The presence of emerging contaminants (ECs) is a cause of great concern nowadays, and they are present at very low concentrations in surface waters, requiring a preconcentration process for their reliable quantification. The technique of Stir-Bar Sorptive Extraction (SBSE) is a valuable tool for achieving this purpose, and different sorbents have been developed to produce the bars. In this sense, we propose the use of the clay mineral vermiculite (Vt), modified with alkylammonium salts, aiming the determination of the ECs: bisphenol A, diclofenac, ibuprofen and triclosan in surface water samples.

The best conditions for sorption and desorption were: 50.0 mL of sample at pH 4.0, under stirring at 600 rpm (120 min), being the desorption carried out under sonication for 20 min using 500 μL of methanol, and the analytes were determined using LC-DAD. A linear range from 0.50 to 2.50 μg L-1 or from 0.50 to 5.00 μg L-1 and R2 higher than 0.9480 were observed, and attractive real enrichment factors between 116 and 177 times, affording a LOD between 0.11 and 0.33 μg L-1. The method was applied to determine the four ECs in samples of tap, river, and lake waters, presenting recovery results between 42.0 and 128.0 %, and RSD from 0.4 to 19.6 %. The bars prepared using Vt presented good chemical and mechanical resistance, even modified using the alkylammonium salts, permitting them to be employed at least 30 times, without memory effects.

The modified Vt, afforded a simple, low-cost, and attractive alternative to work as a sorbent phase for SBSE technique, presenting very appropriate analytical parameters, even employing LC-DAD. Although the sorbent was applied to a limited number of contaminants, it is probable that other analytes could be successfully determined. It is important to notice that this is the first study reported, employing modified Vt for SBSE application.

In this work, a novel 3D μPAD cellulose-based colorimetric chemosensor for multiplexed detection of paracetamol and aspirin in biological samples is proposed. The easy availability of analgesics such as paracetamol and non-steroidal anti-inflammatory drugs such as aspirin, over-the-counter drugs that can be acquired without medical prescription, can entail a health problem if they are administered incorrectly. The development of analytical procedures for the rapid, sensitive, and accurate determination of such drugs in clinical samples is of utmost importance. Different parameters involved in the design of the 3D μPAD system and the colorimetric reaction conditions have been optimized. Under optimal conditions, detection limits of 0.004 mM and 0.013 mM were obtained for paracetamol and aspirin, respectively. The proposed procedure was validated against two certified reference materials and applied to the analysis of several synthetic urine and saliva samples. Synthetic urine and saliva samples were spiked at two concentration levels, showing recoveries in the range of 98-103% with a relative standard deviation of 3-6% (n = 6).

Two simple, valid and green chromatographic based techniques are developed in the present work for first time to simultaneously analyze the recently approved combination of Aspirin (ASP) with the novel gastro-protective agent Vonoprazan (VON). First method is an HPLC-DAD "diode array detection", where separation was successful using C18 (250 × 4.6 mm) column with isocratic elution of phosphate buffer-pH 6.8 and acetonitrile in ratio of 63:37 with detection at 230 nm. Second method is an HPTLC method on HPTLC silica plates using ethyl acetate: ethanol (75%): ammonia (5:5:0.05 v/v) mobile phase followed by densitometric scanning at 230 nm. The methods were applied successfully for analysis of VON and ASP mixture in laboratory-prepared tablets and the methods were validated in regards to linearity, precision, accuracy and selectivity. The proposed methods are assessed for their greenness and whiteness as well using the "Analytical GREEnness Metric Approach", "Complementary Modified Green Analytical Procedure Index" and the new algorithm "RGB 12 model" (Red-Green-Blue) and proved the greenness and the sustainability of the methods in the routine assay of the newly marketed formulation.

Separation analytical methods, including liquid chromatography (LC) and capillary electrophoresis (CE), in combination with an appropriate detection technique, are dominant and powerful approaches preferred in the analysis of pharmaceutical and biomedical samples. Recent trends in analytical methods are focused on activities that push them to the field of greenness and sustainability. New approaches based on the implementation of greener solvents, non-hazardous chemicals, and reagents have grown exponentially. Similarly, recent trends are pushed in to the strategies based on miniaturization, reduction of wastes, avoiding derivatization procedures, or reduction of energy consumption. However, the real greenness of the analytical method can be evaluated only according to an objective and sufficient metric offering complex results taking into account all twelve rules of green analytical chemistry (SIGNIFICANCE mnemonic system). This review provides an extensive overview of papers published in the area of development of green LC and CE methods in the field of pharmaceutical and biomedical analysis over the last 5 years (2019-2023). The main focus is situated on the metrics used for greenness evaluation of the methods applied for the determination of bioactive agents. It critically evaluates and compares the demands of the real applicability of the methods in quality control and clinical environment with the requirements of the green analytical chemistry (GAC). Greenness and practicality of the summarized methods are re-evaluated or newly evaluated with the use of the dominant metrics tools, i.e., Analytical GREEnness (AGREE), Green Analytical Procedure Index (GAPI), Blue Applicability Grade Index (BAGI), and Sample Preparation Metric of Sustainability (SPMS). Moreover, general conclusions and future perspectives of the greening procedures and greenness evaluation metrics systems are presented. This paper should provide comprehensive information to analytical chemists, biochemists, and it can also represent a valuable source of information for clinicians, biomedical or quality control laboratories interested in development of analytical methods based on greenness, practicality, and sustainability.

Nanocomposite microbeads (average diameter = 10-100 µm) were prepared by a microemulsion-solidification method and applied to the magnetic solid-phase extraction (m-SPE) of fourteen analytes, among pesticides, drugs, and hormones, from human urine samples. The microbeads, perfectly spherical in shape to maximize the surface contact with the analytes, were composed of magnetic nanoparticles dispersed in a polylactic acid (PLA) solid bulk, decorated with multi-walled carbon nanotubes (mPLA@MWCNTs). In particular, PLA was recovered from filters of smoked electronic cigarettes after an adequate cleaning protocol. A complete morphological characterization of the microbeads was performed via Fourier-transform infrared (FTIR) spectroscopy, UV-Vis spectroscopy, thermogravimetric and differential scanning calorimetry analysis (TGA and DSC), scanning electron microscopy (SEM) and X-ray diffraction analysis (XRD). The recovery study of the m-SPE procedure showed yields ≥ 64%, with the exception of 4-chloro-2-methylphenol (57%) at the lowest spike level (3 µg L-1). The method was validated according to the main FDA guidelines for the validation of bioanalytical methods. Using liquid chromatography-tandem mass spectrometry, precision and accuracy were below 11% and 15%, respectively, and detection limits of 0.1-1.8 µg L-1. Linearity was studied in the range of interest 1-15 µg L-1 with determination coefficients greater than 0.99. In light of the obtained results, the nanocomposite microbeads have proved to be a valid and sustainable alternative to traditional sorbents, offering good analytical standards and being synthetized from recycled plastic material. One of the main objectives of the current work is to provide an innovative and optimized procedure for the recycling of a plastic waste, to obtain a regular and reliable microstructure, whose application is here presented in the field of analytical chemistry. The simplicity and greenness of the method endows the procedure with a versatile applicability in different research and industrial fields.

Green bioanalytical techniques aim to reduce or eliminate the hazardous waste produced by bioanalytical technologies. A well-organized and practical approach towards bioanalytical method development has an enormous contribution to the green analysis. The selection of the appropriate sample extraction process, organic mobile phase components and separation technique makes the bioanalytical method green. UHPLC-MS is the best option, whereas supercritical fluid chromatography is one of the most effective green bioanalytical procedures. Nevertheless, there remains excellent scope for further research on green bioanalytical methods. This review details the various sample preparation techniques that follow green analytical chemistry principles. Furthermore, it presents green solvents as a replacement for conventional organic solvents and highlights the strategies to convert modern analytical techniques to green methods.