Simultaneous Determination Research Articles

A novel synchronous fluorescence approach for the simultaneous determination of tafamidis and carvedilol in human plasma at nanogram levels: Compliance with greenness metrics

In this study, a green and highly sensitive synchronous spectrofluorimetric method was developed and validated for the simultaneous estimation of tafamidis (TAF) and carvedilol (CAR) for the first time. The method utilized the inherent fluorescence properties of both drugs, offering high sensitivity and selectivity. The two drugs were measured concurrently at 292 nm and 242 nm for TAF and CAR, respectively at △λ = 100 nm using water as a green diluting solvent. The method was then validated following the International Council for Harmonization (ICH) recommendations, demonstrating acceptable linearity, precision, accuracy, and selectivity within the specified concentration ranges. The concentrations were linear over the ranges of 10.0–600.0 and 1.0–50.0 ng/mL with limits of detection of 2.67 and 0.08 ng/mL for TAF and CAR, respectively. Due to the high sensitivity, the developed method was applied for analysis of the studied drugs in human plasma samples with high %recoveries (98.27–101.82), indicating good bioanalytical applicability. The greenness and eco-friendliness of the designed methodology were verified using the Green Analytical Procedure Index (GAPI) and the Analytical GREEnness (AGREE) tools. The designed approach is the first analytical approach for TAF and CAR simultaneous analysis without the need for any hazardous chemicals or reagents. The high sensitivity, simplicity, rapidity, greenness, and cost-effectiveness of the proposed method make it suitable for the therapeutic drug monitoring of the investigated drugs.

A pioneering electrochemical sensor for the simultaneous determination of nitrofurantoin and furazolidone residues in food and municipal wastewater samples

In this study, a pioneering electrochemical sensor was developed for simultaneously determining nitrofurantoin (NFT) and furazolidone (FZD) residues in food and municipal wastewater samples. The sensor was prepared by integrating gold‑silver-alloy nanocoral clusters (Au-Ag-ANCCs) with zinc oxide nanoparticles (ZnO-NPs), carbon paste electrode (CPE) and polyethylene oxide (PEO) nanocomposites. The surface morphology and elemental compositions of Au-Ag-ANCCs/ZnO-NPs-CPE/PEO were characterized by FT-IR, XRD, SEM, EDX, EIS, and CV. The sensor showed exceptional performance over a wide linear range, from 1.0 pM to 250 μM for NFT and 0.9 nM to 360 μM for FZD. The detection and quantification limits were found to be 0.26 pM and 0.88 pM for NFT and 0.023 pM and 0.076 pM for FZD, respectively. In addition, the sensor exhibited excellent repeatability, reproducibility, selectivity, and long-lasting stability. When applied to the detection of AZM and ENF residues in poultry, fish, honey, dairy products and municipal wastewater, it exhibited excellent recoveries of 96.3–102.8% and relative standard deviations between 1.87% and 1.53%. In general, the developed sensor represents a significant advance in the fight against antibiotic residue pollution.

Determination of doxorubicin in plasma and tissues of mice by UPLC-MS/MS and its application to pharmacokinetic study

A rapid and sensitive ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was established for the simultaneous determination of doxorubicin (DOX) in mouse plasma and tissues, including the heart, liver, spleen, lung, kidney and tumor, and to investigate the pharmacokinetics and distribution in mice. In this study, daunorubicin (DNR) was used as an internal standard, and the mobile phase consisted of ammonium formate 2 mM containing 0.1 % formic acid (A) and acetonitrile (B), the chromatographic column was ACQUITY UPLC BEHTM C18 with a gradient elution at a flow rate of 0.2 mL/min. Electrospray ionization (ESI) in positive ion pattern was utilized for the ion separation of DOX, with the ions used for quantitative analysis being DOX m/z 544.28 → 397.10 and DNR m/z 528.35 → 321.08, respectively. The results showed that a good linear relationship in the calibration curve range of 1–800 ng/mL in mouse plasma and 1–2500 ng/g in tissues (R2 > 0.99) with the limits of quantification of 1 ng/mL in plasma and tissues. The method exhibited good matrix effect and extraction recovery, with the intra-day and inter-day precision of plasma and tissue were less than 10.3 % and 15.4 %, and the relative error (RE) were both less than ±14.8 % and ±18.9 %, respectively. The stability results under different conditions were found to be accurate. It also revealed the distribution of DOX in various tissues of mice, with the concentration ranking as liver > heart > kidney > spleen > lung > tumor. This method was successfully used to the study for the pharmacokinetics in plasma and drug distribution in tissues of BALB/c mice.

Comprehensive assessment of clean-up strategies for optimizing an analytical multi-method to determine pesticides and mycotoxins in Brazilian medicinal herbs using QuEChERS-LC-TQ-MS/MS.

The use of medicinal herbs has increased significantly. However, the presence of pesticide residues and mycotoxins in medicinal herbs has generated constant discussion and concern among regulatory agencies. Developing and validating an analytical method for determining pesticides and mycotoxins in medicinal plants is challenging due to the naturally occurring substances in these plants. The purpose of this work was to develop and to optimize a sensitive, accurate, precise, effective QuEChERS method for simultaneous determination of over 160 pesticide and mycotoxin residues in complex medicinal plant matrices using LC-TQ-MS/MS. A comprehensive comparison of clean-up procedures and other parameters was conducted to achieve this goal. The validation procedure was performed according to SANTE 11312/2021. More polar analytes, such as acephate, methamidophos and omethoate, presented a higher negative matrix effect in both Melissa officinalis L. and Malva sylvestris L. However, other molecules, such as spirodiclofen, showed a 24% signal enhancement in M. officinalis and a 46% signal suppression in M. sylvestris, indicating that a representative matrix-matched calibration would lead to inaccurate quantification of the analyte. Accuracy and precision were satisfactory according to SANTE 11312/2021 for 157 pesticide residues and mycotoxins in M. officinalis and for 152 molecules in M. sylvestris. LOQs at 10 µg kg-1 were achieved for 117 pesticides in M. officinalis and 99 pesticides in M. sylvestris. Among the mycotoxins, all four aflatoxins (B1, B2, G1 and G2) presented LOQs of 5 µg kg-1, and ochratoxin A had an LOQ of 10 µg kg-1 in M. officinalis. The same LOQ values were shown for these mycotoxins in M. sylvestris, except for aflatoxin B2 and ochratoxin A, which had LOQs of 20 µg kg-1. Moreover, in Southern Brazil, there has been no previous study on mycotoxin and pesticide contamination in medicinal herbs. Therefore, the application of this method was assessed through the analysis of forty-two real samples. Imidacloprid was found in M. officinalis, and methyl pirimiphos was found in M. sylvestris. The proposed method not only serves as a helpful tool for routine monitoring but also offers a basis for further research on risk assessment and control in food safety.

Simultaneous determination of total homocysteine, methionine, methylmalonic acid and 2-methylcitric acid in dried blood spots by ultra-performance liquid chromatography–tandem mass spectrometry

Homocysteine, methionine, methylmalonic acid and 2-methylcitric acid are clinically relevant markers in the methionine, propionate, and cobalamin metabolism. This study aimed to develop and validate an ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for simultaneously determining total homocysteine, methionine, methylmalonic acid and 2-methylcitric acid in dried blood spots. Three 3.2 mm discs were punched from each calibrator, quality control, and sample dried blood spot into a 96-well U-plate. Each sample was spiked with internal standards and extracted. Then the supernatant was transferred to another 96-well U-plate. After nitrogen drying, the dried residues were reconstituted, centrifuged, and the resulting supernatant was transferred to another 96-well plate for analysis. The method was performed using UPLC-MS/MS within 3 min, validated according to guidance documents, and applied to 72 samples from confirmed patients with methionine, propionate, and cobalamin metabolism disorders. The UPLC-MS/MS method provided satisfactory separation of the four analytes. The R2 values were ≥ 0.9937 for all analytes. The recoveries ranged from 94.17 to 114.29 %, and the coefficients of variation for intraday and interday precision were 0.19 % to 5.23 % and 1.02 % to 6.89 %, respectively. No significant carry-over was detected for the four analytes, and most of confirmed samples exhibited biomarker patterns characteristic of the relevant disorders. A simple and fast UPLC-MS/MS method was successfully developed, validated, and applied to clinical samples for the simultaneous determination of total homocysteine, methionine, methylmalonic acid, and 2-methylcitric acid in dried blood spots.

SIMULTANEOUS DETERMINATION OF ASCORBIC ACID, URIC ACID, AND DOPAMINE ON CARBON NANOTUBE PASTE ELECTRODE

Background: Ascorbic acid (AA), uric acid (UA), and dopamine (DA) play crucial roles in human metabolism. These substances coexist in biological fluids, and their levels are directly associated with various pathologies. A significant problem encountered in the direct and simultaneous electrochemical detection of AA, UA, and DA is that these species present very close oxidation potentials on most electrode materials, leading to an overlap in the voltammetric response. Aim: The main goal of this work was to determine the concentration of AA, UA, and DA in a natural water sample on a carbon nanotube paste electrode (CNTPE). Methods: All voltammetric measurements were performed on a µAutolab potentiostat/galvanostat (Metrohm) connected to an electrochemical cell of three electrodes: working, reference (Ag/AgCl, KCl3.0M), and auxiliary (platinum). The working electrode was handmade in our laboratory. The following proportions were used to prepare the paste: 50% CNT + 50% mineral oil and 65% CNT + 35% mineral oil. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were used for the electroanalytical study. Results: The linear ranges for the simultaneous determination of AA, DA, and UA by DPV were: 0.45 – 1.0 mM, 50 – 200 ?M, and 10 – 90 ?M, respectively. The LODs of the proposed method for AA, DA, and UA were: 7.97 mM; 8.57 ?M, and 5.96 ?M, respectively. The relative standard deviations (RSD) were 4.6, 2.8, and 1.6% for 0.45 mM of AA, 50 ?M of DA, and 50 ?M of UA. Discussion: The oxidation mechanism of: AA, UA, and DA is a process that involves two electrons and 2 protons. Electrochemical detection of DA in the presence of high levels of AA on carbon-based electrodes becomes difficult due to the catalytic oxidation of AA by DA. For the three molecules, AA, UA, and DA, it is observed that the oxidation peak currents increased with increasing concentration. Conclusions: CNTPE allowed the separation of the oxidation peaks of the ternary mixture of AA, UA, and DA by cyclic voltammetry and, when associated with DPV allowed the simultaneous quantitative determination of AA, UA, and DA.

Comprehensive Study of Total Nitrogen Content and Microfluidic Profiles in Additive-Enriched Plant-Based Drinks

The growing consumption of plant-based milk substitutes raises important questions about their composition. The various additives used by manufacturers, including those employed as flavor enhancers, protein additives, and stabilizers, may contain both protein and non-protein nitrogen components. In our study, we examined not only popular milk alternatives but also other milk substitutes made from specific plants. We present a reproducible and rapid method for the simultaneous qualitative and quantitative determination of the total nitrogen content in milk alternatives, focusing on applicability. Using the microchip gel electrophoretic method, we determined that the total nitrogen content differed from the protein content indicated on the packaging. Our results, along with statistical evaluations, supported the hypothesis that different brands of products, derived from the same plant source, resulted in different microfluidic profiles, likely due to the presence of additives. As expected, the microfluidic profiles of additive-free products differed from those of fortified products made from the same plant-based milk replacer. Total nitrogen content provides crucial information for individuals with kidney disease, as is essential to reduce the burden on the kidneys to slow deterioration, alleviate symptoms and avoid complications.

2D/3D hierarchical porous structure of mNPC/SMOH@C to construct an electrochemical sensor for the simultaneous determination of p-acetylaminophenol and p-aminophenol

BackgroundAs persistent organic pollutants (POPs), the accumulation of p-acetylaminophenol (PAT) and p-aminophenol (PAP) in water can seriously damage the health of plants and animals, ultimately leading to threats to human health and safety. Electrochemical sensors have the advantages of being fast, inexpensive, and accurate compared to the complex, expensive, and cumbersome conventional analytical methods. In this study, we designed and synthesized composites with two-dimensional/three-dimensional (2D/3D) porous structures to construct an efficient electrochemical platform for the simultaneous detection of PAT and PAP. ResultsIn this work, a novel 3D foamy birnessite Na0.55Mn2O4·1.5H2O@C (SMOH@C) was synthesized, which was composited with 2D ordered mesoporous nanosheets (mNPC) to construct electrochemical sensors detecting PAT and PAP simultaneously. The prepared 2D/3D porous structure of mNPC/SMOH@C increased the exposure of active sites due to its large specific surface area. The introduction of a 3D carbon skeleton altered the charge transfer rate of SMOH@C, and the rich pore structure and oxygen-rich vacancies created favorable conditions for the diffusion and adsorption of PAP and PAT, which enabled the sensitive detection of PAT and PAP. The constructed mNPC/SMOH@C electrochemical sensor could simultaneously detect PAT (1 × 10−7 - 1 × 10−4 M) and PAP (5 × 10−8 - 1 × 10−4 M) with detection limits of 20.4 nM and 30.1 nM, respectively. The sensor has good repeatability (RSD <4 %) and reproducibility (RSD <4 %), and satisfactory recoveries (96.7–102.8 %) were obtained in the analysis of natural water samples. SignificanceIn this paper, for the first time, we present the synthesis of 3D foam birnessite and its composite with mNPC for the electrochemical simultaneous detection of PAT and PAP. Our proposed strategy for fabricating 2D/3D porous composites lays the foundation for the design and synthesis of other porous materials. In addition, this study provides new ideas for developing efficient and practical electrochemical sensors for detecting pollutants in aquatic environments.

Miniaturized green capillary electrophoresis system for the simultaneous analysis of Linagliptin and cefiximein in plasma

A novel combination therapy, consisting of the antidiabetic drug linagliptin (LIN) and the third-generation cephalosporin antibiotic cefixime (CEF), has recently been introduced to combat infections in diabetic patients. However, there is no published method for their in-vivo simultaneous determination in clinical biological specimens to support their pharmacokinetics and therapeutic monitoring. This study focuses on the development of a miniaturized capillary electrophoresis system-assisted with photodiode array detection (CE-PDA) for the simultaneous determination of LIN and CEF in clinical settings for analysis of plasma samples containing LIN and CEF. The conditions of electrophoretic separation of LIN, CEF, and Ibuprofen (as an internal standard), and the analysis procedures were successfully established. The linear range of the CE-PDA method was determined to be 0.5–100 µg mL−1 for LIN and 1–100 µg mL−1 for CEF. The CE-PDA approach exhibited high sensitivity, with limits of quantitation of 0.9 µg mL−1 for LIN and 1.2 µg mL−1 for CEF. In addition, the CE-PDA system was validated, and subsequently applied to real plasma samples withdrawn from rats received concurrent administration of LIN and CEF. The plasma protein was precipitated by acetonitrile. The miniaturized features of the system and its environmental impact were confirmed using three different metric tools. Additionally, the proposed CE-PDA system proved to be time-saving and cost-effective, making it highly suitable for therapeutic drug monitoring of LIN and CEF in clinical settings.

Validation and measurement uncertainty of analytical methods for various azo dye adulterants in Curcuma longa L.

Food adulteration involving the illegal addition of dyes to foodstuffs has become an alarming issue in recent years. This study developed and validated a high-performance liquid chromatography (HPLC)-DAD (diode array detector) method for the simultaneous determination of nine azo dyes (Butter Yellow, Sudan Orange G, Para Red, Sudan I, Sudan II, Sudan III, Sudan IV, Sudan Red 7B, and Scarlet 808). Moreover, a qualitative analysis method using liquid chromatography-tandem mass spectrometry was developed to more accurately identify peaks detected in HPLC-DAD. The calibration curve represented good linearity (r2≥0.9998) over the measured concentration range of 0.5-25mg/kg. limit of detection and limit of quantification were 0.01-0.04 and 0.04-0.12mg/kg, respectively. Accuracy and precision were 96.0-102.6 and 0.16-2.01 (relative standard deviation%), respectively. Additionally, the measurement uncertainty and HorRat value were estimated. Several Curcuma longa L. distributed in Korea were collected and monitored for azo dye contaminants. PRACTICAL APPLICATION: The proposed HPLC-DAD method represents a significant advancement in the field, offering a reliable means of quantifying azo dyes and identifying their presence even at trace levels in adulterated turmeric. This not only contributes to ensuring the safety and integrity of turmeric products but also establishes precedent for robust analytical techniques in addressing food safety challenges.

A Reverse Thinking Based on Partially Methylated Aldononitrile Acetates to Analyze Glycoside Linkages of Polysaccharides Using Liquid Chromatography-Multiple Reaction Monitoring Mass Spectrometry.

Glycoside linkage analyses of medicine and food homologous plant polysaccharides have always been a key point and a difficulty of structural characterization. The gas chromatography-mass spectrometry (GC-MS) method is one of the commonly used traditional techniques to determine glycoside linkages via partially methylated alditol acetates and aldononitrile acetates (PMAAs and PMANs). Due to the simplicity of derivatization and the highly structural asymmetry of PMANs, reverse thinking is proposed using liquid chromatography-electrospray ionization-multiple reaction monitoring mass spectrometry (LC-ESI-MRM-MS) for the first time to directly determine the neutral and acidic glycosyl linkages of polysaccharides. The complete characterization of glycoside linkages deduced from PMANs was achieved using a combination of tR values, characteristic MRM ion pairs, diagnostic ESI+-MS/MS fragmentation ions (DFIs), and optimal collision energy (OCE). The DFI and OCE parameters were confirmed to be effective for the auxiliary discrimination of some isomers of the PMANs. The practicality of LC-ESI+-MRM-MS was further verified by analyzing the glycoside linkages of polysaccharides in five medicine and food homologous plants. This method can serve as an alternative to GC-MS for the simultaneous determination of neutral and acidic glycosyl linkages in polysaccharides.

Determination of persistent organic pollutants in urban and peri-urban wastewater sludge: environmental and carcinogenic human risk assessment in the case of land application.

The management of digested sludge derived from treatment water plants is a problem worldwide due to the possible transfer of contamination from sludge to amended soil and, in turn, to humans. Within this work, through a chemometric experimental design, a robust GC-MS method for the simultaneous determination of two classes of micropollutants of concern (polycyclic aromatic hydrocarbons-PAHs-and polychlorinated biphenyls-PCBs-including dioxin-like compounds) was developed using microwave-assisted extraction (MAE). The method, which showed interesting greenness features in compliance with the 12 principles of Green Chemistry, allowed PCB and PAH extraction with recoveries higher than 75% (RSD < 14%) with method detection limits between 4.6 and 11.5µgkg-1 (PAHs) and between 6.9 and 13.7µgkg-1 (PCBs), without preconcentration. The matrix effect was below 20%. The validated protocol allowed the characterization of two digested sludges sampled in an urban and a peri-urban district, representative models of two scenarios of different anthropic impacts. This study highlighted higher contamination for the sludge derived from the urban area, accounted for by the 4-ring PAHs. In addition, since carcinogenic PAHs were detected, the environmental risk (by mean of the comparison of predicted vs predicted no-effect concentrations) and the carcinogenic human risk from dermal contact (through the calculation of the adsorbed lifetime average daily dose) were assessed in the case of soils amended with the sludges considered, pointing out that the measured concentrations do not pose a risk.

Simultaneous Determination of Ni(II) and Co(II) in Aqueous Solution Using an Image-Based Do-It-Yourself Photometer

Simultaneous Determination of Ni(II) and Co(II) in Aqueous Solution Using an Image-Based Do-It-Yourself Photometer

Greenness and practicability assessment of a new HPLC-DAD method for simultaneous determination of three drugs used for a triple-therapy regimen for helicobacter pylori and application to a pharmacokinetic study

Improving the environmental friendliness of laboratory procedures has become very strongly recommended. In this research, several metric tools evaluating the analytical methods, including eco-scale, analytical greenness calculator (AGREE), green analytical procedure index (GAPI), red–green–blue software (RGB) and blue applicability grade index (BAGI) have been used to assess the greenness, performance and practicality of a new useful HPLC-DAD method. The main cause of peptic ulcers and the problems that follow is Helicobacter pylori. Due to the bacteria’s high resistance, different medications are co-administered to overcome the resistance and manage the symptoms. Two antibiotics are mostly used to decrease bacterial resistance in addition to proton pump inhibitors. Pantoprazole, Levofloxacin, and Amoxicillin are co-administered in a triple therapy regimen for suppressing Helicobacter pylori. In this work, the first-time simultaneous estimation of the three medications in rat plasma has been designed and utilized to investigate pharmacokinetics using a new HPLC method with outstanding greenness and practicability. The method involved using a C18 analytical column with an eluent of acetonitrile: 0.03 M Na2HPO4 buffer (20:80, v/v) of 1.5 mL min−1 flow rate. Oxytetracycline was used as an internal standard and the drugs were determined at 230 nm. The validation protocol was adopted according to FDA instructions, and the results proved the ability of the new method to estimate the three medications in rat plasma.

UHPLC-PDA-ELSD-MS-based simultaneous determination of diterpenoid alkaloids in commercially important Himalayan medicinal plant Aconitum heterophyllum Wall. and network pharmacology-based target prediction

Aconitum heterophyllum Wall., a commercially important Himalayan medicinal plant, is used in various herbal formulations and has high market demand. Given its esteemed medicinal properties, considerable demand, and prioritized status, there’s a pressing requirement for thorough quality assessment methods to ensure high throughput. Genus Aconitum is also well known for its toxicity owing to the presence of diester diterpenoid alkaloids. Hence it is essential to develop a UHPLC-PDA-ELSD-MS based quantification method enabling simultaneous quantification of primary marker compounds alongside toxic diterpenoid alkaloids. The method showcased strong linearity, with detection and quantification limits covering a broad range. Precision was evident with consistently low relative standard deviations both within and across days. Furthermore, accuracy was demonstrated within acceptable bounds. Quantification results revealed the maximum content of atisinium and hetisine in hydroethanolic root extract [atisinium (≅78.88 mg/g) and hetisine (≅50.17 mg/g)] In addition, a network pharmacology-based approach has been applied to predict potential biological targets. The network pharmacology approach suggests the plant’s potential in treating neuralgia, renal fibrosis, diabetes mellitus, lung diseases, cancer, and more, emphasizing the need for scientific validation and indicating future research directions. Overall, the developed method represents a reliable and efficient quality assessment method for the simultaneous quantification of marker compounds and toxic diterpenoid alkaloids in the roots of A. heterophyllum. Network pharmacology predicts pharmacological potentials that require scientific validation highlighting future scope.

Optimization of Sample Preparation Procedure for Determination of Fat-Soluble Vitamins in Milk and Infant Food by HPLC Technique

Background: The analysis of vitamins in baby food is a challenging task given the complexity of the food matrix, vitamin stability, and strict regulations of the European Union regarding permissible deviations from declared values. Vitamins in food exist in different concentrations and forms and have different stabilities; thus, the preparation of samples for a reliable analysis using the same procedure is not straightforward. Therefore, significant attention has been devoted to optimizing sample preparation in the analysis of vitamins. Methods: This study aims to determine which of the sample preparation and extraction methods is the most efficient for the simultaneous determination of vitamins A, D, E, and K in milk and baby food using high-performance liquid chromatography (HPLC). Different samples of baby food were prepared in seven different ways based on four methods (saponification, enzymatic hydrolysis, solvent extraction, and solid-phase extraction). Results and Conclusion: According to the validation parameters, the optimal preparation method proved to be solid-phase extraction with a C18 stationary phase, with recoveries of 97.4%, 96.1%, 98.3%, and 96.2% for vitamins A, D, E, and K, respectively, and HPLC with a UV–Vis detector was identified as a sufficiently sensitive technique for the identification and quantification of fat-soluble vitamins in milk and baby food.

Screening and Simultaneous Determination of 80 Veterinary Drug Residues in Food by HPLC-MS/MS

Screening and Simultaneous Determination of 80 Veterinary Drug Residues in Food by HPLC-MS/MS

Novel RP-HPLC–DAD approach for simultaneous determination of chlorphenoxamine hydrochloride and caffeine with their related substances

Ensuring the quality control of active pharmaceutical ingredients is crucial for drug products being introduced into the market. Even for established drugs, it is necessary to maintain a cutting-edge impurity control system. To analyze caffeine and chlorphenoxamine hydrochloride in their binary mixture, as well as theophylline and chlorphenoxamine N-oxide as related substances, a reversed phase-high performance liquid chromatography combined with a diode array detector system was created. The chromatographic separation was conducted using a C18 X-select Waters® column. The mobile phase consisted of 20.0 mM potassium dihydrogen phosphate modified to pH 3 with o-phosphoric acid and methanol. A gradient elution program was adopted at a flow rate of 1.3 mL/min and detected at a wavelength of 222 nm. The present methodology demonstrates a concentration ranging from 2–60, 1–80, 0.5–20 to 0.4–20 µg/mL for chlorphenoxamine hydrochloride, caffeine, chlorphenoxamine N-Oxide and theophylline, respectively. Chlorphenoxamine N-Oxide, being an impurity of chlorphenoxamine was prepared by refluxing intact drug with 5% H2O2 for 24 h at 100 °C. One of the objectives of the analytical community is to promote the adoption of green analysis methods, which involve the development of environmentally friendly techniques. The levels of greenness and whiteness were evaluated using four specific tools: Eco-Scale System, GAPI, AGREE, and RGB tool. Furthermore, we have evaluated the greenness of the analytical method presented and compared its performance and greenness to that of the approach described in the literature. In this study, results from CPX and CAF analysis were compared to those obtained in a previous study. The result shows that there is no notable variation in precision and accuracy. The proposed method was validated in accordance with the requirements of ICH.

Development of LC–MS/MS Method for the Simultaneous Detection of Emerging Contaminants in Aquatic Matrices

Emerging contaminants (ECs) are substances that have no defined environmental quality standards or regulations, and have the potential to pose major adverse impacts on the environment and human health. The detection of contaminants in the natural environment is the key step for establishing precise environmental risk assessment approach for ECs. However, ECs come from different origins with various physicochemical properties, making their detection a complicated process. Moreover, their presence in the aquatic environment at trace concentration range (ng/L-µg/L), requires an accurate detection at low concentration levels. This study aims to develop an efficient analytical method for simultaneous determination of 5 different ECs in aqueous solution based on solid phase extraction technique (SPE) followed by liquid chromatography-mass spectrometry (LC–MS/MS). High recovery rates (72% to 114%) were achieved for all targeted compounds. Ciprofloxacin (CIP), diuron (DIU), terbutryn (TER) and diclofenac (DIC) had a limit of detection (LOD) of 5 µg/L and a limit of quantification (LOQ) of 10 ng/L, while LOD and LOQ for EE2 were 25 µg/L and 50 ng/L, respectively. These results confirm that the optimized method can be applied for extraction and analysis of ECs from different classes in the aquatic environment.

A new chemometrically optimised HPLC method for the simultaneous determination of imatinib mesylate and capecitabine, the active medicinal components

ABSTRACT Anticancer drugs such as imatinib mesylate (IMP) and capecitabine (CAP) and their metabolites enter the water cycle through wastewater treatment plant effluents or directly into the water cycle due to their limited biodegradability in typical wastewater treatment plants. However, their long-term effects on water resources are unknown due to their toxicity. The hazards concerned with chronic exposure to these substances raise concerns about their impact on organisms, environmental safety and biodiversity conservation. Therefore, in this study, a chemometrically optimised HPLC method was developed for the simultaneous determination of trace amounts of cytotoxic agents IMP and CAP used in cancer treatment in environmental water, synthetic urine samples and drug samples. Using the Box-Behnken design, optimum conditions discovered using the traditional method were optimised. The effect of each element was evaluated in the design by four factors based on HPLC determination. For the examined levels, mobile phase 1, mobile phase 2 ratio, flow rate, and column temperature parameters for the HPLC method were determined. Using regression analysis on the experimental results, the factors influencing resolution were identified. To achieve the reliability of the results, the Analysis of Variance (ANOVA) test was used. The ANOVA test was employed to verify the consistency of the data. With the information gathered, a model was developed. HPLC was used to examine the target chemicals. A good linearity (R2 > 0.99) was established for the IMP and CAP in the concentration ranges of 1.18–23.59 µg mL−1 and 0.76–15.09 µg mL−1, respectively, under optimum circumstances. The recoveries for spiked samples at three concentration levels ranged from 98.31 to 101.11. The created method has been applied to synthetic urine samples, regional environmental water samples, and pharmaceutical samples with success.