-labeled antibody (KET-Ab) could be used for rapid and indirect quantitative analysis of KET in human urine, blood, or sewage. In the CFIA method, KET concentration in the sample negatively correlated with the detected fluorescence intensity. The linear correlation coefficient of the competitive quantitative equation was 0.992, the linear range was 0.01-0.5 μg mL^-1, and the limit of detection (LOD) was 0.1 pg mL^-1. The specificity results showed that the cross-reaction rate of norketamine was less than 10%. Recoveries of spiked samples at low, medium, and high concentrations ranged from 96% to 117%. The CFIA method and classical gas chromatography-tandem mass spectrometry (GC-MS/MS) were used to detect the actual samples simultaneously. The relative deviation of the quantitative results was less than 10%. The LOD value of KET by CFIA was four orders of magnitude lower than that by GC-MS/MS. Additionally, CFIA had great advantages over GC-MS/MS in terms of sample pretreatment and economic investment. In conclusion, this study provided a targeting detection platform for KET, which achieved a rapid, portable, and sensitive analysis of trace KET in various materials.

Preparation and application of nano petal-shaped covalent organic frameworks modified polystyrene-divinylbenzene- glycidylmethacrylate microspheres for the extraction of illicit drugs from wastewater

A novel nano petal-shaped covalent organic frameworks modified magnetic polystyrene-divinylbenzene-glycidylmethacrylate (NP-COF@Mag-PS/DVB/GMA) microsphere has been synthesized. It is a perfect combination of high productivity of PS/DVB/GMA microspheres and excellent enrichment efficiency of COF particles, and the excellent properties of NP-COF@Mag-PS/DVB/GMA microspheres are characterized by scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) and X-ray photoelectron spectroscopy (XPS). The sorbent can extract illicit drugs via the reverse-phase interactions provided by benzene ring on the polymer backbone and the hydrogen bonding interactions provided by functional group (-NH-) on the COF particles. Based on using NP-COF@Mag-PS/DVB/GMA as sorbents, an easiness-to-handle of magnetic dispersive solid phase extraction (Mag-dSPE) procedure is proposed for the simultaneous preconcentration of 12 illicit drugs from wastewater. The obtained results show high extraction efficiency of NP-COF@Mag-PS/DVB/GMA to illicit drugs with recoveries between 81.6 and 116%. Furthermore, a liquid chromatography-tandem quadrupole mass spectrometry (LC-MS/MS) method for the determination of 12 illicit drugs from wastewater at sub-ppt levels has been proposed and validated with the pretreatment of samples by Mag-dSPE. The limits of quantification (LOQs) for the 12 illicit drugs are between 0.40 and 4.90 ng/L. Validation results on linearity, specificity, trueness and precision, as well as on application to the analysis of 12 illicit drugs in ten real samples demonstrate the applicability to environment monitoring analysis.