Analytical and Bioanalytical Chemistry最新文献

Dried urine spots have recently been proposed as an alternative matrix in the anti-doping field. Drying urine may open the opportunity to limit microbial and thermal degradation of the prohibited substances during transportation to the anti-doping laboratories without the need for refrigeration or freezing. In this study, a multi-targeted initial testing procedure was developed for the determination of 237 prohibited drugs/metabolites from 11 different classes in dried urine spots. The comparability between two different microsampling techniques (i.e., Whatman^® FTA DMPK-C cards and Mitra^® tips) was evaluated. The developed method was then used to evaluate the stability of the target compounds in urine for 7 days under different environmental conditions to simulate the transportation of the urine samples from the collection sites to anti-doping laboratories. Sample preparation consists of (i) extraction of the analytes from the collection device using a mixture of acetonitrile/methanol (1/1) for 30 min at 40 °C, (ii) enzymatic hydrolysis, and (iii) sample concentration by solid-phase extraction. Analysis was performed using liquid chromatography coupled to high-resolution mass spectrometry. The entire workflow was validated in terms of specificity (analytes were distinguishable from the matrix interferences), sensitivity (only with the Mitra^® tips the limits of detection comply with the World Anti-Doping Agency's requirements for the majority of the target compounds), carry-over (no signals in the negative urine injected after the positive urine), matrix effect (16-28% for Mitra^® tips and 22-35% for DMPK-C cards), and extraction yield (Mitra^® tips: 51-88%; DMPK-C cards: 40-76%). As proof of concept, authentic urine samples were analyzed: results obtained in dried urine were compared with those of fluid urine, providing good agreement. Stability studies showed that the target compounds were stable for the whole duration of the study (7 days) at -20 and 4 °C in both fluid and dried urine. At 50 °C or at 20-25 °C, several thiazide-based compounds were completely degraded to their degradation product in the first 24 h or after 3-4 days in fluid urine, whereas in dried urine the compounds were detectable for the entire duration of the study.

Aquaphotomics is an approach that describes the water-light interactions in aqueous solutions or biological systems and retrieves information about the nature of the underlying water-related interactions. We evaluated the water spectral pattern (WASP) and water matrix structure of freshly harvested cannabis inflorescence from seven different chemovars using near-infrared (NIR) spectral data coupled with chemometric models. Six activated water bands-1342, 1364, 1384, 1412, 1440, and 1462 nm, occurred consistently in all of the spectrum exploration steps as well as in the partial least squares-discriminant analysis (PLS-DA) steps. However, according to major class and chemovar aquagram values, the largest spectral variation was associated with the following bands: 1412, 1364, 1374, 1384, 1488, and 1512 nm. A strong positive correlation between 1364, 1374, and 1384 nm aquagram values and a strong negative correlation between 1412 and 1512 nm aquagram values were observed through all aquagram analysis steps. These water activated bands were found to serve as good discriminators and classifiers according to either major class or chemovar. Furthermore, significant differences in the water matrix structure of different cannabis chemovars were observed, with the highest variations associated with the presence of free water molecules, small molecule solvation shells, extent of strongly bound water, and the number of hydrogen bonds per water molecule. Minor cannabinoids and terpenes such as cannabigerolic acid and (-)-guaiol displayed relatively high correlations with these bands. The results of this study suggest that the most accurate way to explore the cannabis inflorescence water matrix spectral pattern is by chemovars and not by major classes.

Determination of free cyanide (fCN) is required for various industrial, environmental, food, and clinical samples. Enzymatic methods are not widely used in this field despite their selectivity and mild conditions. Therefore, we present here a proof of concept for new spectrophotometric enzymatic assays of fCN. These are based on the hydrolysis of fCN affording the readily detectable NADH. fCN is hydrolyzed either in one step by cyanide dihydratase (CynD) or in two steps by cyanide hydratase (CynH) and formamidase (AmiF). An advantage of the latter route is the higher activity of CynH and AmiF compared to CynD. In both cases, the resulting formate is then transformed by an NAD-dependent formate dehydrogenase (FDH). The NADH thus formed is quantified colorimetrically using a known method based on a reduction of a tetrazolium salt (WST-8) with NADH. The developed assays of fCN are selective except for formic acid interference, proceed under mild conditions, and, moreover, fCN is detoxified during the reactions. The assays proceeded in a microtiter plate format. The limit of detection (LOD) and the limit of quantification (LOQ) were lower for the three-enzyme (CynH-AmiF-FDH) method (7.00 and 21.2 µmol/L, respectively) than for the two-enzyme (CynD-FDH) method (10.7 and 32.4 µmol/L, respectively). In conclusion, the new fCN assays presented in this work are selective, high-throughput, do not require harsh conditions, and use only small amounts of chemicals and enzymes.

Pronase-catalyzed proteolysis is shown to produce single amino acid adducts of tyrosine (Tyr) and cysteine (Cys) obtained from both human serum albumin (HSA) and immunoglobulin G (IgG) after in vitro exposure of plasma to the nerve agent VX. Total plasma as well as isolated HSA and IgG yielded the Tyr residue phosphonylated with the ethyl methylphosphonic acid moiety, Tyr(-EMP). Furthermore, a Cys residue adducted with the diisopropylaminoethane thiol leaving group of the agent bound via a disulfide bridge, Cys(-DPAET), was also obtained from both proteins. Even though Tyr(-EMP) represents an internationally well-accepted biomarker of a VX-like agent its origin from plasma IgG has never been shown before. In addition, this is the first time that Cys(-DPAET) is presented as a biomarker of VX exposure clearly identifying the chemical nature of the V-type nerve agent's leaving group. Both biomarkers were detected after selective affinity-based solid-phase extraction (SPE) from plasma that yielded highly purified HSA and IgG as documented by sodium dodecyl polyamide gel electrophoresis (SDS-PAGE). Both biomarkers were found in the corresponding protein bands of HSA and IgG each after in-gel proteolysis with pronase. A micro liquid chromatography-electrospray ionization high-resolution tandem-mass spectrometry method (LC-ESI HR-MS/MS) was developed for the simultaneous detection of Tyr(-EMP) and Cys(-DPAET). The time for proteolysis was optimized for maximum biomarker yield. The method showed excellent selectivity and sensitivity, and the adducted proteins and biomarkers were found to be highly stable during storage. Accordingly, the presented method sheds more light on the molecular toxicology of VX and broadens the spectrum of methods suited for biomedical verification.

Simultaneous removal and identification of trace-level cationic dye pollutants from water is both important and challenging owing to their highly polar and complex sample matrices. In this study, three covalent organic frameworks (COFs) were synthesized using 2, 4, 6-triformylphloroglucinol with ethidium bromide (EB) containing positively charged groups, 3, 5-diaminobenzoic acid (DABA) containing negatively charged groups, and p-phenylenediamine (Pa) lacking charged groups. These were named EB-COFs, TpPa-1, and DP-COFs, respectively, and were employed as adsorbents for the extraction and identification of cationic dyes. The adsorption performance of the three COFs toward methylene blue (MB) and crystal violet (CV) was investigated. By incorporating carboxyl groups into DP-COFs, the surface chemistry of the adsorbent was effectively tailored, enabling complete exploitation of selective cationic sites. This facilitated dynamic interactions with cationic dyes through multiple adsorption mechanisms, including electrostatic, π-π, and H-bonding interactions. DP-COFs exhibited high adsorption capacities for MB and CV, achieving 383 and 326 mg g^-1, respectively. The adsorption behavior was further analyzed using adsorption isothermals, kinetics, and thermodynamics. Moreover, DP-COFs were employed as a matrix in laser desorption/ionization time-of-flight mass spectrometry (LDI-TOF MS) to adsorb and directly identify both cationic dyes without the need for an elution process. This approach demonstrated high sensitivity, high reproducibility, low background interference, and excellent salt tolerance. The limits of detection for MB and CV were 0.12 and 0.04 ng mL^-1, respectively, representing improvements of 166-fold and 225-fold compared with using DP-COFs solely as a matrix. Recovery rates of both dyes in spiked industrial wastewater and lake water samples ranged from 81.4 to111.1% with RSDs of 1.9-6.3%. These results highlight the high reliability of the proposed method.

Bruton's tyrosine kinase inhibitors (BTKis) exhibit significant interindividual pharmacokinetics, making therapeutic drug monitoring (TDM) a promising approach for personalized therapy. However, simultaneous quantification of multiple BTKis poses technical challenges. A unified protocol for BTKis detection would be clinically desirable. Herein, we developed and validated a novel LC-MS/MS method for the simultaneous analysis of four BTKis including ibrutinib (IBR), zanubrutinib (ZAN), orelabrutinib (ORE), and acalabrutinib (ACB) and active metabolite of IBR and ACB (DIH and ACBM, respectively) in human plasma. The samples were prepared by liquid-liquid extraction using tert-butyl methyl ether. Ibrutinb-d4 (IS) was used as an internal standard. Chromatographic separation was obtained on an XBridge C18 column and connected to an LC-30AD system coupled to an API 4000⁺ mass spectrometer. The mobile phase comprised 10 mM ammonium acetate containing 0.1% formic acid and acetonitrile containing 0.1% formic acid. The optimized multiple reaction monitoring transitions of m/z 441.4 → 138.3, 475.4 → 304.2, 472.5 → 455.5, 428.3 → 411.5, 466.1 → 372.2, 482.2 → 388.4, and 445.5 → 142.5 were selected to inspect IBR, DIH, ZAN, ORE, ACB, ACBM, and IS, respectively. The method exhibited linearity from 1 to 1000 ng/mL (r > 0.99) for all analytes, with intra-day and inter-day precision of 1.8 to 9.7% and accuracy below 15%. Recovery ranged from 90.4 to 113.6%, and matrix effect varied from 89.3 to 111.0%. All compounds demonstrated stability under relevant conditions. Application of the method to 57 blood samples from 18 patients demonstrated high interpatient variability, with ORE plasma concentrations ranging from 25.6 to 89.9%. The validated LC-MS/MS method provides a feasible, specific, and rapid approach for quantification of BTKis in clinical settings. Simultaneous determination of four BTKis and their metabolites in a single extraction process and chromatographic run reduces analysis time, cost, and resources. The observed variability among individuals highlights the value of TDM for personalized treatment.

Despite their diffusion in research studies, passive samplers are rarely used in regulatory applications. To expand the employment of passive samplers in regulatory environmental studies, standardized procedures for processing each sampler type should be proposed and accepted, but currently, each study develops its own protocol based on previous knowledge and specific needs. In this work, six identical polar organic chemical integrative samplers in seawater were deployed to understand the importance of the sorbent transfer method prior to the elution step. A common "wet transfer" with ultra-pure water was compared to a less diffused "dry-transfer," assessing recoveries and matrix effects of 38 target compounds of emerging concern, including polar pesticides, recreational and food-related substances, pharmaceuticals, industrial additives, and ultra-violet (UV) filters. The dry-transfer procedure generally allowed better recoveries, especially for the more polar compounds, without affecting matrix effects (which remained in the range 40-130%). Along with the recovery assessment, the analysis of the non-spiked sorbent extracts revealed traces of many of the targeted emerging contaminants, quantifying perfluorooctanoic acid, UV-filters, carbamazepine, diclofenac, and triclosan. Furthermore, other compounds were found below their limits of quantitation. Ten analytes were detected only in the extracts of the dry-transferred passive samplers, highlighting the importance of applying this protocol, especially when dealing with polar compounds. This refined processing method, therefore, permits a more standardized and reproducible strategy, at the same time enlarging the set of analytes which could be detected and quantified.

The wide range of mass spectrometry imaging (MSI) technologies enables the spatial distributions of many analyte classes to be investigated. However, as each approach is best suited to certain analytes, combinations of different MSI techniques are increasingly being explored to obtain more chemical information from a sample. In many cases, performing a sequential analysis of the same tissue section is ideal to enable a direct correlation of multimodal data. In this work, we explored different workflows that allow sequential lipid and elemental imaging on the same tissue section using atmospheric pressure laser desorption/ionisation-plasma post-ionisation-MSI (AP-MALDI-PPI-MSI) and laser ablation-inductively coupled plasma-MSI (LA-ICP-MSI), respectively. It is found that performing lipid imaging first using matrix-coated samples, followed by elemental imaging on matrix-coated samples, provides high-quality MSI datasets for both lipids and elements, with the resulting distributions being similar to those obtained when each is performed in isolation. The effect of matrix removal prior to elemental imaging, and of performing elemental imaging first were also investigated but found to generally yield lower quality elemental imaging data but comparable lipid imaging data. Finally, we used the ability to acquire both elemental and lipid imaging data from the same section to investigate the spatial correlations between different lipids (including ceramides, phosphatidylethanolamine, and hexosylceramides) and elements within mouse brain tissue.

Bisphenols, as a new class of environmental endocrine disruptors (EED), can interfere with the endocrine system of the human body and lead to various diseases. In this study, a novel polyaniline functionalized metal-organic framework (PANI@MIL-101@HF) was synthesized by utilizing hollow fibers (HF) as the the immobilization carrier, and combined with methyl tert-butyl ether (MTBE) for solid-liquid cooperative adsorption to determine bisphenols (BPs) in serum samples. The immobilized adsorbent exhibited excellent high stability and hydrophobicity. Furthermore, the inclusion of amino and benzene rings in PANI enhanced the adsorption efficiency of BPs through π-π and hydrogen bond interactions. Surprisingly, owing to the synergies of size exclusion effect of the MIL-101 and HF, the exclusion rate of protein reached as high as 99.2-99.9%. Based on its excellent adsorption properties and protein exclusion effect, the immobilized adsorbent PANI@MIL-101@HF was successfully used as a new restricted material for the high extraction performance with solid-liquid synergy of nine bisphenols (BPs) in serum samples. The operation process has also become more convenient without centrifuging. Integrated with ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS), the nine BPs in serum samples have a wide linear range (2-200 ng mL^-1) with low quantitative limits of 0.02 ng mL^-1, and the recoveries ranged from 84.65 to 112.56%. The proposed method could be widely applied in convenient, green, and sensitive detection of endocrine disruptors from serum samples.