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The number of cases in which scopolamine (SCO) was used for both recreational and predatory purposes has increased dramatically in recent decades. Linked to this, there is a concern about obtaining SCO through thermal degradation of butylscopolamine (BSCO) - an active ingredient of Buscopan® - a drug sold without a medical prescription. In this study, mixtures containing SCO and BSCO were separated and detected on a microchip electrophoresis (ME) device with integrated capacitively coupled contactless conductivity detection (C 4 D) using a running buffer composed of 40 mmol L -1 of butyric acid and 25 mmol L -1 of sodium hydroxide (pH 5.0). The separation was performed within ca. 115 s with a resolution of 1.3 and separation efficiency ranging from 1.4 × 10 5 to 1.5 × 10 5 theoretical plates m -1 . A detection limit of 1.1 μmol L -1 was achieved for both species and the developed method revealed satisfactory repeatability with relative standard deviation (RSD) values for forty-eight injections between 4.8 and 9.4% for peak areas and lower than 3.3% for migration times. Furthermore, inter-day precision was evaluated for sixteen injections (a sequence of four injections performed over four days), and RSD values were less than 6.6% for peak areas and 2.2% for migration times. Satisfactory recovery values (95-114%) were obtained for all evaluated beverage samples (cachaça, vodka, whiskey, beer, Coca-Cola, and grape juice) as well as for artificial urine samples (95-107%). Finally, the conversion of BSCO into SCO was observed after simple heating procedure of Buscopan® sample (not subject to medical prescription), which was successfully confirmed through analysis by capillary electrophoresis coupled to the mass spectrometry (CE-MS). Based on the reported results, the use of ME-C 4 D devices has demonstrated a huge potential for applications in the forensic chemistry field., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Whisky adulteration is a prevalent practice driven by the high cost of these beverages. Counterfeiters commonly dilute whisky with less expensive alcoholic beverages, water, food additives, drugs or pharmaceuticals. Paracetamol (PAR), an analgesic drug that mitigates hangovers and headaches, is commonly used to adulterate whisky. Currently, the primary method for quantifying PAR levels is high-performance liquid chromatography, but this technique is both time consuming and usually generates more residues. In this context, the utilization of miniaturized and portable analytical devices becomes imperative for conducting point-of-care/need analyses. These devices offer several advantages, including portability, user-friendliness, low cost, and minimal material wastage. This study proposes the selective distance-based PAR quantification on whisky samples using a paper-based microfluidic analytical device (μPAD). Colorimetric detection on paper-based platforms offers great benefits such as affordability, portability, and the ability to detect PAR without complicated instrumentation. The optimal detection conditions were achieved by introducing 5 μL of a mixture containing 7.5 mmol L -1 of Fe(III) and K 3 [Fe(CN) 6 ] into the detection zone, along with 12 μL of whisky samples into the sample zone. The method exhibited linear behavior within the concentration range from 15 to 120 mg L -1 , with a determination coefficient of 0.998. PAR was quantified in adulterated samples. The results obtained with the paper-based devices were compared with a referenced method, and no significant differences were observed at a confidence level of 95%. The μPAD allowed to determine ca. 1 drop of pharmaceutical medicine PAR of 200 mg mL -1 in 1 L of solution, demonstrating excellent sensitivity. This method offers cost-effective and rapid analysis, reducing the consumption of samples, reagents, and wastes. Consequently, it could be considered a viable and portable alternative for analyzing beverages at criminal scenes, customs, and police operations, thereby enhancing the field of forensics.

A capillary electrophoresis-mass spectrometry method was used to analyze naphthenic acids in produced water samples. It was possible to detect cyclopentanecarboxylic, benzoic, cyclohexanebutyric, 1-naphthoic, decanoic, 3,5-dimethyladamantane-1-carboxylic, 9-anthracenecarboxylic, and pentadecanoic acids within ca. 13 min using a buffer composed of 40 mmol/L ammonium hydroxide, 32 mmol/L acetic acid and 20% v/v isopropyl alcohol, pH 8.6. The proposed method showed good repeatability, with relative standard deviation (RSD) values of 6.6% for the sum of the peak areas and less than 2% for the analysis time. In the interday analysis, the RSD values for the sum of the peak areas and migration time were 10.3% and 10%, respectively. The developed method demonstrated linear behavior in the concentration range between 5 and 50 mg/L for benzoic, decanoic, 3,5-dimethyladamantane-1-carboxylic and 9-anthracenecarboxylic acids, and between 10 and 50 mg/L for cyclopentanecarboxylic, cyclohexanebutyric, 1- naphthoic, and pentadecanoic acids. The detection limits values ranged from 0.31 to 1.64 mg/L. Six produced water samples were analyzed and it was possible to identify and quantify cyclopentanecarboxylic, benzoic, cyclohexanebutyric, and decanoic acids. The concentrations varied between 4.8 and 98.9 mg/L, proving effective in the application of complex samples., (© 2023 Wiley-VCH GmbH.)

Neglected tropical diseases (NTDs) affect tropical and subtropical countries and are caused by viruses, bacteria, protozoa, and helminths. These kinds of diseases spread quickly due to the tropical climate and limited access to clean water, sanitation, and health care, which make exposed people more vulnerable. NTDs are reported to be difficult and inefficient to diagnose. As mentioned, most NTDs occur in countries that are socially vulnerable, and the lack of resources and access to modern laboratories and equipment intensify the difficulty of diagnosis and treatment, leading to an increase in the mortality rate. Portable and low-cost microfluidic systems have been widely applied for clinical diagnosis, offering a promising alternative that can meet the needs for fast, affordable, and reliable diagnostic tests in developing countries. This review provides a critical overview of microfluidic devices that have been reported in the literature for the detection of the most common NTDs over the past 5 years.

This study reports for the first time the use of a microchip electrophoresis (ME) device with integrated capacitively coupled contactless conductivity detection (C 4 D) to analyze naphthenic acids in produced water. A mixture containing 9-anthracenecarboxylic, 1-naphthoic, and benzoic acids was separated and detected using a running buffer composed of 10 mmol L -1 carbonate buffer (pH = 10.2). The separation was achieved within ca. 140 s with baseline resolution greater than 2 and efficiency values ranging from 1.9 × 10 5 to 2.4 × 10 5 plates m -1 . The developed methodology provided linear correlation with determination coefficients greater than 0.992 for the concentration ranges between 50 and 250 µmol L -1 for benzoic and 9-anthracenecarboxylic acids, and between 50 and 200 µmol L -1 for 1-naphthoic acid. The achieved limit of detection values varied between 4.7 and 7.7 µmol L -1 . The proposed methodology revealed satisfactory repeatability with RSD values for a sequence of eight injections between 5.5 and 7.7% for peak areas and lower than 1% for migration times. In addition, inter-day precision was evaluated for sixteen injections (a sequence of four injections performed during four days), and the RSD values were lower than 11.5 and 4.9% for peak areas and migration time, respectively. Five produced water samples were analyzed, and it was possible to detect and quantify 9-anthracenecarboxylic acid. The concentrations ranged from 1.05 to 2.24 mmol L -1 with recovery values between 90.8 and 96.0%. ME-C 4 D demonstrated satisfactory analytical performance for determining naphthenic acids in produced water for the first time, which is useful for petroleum or oil industry investigation., Competing Interests: Declaration of Competing Interest The authors declare no conflict of interest., (Copyright © 2022 Elsevier B.V. All rights reserved.)

This report describes the use of electrophoresis microchips integrated with contactless conductivity detection for the determination of organic acids and inorganic anions in wine samples and the subsequent classification based on the grape varieties. The best separation was achieved using a buffer composed of 30 mmol L -1 2-(N-morpholino)ethanesulfonic acid, 15 mmol L -1 l-histidine and 0.05 mmol L -1 cetyltrimethylammonium bromide (pH 5.8), allowing the determination of chloride, nitrate, sulfate, oxalate, tartrate, maleate, succinate, citrate, acetate, lactate, pyroglutamate and phosphate within ca. 100 s. The relative standard deviations obtained for the migration times were lower than 2%, while the obtained values for peak areas ranged from 2.5 to 8.4%. The limits of detection achieved for all compounds ranged between 3.0 and 12.6 μmol L -1 . A total of 18 wines from Brazil and Chile were successfully investigated, including red, white and rosé, and the anionic species were quantified with recovery values between 92 and 117%. A statistical difference has not been observed between the data obtained by using electrophoresis microchips integrated with contactless conductivity detection (ME-C 4 D) and capillary electrophoresis with ultra-violet detection (CE-UV) and thus the results from newly developed method is validated. Finally, similarities among the anionic profile of wines were investigated by using a multivariate approach, and it was possible to discriminate samples mainly by grapes varieties. Furthermore, the proposed methodology has provided instrumental simplicity and good analytical performance, demonstrating to be useful for routine quality control of wines., (Copyright © 2021 Elsevier B.V. All rights reserved.)

This study describes the development of an analytical methodology based on the use of microchip electrophoresis (ME) devices integrated with capacitively coupled contactless conductivity detection (C 4 D) for the separation and detection of inorganic anions in post-blast explosive residues. The best separation condition was achieved using a running buffer composed of 35 mmol/L lactic acid, 10 mmol/L histidine and 0.070 mmol/L cetyl(trimethyl ammonium) bromide. For C 4 D measurements, the highest sensitivity was obtained applying a 700 kHz sinusoidal wave with excitation voltage of 20 V pp . The separation of Cl - , NO 3 - , NO 2 - , SO 4 2- , ClO 4 - and ClO 3 - was performed within ca. 150 s with baseline resolution and efficiencies between 4.4 × 10 4 and 1.7 × 10 5 plates/m. The found limits of detection ranged between 2.5 and 9.5 μmol/L. Last, real samples of post-blast explosive residues were analyzed on the ME-C 4 D devices obtaining successfully the determination of Cl - , NO 3 - and SO 4 2- . The achieved concentration values varied between 12.8-72.5 mg/L for Cl - , 1.7-293.1 mg/L for NO 3 - and 1.3-201.3 mg/L for SO 4 2- . The data obtained using ME-C 4 D devices were in good agreement with the concentrations found by ion chromatography. The approach reported herein has provided short analysis time, instrumental simplicity, good analytical performance and low cost. Furthermore, the ME-C 4 D devices emerge as a powerful and portable analytical platform for on-site analysis demonstrating to be a promising tool for the crime scene investigation., (© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)