The systematic consumption of food contaminated with antibiotics leads to emergence of resistant forms of microorganisms and also causes dysbiosis. Therefore, it is very important to ensure the ...necessary control of the residues of these contaminants in food by using fast and reliable methods. A simple and low-cost method for determining the trace content of amoxicillin in milk based on surface enhanced Raman spectroscopy (SERS) has been developed. To remove interfering components, a simple and fast "one-tube" method is proposed. Subsequent chromatographic purification makes it possible to almost completely eliminate the matrix effect of the sample, which ensures high accuracy and specificity of the SERS analysis. The conditions for chromatographic separation were selected to avoid the sorption of amoxicillin by free silanol groups of the stationary phase of the chromatographic column (C18), as well as to immediately carry out SERS analysis without intermediate steps. A calibration model was developed using the PLS chemometric algorithm, which further improved the accuracy and reproducibility of the analysis (R2 =0.9957 for the range 0.1–1.0 µM, RMSEC = 0.031 µM, RMSEP = 0.017 µM). This method allows to determine the content of amoxicillin in milk in the range of 1.1–11.0 µM and is characterized by good repeatability (RSD) ≤ 5.5% and a low limit of quantitation = 0.19 µM, which is considerably lower compared to the UV-HPLC method. Verification of the proposed method on samples of UHT (Ultra-High Temperature processed) milk of various fat content (1.8%, 2.5% and 3.2%) showed the recovery value = 100.6–105.7%.
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•Determination of amoxicillin in milk by HPLC-SERS.•Simple "one-tube" pre-purification method.•Effect of organic solvents on the SERS signal.•Controlled agglomeration of AgNPs using CaCl2.•Calibration using the PLS chemometric algorithm.
The Cytochrome P450 CYP1A2 is a central enzyme in the metabolism of drugs and xenobiotics. The overall activity of this enzyme is influenced by a complex array of biochemical, dietary, and genetic ...factors. One of the simplest ways to probe the overall output of CYP1A2 is to measure the ratio between the concentration of a precursor and a product of its activity. With the growing interest in the Paraxanthine/Caffeine ratio, the need arises to develop improved analytical methods specifically optimized for the rapid and sensitive determination of paraxanthine and caffeine in biological samples. We report a new optimized method for the determination of caffeine and paraxanthine in various human matrices. The method involved direct determination following protein precipitation based on ultra high performance liquid chromatographic separation with tandem mass spectrometric detection (UHPLC-ESIMS/MS). The method offers an improvement in the detection limit over previously published methods by at least 10-fold (0.1 pg), rapid chromatographic separation (ca. 5 min), the utilization of a green chromatographic solvent (5% v/v ethanol), direct determination with little sample preparation, and the employment of isotopically labeled internal standards and qualifier ions to ensure accuracy. Method validation in urine, saliva, and plasma was performed by spiking at various concentration levels where the recovery and repeatability were within ±15% and ±10%, respectively. The method was applied to investigate the levels of caffeine and paraxanthine in volunteers following controlled caffeine administration and to investigate the inter- and intra-individual variability in the paraxanthine/caffeine ratio in volunteers following an unrestricted caffeine diet. In conclusion, the developed UHPLC-ESIMS/MS method is optimized specifically for the simultaneous determination of the paraxanthine/caffeine ratio in multiple biological matrices, offers several advantages over the current methods, and is well suitable for application in large clinical studies.
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•LC-MS/MS method specifically optimized for the paraxanthine/caffeine ratio in various matrices.•Fast and green separation of major metabolites of caffeine in ca. 5 min.•An average of ca. 100-fold improvement in LOD (ca. 0.1 pg) over typically reported values (1–20 pg).•Application in 110 samples of saliva, urine, and plasma from two study groups.
This reprint features contributions from the conference DHA41. Dyes in History and Archaeology (DHA) is an annual international conference that focuses on the academic discussion of dyes and organic ...pigments which have been used in the past. Every year since 1982, this meeting has drawn together conservators; curators; (technical) art historians; craftspeople; artists; independent scholars; and scientists and academics from museums, universities, research centers, and other public or private institutions. Their common interest is to delve deeply into the history, production, application, and properties of organic colorants, as well as their analytical characterization and identification, often in textile objects, but also in other substrates as well as painted surfaces. In the autumn of 2022, the 41st DHA conference was hosted by the Swedish National Heritage Board in Visby. The abstracts are published on the DiVA portal (Digitala Vetenskapliga Arkivet), and many of the presented posters are available for download from the conference program. We are very grateful to the authors of the following 16 articles for submitting their manuscripts and allowing us to put together a publication that presents the fascinating breadth of research into Dyes in History and Archaeology.
Consumption of illicit drugs is a new concern for water management that must be considered not only because of the social and public health aspects but also in an environmental context in relation ...with the contamination of surface waters. Indeed, sewage treatment plant (STP) effluents contain drug residues that have not been eliminated since STP treatments are not completely efficient in their removal.
We developed and validated an HPLC–MS/MS analytical method to assess the concentrations of 17 illicit drugs and metabolites in raw urban wastewaters: cocaine and its metabolites, amphetamine and amphetamine-likes (methamphetamine, MDMA, MDEA, MDA), opiates and opiate substitutes (methadone and buprenorphine), and THC-COOH cannabis metabolite.
This method has been applied to the analysis of influent and effluent samples from 25 STPs located in France all over the country. The results allowed evaluating the drug consumption in the areas connected to the STPs and the efficiency of the treatment technology implied.
We selected STPs according to their volume capacity, their treatment technologies (biofilters, activated sludges, MBR) and their geographical location.
In influents, the concentrations varied between 6ng/L for EDDP (main metabolite of methadone) and 3050ng/L for benzoylecgonine (cocaine metabolite). Consumption maps were drawn for cocaine, MDMA, opiates, cannabis and amphetamine-like compounds. Geographical significant differences were observed and highlighted the fact that drug consumption inside a country is not homogeneous. In parallel, comparisons between STP technology processes showed differences of efficiency. More, some compounds appear very resistant to STP processes leading to the contamination of receiving water.
•Complete study with weekday and weekend samplings in 25 STPs in France.•Qualitative and quantitative differences in illicit drug consumption are observed.•LLAS treatments seem more efficient than MLAS treatments and biofilters.•Methadone and its metabolite EDDP appeared difficult to remove whatever the treatment.
Objective: Special, effective high pressure liquid chromatography method has been developed for the simultaneous quantification of Allantoin and Permethrin.
Methods: By using Waters HPLC e-2695 ...quaternary pump with a PDA detector of 2998 instrument the chromatographic separation of Allantoin and Permethrin was achieved on the column of Symmetry C18 (150x4.6 mm, 3.5 µm) using an isocratic elution with a buffer containing 0.1percent ortho phosphoric acid and acetonitrile at a rate of 40:60 as a mobile phase with a flow rate of 1 ml/min at ambient temperature. A detector wavelength of 226 nm utilizing the PDA detector were given in the instrumental settings. The linearity was studied between the concentration range of 1-15 µg/ml of Allantoin and 25-375 µg/ml of Permethrin were injected with a run time of 6 min. As a part of method validation the parameters like specificity, linearity, accuracy, ruggedness, robustness were determined and the results were found to be within the allowable limit. Validation of the proposed method was carried out according to an International Conference on Harmonization (ICH) guidelines.
Results: LOD and LOQ for the two active ingredients were established with respect to test concentration. The plotted calibration curves were linear with a regression coefficient of R2>0.999, indicates that the linearity was with in the limit. As a part of method validation the parameters like specificity, linearity, accuracy, ruggedness, robustness were determined and the results were found to be within the allowable limit.
Conclusion: The method developed was found to be applicable to routine analysis and to be used for the measurement of both active pharmaceutical ingredients (i. e, Allantoin and Permethrin). Since, there is no HPLC method reported in the literature for the estimation of Allantoin and Permethrin, there is a need to develop quantitative methods under different conditions to achieve improvement in specificity, selecivity etc.
Aflatoxins are mycotoxins that contaminate agricultural products when infected by toxigenic Aspergillus flavus. Methods for quantifying aflatoxin from culture using chromatography are available but ...are not optimized for population studies. We provide details of a method for preparation and quantitation of aflatoxin B1 from fungal cultures that satisfy those needs.
•Compounds identified from Gardenia jasminoides Ellis selected by chemometrics methods.•Compounds determined from Gardenia jasminoides Ellis were selected using PCA method.•Offer efficient means to ...carry out the establishment of fingerprints in TCM.
A fingerprint analysis method has been developed for characterization and discrimination of Gardenia jasminoides Ellis from different areas. The chemometrics methods including similarity evaluation, principal components analysis (PCA) and hierarchical clustering analysis (HCA) were introduced to identify more useful chemical markers for improving the quality control standard of dried ripe fruits of G. jasminoides Ellis. Then the selected chemical markers were analyzed by high performance liquid chromatography–diode array detection–electrospray ionization mass spectrometry (HPLC–DAD–ESI-MS) qualitatively and quantitatively. 23 characteristic peaks were assigned while 19 peaks of them were identified by comparing retention times, UV and MS spectra with authentic compounds or literature data. Moreover, 14 of them were determined quantitatively which could effectively evaluate the quality of G. jasminoides Ellis. This study was expected to provide comprehensive information for the quality evaluation of G. jasminoides Ellis, which would be a valuable reference for further study and development of this herb and related medicinal products.
•Lipophilicity of a small library of bioactive xanthone derivatives was evaluated.•Different computational and experimental methods were chosen.•VALLME-HPLC, RP-HPTLC, RP-HPLC and biomembranes model ...were used.•Results obtained by all methods were compared and discussed.
For the last several years, searching of new xanthone derivatives (XDs) with potential pharmacological activities has remained one of the main areas of interest of our group. The optimization of biological activity and drug-like properties of hits and leads is crucial at early stage of the drug discovery pipeline. Lipophilicity is one of the most important drug-like properties having a great impact in both pharmacokinetics and pharmacodynamics processes. In this work, we describe the lipophilicity of a small library of bioactive XDs, previously synthesized by our group, using different methods: computational, vortex-assisted liquid–liquid microextraction coupled with high-performance liquid chromatography (VALLME-HPLC), reversed-phase high-performance thin layer chromatography (RP-HPTLC), reversed-phase high-performance liquid chromatography (RP-HPLC), and biomembrane model by the partition between micelles and aqueous phase. The different results obtained by the used methods were compared and discussed. The methodologies and data gathered in this study will expand the investigation of lipophilicity of XDs, an important class of compounds in medicinal chemistry.
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