Use of Micellar Liquid Chromatography to Determine Mebendazole in Dairy Products and Breeding Waste from Bovine Animals

Mebendazole is an anthelmintic drug used in cattle production. However, residues may occur in produced food and in excretions, jeopardizing population health. A method based on micellar liquid chromatography (MLC) was developed to determine mebendazole in dairy products (milk, cheese, butter, and curd) and nitrogenous waste (urine and dung) from bovine animals. Sample treatment was expedited to simple dilution or solid-to-liquid extraction, followed by filtration and direct injection of the obtained solution. The analyte was resolved from matrix compounds in less than 8 min, using a C18 column and a mobile phase made up of 0.15 M sodium dodecyl sulfate (SDS)–6% 1-pentanol phosphate buffered at pH 7, and running at 1 mL/min under isocratic mode. Detection was performed by absorbance at 292 nm. The procedure was validated according to the guidelines of the EU Commission Decision 2002/657/EC in terms of: specificity, method calibration range (from the limit of quantification to 25–50 ppm), sensitivity (limit of detection 0.1–0.2 ppm; limit of quantification, 0.3–0.6 ppm), trueness (92.5–102.3%), precision (<7.5%, expressed at RSD), robustness, and stability. The method is reliable, sensitive, easy-to-handle, eco-friendly, safe, inexpensive, and provides a high sample-throughput. Therefore, it is useful for routine analysis as a screening or quantification method in a laboratory for drug-residue control

Simultaneous detection of hazardous skin whitening agents in Indian cosmetic products using a green chromatographic technique

The present work mainly highlights the simultaneous detection of four skin whitening agents i.e. hydroquinone (HQ), resorcinol (RS), catechol (CC) and 3,3′-dichlorobenzidine (DCB) in facial creams and body lotion. Among these, the first three are positional isomers of dihydroxybenzene so simultaneous separation is difficult with the conventional reverse-phase high-performance liquid chromatographic technique (RP-HPLC). The selected skin whitening agents were detected in facial cream and body lotion using micellar liquid chromatography coupled to a photodiode array detector (MLC-PDA). In the present study, optimization of the method was accomplished using response surface methodology (RSM) with central composite design (CCD). The second-order polynomial model for predicting the optimal chromatographic run time was evaluated by the analysis of variance (ANOVA) and 3D response surface plots for the interactions between three variables were constructed. Three experimental parameters which were chosen as independent variables were; surfactant concentration (SDS), the volume percentage of organic modifier (OM) and pH of the mobile phase. The second-order polynomial model for predicting the optimal chromatographic run time was evaluated by the analysis of variance (ANOVA) and 3D response surface plots for the interactions between three variables were constructed. Three experimental parameters which were chosen as independent variables were; surfactant concentration (SDS), percentage of organic modifier (OM) and pH of the mobile phase. The second-order polynomial model for predicting the optimal chromatographic run time was evaluated by the analysis of variance (ANOVA) and 3D response surface plots for the interactions between three variables were constructed. Three experimental parameters which were chosen as independent variables were; surfactant concentration (SDS), percentage of organic modifier (OM) and pH of the mobile phase. The optimized mobile phase was 0.15 M SDS and 7% 1-butanol, buffered at pH 7 with 0.01 M NaH2PO4. The chromatographic run time for simultaneous determination of selected analytes was 7.5 min. The correlation coefficient (r2) values were satisfactory between 0.998–0.999 over the linear concentration range. Limits of detection (LODs) and the limits of quantification (LOQs) for the four skin whitening agents were in the range of 0.05–0.07 μg/mg and 0.11–0.14 μg/mg, respectively. Trueness (98.4–102.7%) and precision (< 4.3%) were acceptable. The developed method was fast, cost-effective, and green which could easily analyze complex matrices (facial creams, body lotion) without any pretreatment other than filtration. The results indicated that the MLC-PDA method proved to be more suitable for the simultaneous separation of selected positional isomers

A method to determine two antibiotics prescribed to treat nosocomial infections in plasma and urine by micellar liquid chromatography

Combined prescription of the antimicrobial drugs linezolid and meropenem is a common strategy to treat multidrug-resistant nosocomial infections. We propose an innovative method to determine these two drugs in plasma and urine, based on micellar liquid chromatography. Both biological fluids were diluted in mobile phase, filtered and directly injected, without any extraction step. Using a C18 column and a mobile phase of 0.1 M sodium dodecyl sulfate – 10 % methanol, phosphate buffered at pH 3, running under isocratic mode, both antibiotics were eluted without overlapping in<15 min. Detection was by absorbance: 255 nm for linezolid and 310 nm for meropenem. The influence of sodium dodecyl sulfate and methanol concentration on retention factor was established for both drugs using an interpretative approach assisted by chemometrics. The procedure was successfully validated following the guidelines of 2018 Bioanalytical Method Validation Guidance for Industry in terms of: linearity (determination coefficients over 0.99990), calibration range (1 – 50 mg/L), instrumental and method sensitivity, trueness (bias of −10.8 to + 2.4%), precision (relative standard deviation of < 10.2%), dilution integrity, carry-over effect, robustness and stability. It should be emphasized that the method uses low volumes of toxic and volatile solvents and can be achieved in a short period. The procedure was found useful for routine analysis, as it was cost-affordable, more eco-friendly and safer than hydroorganic HPLC, easy-to-handle and highly sample-throughput. Finally, it was applied to incurred samples of patients taking this medication

Detection of most commonly used pesticides in green leafy vegetables from sagar, india using direct injection hybrid micellar liquid chromatography

Imidacloprid, chlorpyrifos, profenofos and cypermethrin are most commonly applied pesticides on green leafy vegetables. After a survey conducted to know the pesticide management practices in Sagar, India, a procedure based on hybrid micellar liquid chromatography coupled to a photodiode array detector has been developed and validated to monitor imidacloprid, chlorpyrifos, profenofos and cypermethrin content in green leafy vegetables. The method was validated following the guideline of SANTE/11,312/2021 in terms of: selectivity, linearity (r2> 0.998), limit of quantification (0.09–0.25 mg/Kg, depending on the analyte under investigation), precision (<8.1%), and robustness (<5%). Chlorpyrifos was found to be the most commonly used pesticide among vegetable growers. It was found in seventy-six percent samples, profenofos in fifty-one percent, imidacloprid in eight percent and cypermethrin in four percent of the analyzed green leafy vegetable sample either individually or in combination. Sixteen percent of the collected samples were found to be negative for the selected pesticides. The developed procedure is rapid, easy to handle, green since it uses a low amount of toxic chemicals providing reliable results. The method was used to evaluate the eventual correlation between the analytical data and the information collected from the producers and users of these pesticides.The authors are thankful to DST-FIST and DST-PURSE (Department of Science and Technology; Government of India) for supporting with FIST and PURSE scheme (Sl.No.64 Dated 31–05–2016). Work supported by Grant PID2019-106708GB-I00 funded by MCIN (Ministry of Science and Innovation of Spain)/AEI/10.13039/501100011033. Hemlata Bhamdare [UGC-Ref.No.3354/(OBC)(NET-DEC.2015)] and Priyanka Pahade [UGC-Ref.No.3335/(Sc) (NET-DEC.2015)] are grateful to University Grant Commission (UGC) for providing a Senior Research Fellowship

Micellar liquid chromatography as a sustainable tool to quantify three statins in oral solid dosage forms

A method based on micellar liquid chromatography has been developed to determine rosuvastatin, lovastatin and simvastatin in oral solid dosage forms. Samples were solved in mobile phase up to the target concentration, filtered and directly injected. The three statins were resolved in 30 min, using an aqueous solution of 0.10 M sodium dodecyl sulfate – 7.0% 1-butanol, buffered at pH 3 with 0.01 M phosphate salt as mobile phase, running under isocratic mode at 1 mL/min through a C18 column. Detection was at 240 nm. The effect of sodium dodecyl sulfate on elution strength was more important than that of the organic solvent. The procedure was successfully validated by the guidelines of the International Council for Harmonization in terms of: specificity, linearity (r2 > 0.990), calibration range (1.5 - 15 mg/L for rosuvastatin, 0.5–10 mg/L for lovastatin and simvastatin), limit of detection (0.4, 0.2 and 0.15 mg/L for rosuvastatin, lovastatin and simvastatin, respectively), trueness (98.8–101.7%), precision (<2.7%), carry-over effect, robustness, and stability. Values were inside the acceptance criteria of the Methods, Method Verification and Validation, Food and Drug Administration-Office of Regulatory Affairs, thus ensuring the reliability of the results. The main feature was the low proportion of organic solvent used, thus making the procedure sustainable and green. Besides, it was easy-to-conduct and with high sample-throughput, and then useful for routine analysis in pharmaceutical quality control. Finally, it was applied to commercial pharmaceutical preparations

Determination of Paroxetine in Pharmaceutical Preparations Using HPLC with Electrochemical Detection

A reliable and sensitive high performance liquid chromatographic method for the determination of widely prescribed antidepressant has been developed. Paroxetine is a potent selective serotonin reuptake inhibitor used for the treatment of depression and various mood disorders. The optimum mobile phase was prepared using a combination of 40% acetonitrile and phosphate buffer 0.01 M to pH 3 and running under isocratic mode at a flow rate of 1.0 ml/min. with electrochemical detection at 0.9V. The applicability of the developed method is in the field of quality control as well as for monitoring the level of drug at various concentrations during synthesis of the parent drug. The suggested methodology was validated following the guidelines of the FDA in terms of: sensitivity (LOD and LOQ, 0.005 and 0.01 ng/mL, respectively), linearity between 0.5 - 50 ng/mL (r2 > 0.9999), inter- and intraday precision (< 0.259% and < 0.538%), robustness (less than 5.0%) and recovery (99.7 - 100.7%). The developed method is specific, rapid (less than 10 min), precise, reliable, accurate, cheap and suitable for routine analysis for the determination of paroxetine in pharmaceutical preparations

A survey based on the use of imidacloprid on green leafy vegetables in remotely located Sagar, India

The low literacy level of the vegetable growers in the selected region of India is responsible for the use of highly toxic organophosphate pesticides on green leafy vegetables. Although in the Indian market imidacloprid (less toxic) is available but due to its high price and less effectiveness compared to that of organophosphates is not preferred to control pests on green leafy vegetables. The present research is a survey-based study designed to know the insecticide management practice among insecticide dealers, vegetable growers and comparison of obtained information with chromatographic results. The combination of survey and instrumental method (micellar liquid chromatographic technique) was utilized to determine whether the information collected from vegetable growers and insecticide dealers were similar and signicantly correlated with analytical data or not. Among the selected 48 samples of green leafy vegetables, imidacloprid was detected only in 6 samples. The survey of the insecticide dealers and vegetable growers conrmed that the vegetable growers used toxic organophosphates pesticides instead of less toxic imidacloprid. Survey data collected from vegetable growers and pesticide dealers were also tested by chromatographic method and a signicant correlation was found between them, which clearly demonstrates the minimum use of safe insecticide (imidacloprid). Imidacloprid insecticide was detected on green leafy vegetables after a preliminary survey of vegetable growers and pesticide dealers. Survey results revealed the use of potentially harmful pesticides other than imidacloprid which are banned from using in vegetables. Analytical results showed signicantly less use of imidacloprid on green leafy vegetables

An Innovative Project to Strengthen and Improve the Knowledge Acquisition in the Degree in Chemistry Using e-Learning Tools

Comunicació presentada a EDULEARN2018, 10th International Conference on Education and New Learning Technologies (July 2-4, 2018, Palma, Mallorca, Spain).The subject "Chemistry II (QU910)" is taught at first academic year (second semester) of the Degree in Chemistry at the University Jaume I. Some of its specific and general competencies are selflearning and writing and oral communication, regarding the main chemical concepts: chemical reactions, elements of the periodic table and calculations of the concentrations of the formed products and the remaining reagents in acid/base, complex, precipitation and redox reactions. We have noticed that 65% of the students have not studied any chemistry subjects (or only one) in High School or Professional Training before undertaking the Degree in Chemistry. The present project aims firstly to help these students to overcome their lack of background, secondly to compare the academic results of the students with and without previous contact with chemistry and finally, to establish actions to solve this prejudicial situation. This objective was reached by the implementation of a zero course, a course including the basic content of chemistry taught in the last years of High School, the month before the beginning of the first academic year. After the first year, students having attended chemistry before university obtained only 0.75/10 points more than the others. The Virtual Classroom, the emails and tutorial played an important role in the achievement of this zero-course

An easy and green assay to determine albendazole and ivermectin in veterinary preparations by micellar liquid chromatography

A procedure to determine albendazole and ivermectin in veterinary formulations, like tablet, bolus, oral suspensions, and injections by micellar liquid chromatography, has been developed. Sample preparation was a batch solid-to-liquid extraction in mobile phase, consisting of a stirring step (15 min), followed by ultrasonication (15 min) and filtration of the obtained supernatant, to reach a target concentration of 2 mg/L for both analytes. Using a mobile phase of 0.15 M sodium dodecyl sulfate—6% 1-pentanol buffered at pH 3 with a 0.01 M phosphate salt, running at 1 mL/min through a C18 column, both drugs were resolved in less than 10 min. Absorbance detection wavelength was 292 nm. Procedure was validated by the guidelines of the International Council on Harmonization in terms of specificity, calibration range (0.025–5 mg/L), trueness (97.8%–102.6%), precision (<2.2%), and system suitability. The method was found easy-to-handle, low cost, safe, green, and with high sample-throughput, thus useful for routine analysis. Therefore, it represents a valuable alternative for quality control of veterinary formulations. It was applied to samples of veterinary formulations purchased from local chemists and veterinarians, and label claims were inside the acceptance criteria (95%–105%)

Optimization and Validation of a Chromatographic Method for the Quantification of Isoniazid in Urine of Tuberculosis Patients According to the European Medicines Agency Guideline

Isoniazid is a drug that is widely used against tuberculosis. However, it shows high interpatient variability in metabolism kinetics and clinical effect, which complicates the prescription of the medication and jeopardizes the success of the therapy. Therefore, in a specific patient, the pharmacokinetics of the drug must be elucidated to decide the proper dosage and intake frequency to make the drug suitable for therapeutic drug monitoring. This can be performed by the quantification of the drug in urine as this process is non-invasive and allows the effects of long-time exposure to be inferred. The paper describes the development of a micellar liquid chromatographic method to quantify isoniazid in urine samples. Extraction steps were avoided, making the procedure easy to handle and reducing the waste of toxic organic solvents. Isoniazid was eluted in less than 5 min without interference from other compounds of the urine using a mobile phase containing 0.15 SDS–12.5% 1-propanol (v/v)–Na2HPO4 0.01 M buffered at pH 7, running at 1 mL/min under isocratic mode through a C18 column with the detection wavelength at 265 nm. The method was validated by following the requirements of the Guidelines on Bioanalytical Method Validation issued by the European Medicines Agency (EMA) in terms of selectivity, calibration curve (r2 = 0.9998 in the calibration range (0.03–10.0 μg/mL), limit of detection and quantification (10 and 30 ng/mL respectively), precision (<16.0%), accuracy (−0.9 to +8.5%), carry-over, matrix effect, and robustness. The developed method was applied to quantify isoniazid in urine samples of patients of an Indian hospital with good results. The method was found to be useful for routine analysis to check the amount of isoniazid in these patients and could be used in its therapeutic monitoring