Simple Method For Determination Research Articles

W247 A simple and robust mass spectrometric method for simultaneous determination of antidiabetic, antihypertensive, antidepressive, analgesic and antihyperlipidemic drug levels

W247 A simple and robust mass spectrometric method for simultaneous determination of antidiabetic, antihypertensive, antidepressive, analgesic and antihyperlipidemic drug levels

Indirect Spectrophotometric Determination of Mebendazole Using Methyl Orange Dyein the Presence of the Oxidizing Agent NBS

Aim: To develop a swift , simple, accurate and sensitive spectrophotometric method for determination of mebendazole (MBZL) in pure and pharmaceutical formulations. Methods: The suggested method depend on oxidation of MBZL with known excess amount of N-bromosuccinimide ( NBS ) in acidic medium and after reaction is insured to be complete , the surplus NBS is estimated by de colorization of methyl orange (MO) dye and measuring the absorbance of surplus dye at 508 nm. A linear calibration curve was obtained over the concentration range 2.5– 25 μg.ml-1 with correlation coefficient of 0.9997. The molar absorptivity and sandell's sensitivity index values were determined to be 1.505 × 104 L.mol-1.cm-1 and 0.019607 μg.cm-2. The limit of detection (LOD) and quantification (LOQ) were calculated to be 0.3736 and 2.553 μg.ml-1, respectively. The proposed method has been successfully applied to the determination of MBZL in available dosage form, the validity proposed method was confirmed by recovery study via standard addition technique . Keywords: mebendazole ; N-bromosuccinimide ; Determination ;Spectrophotometry ; methyl orange

Bulid-up a flow injection analysis unit for ammonium determination in the Shatt Al-Arab water

A Semi- automated flow injection analysis (FIA) unit was build-up for determination of ammonium ion in water samples from the Shatt Al-Arab River during the period from October 2009 to September 2010. The ammonium concentrations in water have been measured, at each of the eight stations (Qurnah (Tigres), Qurnah (Euphrates), Saad Bridge, Garmat Ali, Ashar, Abu Al-Khaseeb, Al-Seeba and Fao), monthly. The results indicated that (NH4+) concentrations increasing during May, June and July, 2010 especially in stations 5 and 6 were 0.95, 1.35 µg/ml , 1.30, 1.25 µg/ml and 1.45, 1.40 µg/ml, respectively. The FIA unit was applied successfully for the determination of ammonium in Shatt Al-Arab water sample and provide simple, fast, and reproducible methods for ammonium determination in water.

A simple method for simultaneous determination of organophosphate esters and their diester metabolites in dairy products and human milk by using solid-phase extraction coupled to liquid chromatography-tandem mass spectrometry.

Organophosphate esters (OPEs) and their diester metabolites have been frequently found in various environmental matrices and regarded as emerging environmental pollutants, whereas data on their occurrence in foods and human matrices are still limited. In this study, a novel and simple procedure was developed to simultaneously determine 14 OPEs and 6 diester metabolites in dairy products and human milk. After enzymatic hydrolysis by β-glucuronidase/arylsulfatase, a freeze-dried milk sample was extracted with acetonitrile and purified by solid-phase extraction. Subsequently, all target compounds were determined by HPLC-ESI-MS/MS. Linearity, limits of detection (LODs), recovery, precision, and matrix effects of the proposed methodology were validated, and the parameters of HPLC-ESI-MS/MS were optimized. LODs for OPEs and their diester metabolites were from 0.001 to 0.02 ng/mL, and limits of quantification (LOQs) were 0.01-0.3 ng/mL. Average recoveries at two spiked levels ranged between 67.3 and 121%, with relative standard deviation lower than 20.7%. A test for matrix effects showed that most analytes presented signal suppression, and isotopically labeled ISs were essential for compensating for the matrix effects. Finally, OPEs and their metabolites both showed high detecting frequencies in real samples, which indicated that these emerging pollutants were ubiquitous in foods and the human body, and the impact of the diester metabolites on population exposure must be included in exposure assessment.

Spectrophotometric Methods for Determination of Dopamine Hydrochloride in Bulk and in Injectable Forms

Two highly simple, economical, accurate and sensitive spectrophotometric methods for determination of dopamine hydrochloride (DAH) in either pure form and pharmaceutical formulations are described. The first method is based on determination of (DAH) spectrophotometrically at maximum absorbance 280 nm (method A). The second one is based on reduction of alkaline KMnO4 by (DAH) leading to the formation of green manganate species which are measured at 610 nm (method B). Under optimized conditions, the calibration graphs were linear in the range of 3.793 – 45.513, 0.190 – 4.362 μg.mL−1 of (DAH) for methods A and B respectively. The developed methods were successfully applied for the determination of dopamine hydrochloride in pharmaceutical samples.

Hemin loaded Zn−N–C single-atom nanozymes for assay of propyl gallate and formaldehyde in food samples

Single-atom nanozymes (SAzymes) show distinct advantages in catalytic activity and selectivity owing to their stability and special characteristic of maximum atomic utilization. Inspired by the structure of natural horseradish peroxidase (HRP), we developed a simple method for specific determination of both propyl gallate (PG) and formaldehyde (HCHO) by utilizing the intrinsic peroxidase mimics activity of hemin (hem) loaded Zn–nitrogen–carbon single-atom nanozymes (Zn–N–C@hem SAzymes). Zn–N–C@hem was prepared via a salt-template strategy and self-assembly, where hemin exhibits enhancing peroxidase-like activity can catalyze oxidation of colorless PG to yellow product. Upon introduction of HCHO into Zn–N–C@hem/PG system, complete suppression of PG oxidation was showed, resulting in distinguished decrease in absorbance. The colorimetric sensors of PG and HCHO based on Zn–N–C@hem/PG were developed at their respective linear range of concentration 1.25–200 mg/kg and 5–250 mg/kg. The practicability of the rapid analysis of PG and HCHO in food samples has been verified with reliable results.

Development and validation of HPLC method for simultaneous determination of Ketotifen Fumarate and Salbutamol Sulfate in bulk and tablets dosage forms

The aim of the study was to develop and validate a new, rapid, sensitive, simple, accurate and reproducible HPLC method for simultaneous determination of ketotifen fumarate and salbutamol sulfate. Simultaneous HPLC method was developed using RP-C18 stainless steel analytical column 4.6×150 mm C18.Acetonitrile and phosphate buffer pH 4 (30 : 70) were used as mobile phase and wavelength was adjusted to 276 nm for detection of drugs. Developed method was validated for its specificity, accuracy, precision, linearity and robustness. Method was also applied to quantify drugs in commercial tablets. Chromatogram obtained by newly developed method for simultaneous determination of two anti-asthmatic drugs, having well distinguished peaks for both drugs. Retention time of ketotifen fumarate and salbutamol sulfate were 2.69 minutes and 9.47 minutes respectively. Total run time for both anti-asthmatic drugs was 12 minutes. Limit of quantification for ketotifen fumarate and salbutamol sulfate was 1 ng/ml and 1.50 ng/ml respectively. Limit of detection of ketotifen fumarate and salbutamol sulfate was 3.03 and 4.54 respectively. A simple, easy, precise and new method was developed for simultaneous quantification of frequently used anti-asthmatic drugs. Developed method may prove effective and beneficial in determination of ketotifen fumarate and salbutamol sulfate in bulk and other pharmaceutical dosage forms.

Two Green Micellar HPLC and Mathematically Assisted UV Spectroscopic Methods for the Simultaneous Determination of Molnupiravir and Favipiravir as a Novel Combined COVID-19 Antiviral Regimen.

Following the spread of the COVID-19 pandemic crisis, a race was initiated to find a successful regimen for postinfections. Among those trials, a recent study declared the efficacy of an antiviral combination of favipiravir (FAV) and molnupiravir (MLP). The combined regimen helped in a successful 60% eradication of the SARS-CoV-2 virus from the lungs of studied hamster models. Moreover, it prevented viral transmission to cohosted sentinels. Because both medications are orally bioavailable, the coformulation of FAV and MLP can be predicted. The developed study is aimed at developing new green and simple methods for the simultaneous determination of FAV and MLP and then at their application in the study of their dissolution behavior if coformulated together. A green micellar HPLC method was validated using an RP-C18 core-shell column (5 μm, 150 × 4.6 mm) and an isocratic mixed micellar mobile phase composed of 0.1 M SDS, 0.01 M Brij-35, and 0.02 M monobasic potassium phosphate mixture and adjusted to pH 3.1 at 1.0 mL min−1 flow rate. The analytes were detected at 230 nm. The run time was less than five minutes under the optimized chromatographic conditions. Four other multivariate chemometric model methods were developed and validated, namely, classical least square (CLS), principal component regression (PCR), partial least squares (PLS-1), and genetic algorithm–partial least squares (GA–PLS-1). The developed models succeeded in resolving the great similarity and overlapping in the FAV and MLP UV spectra unlike the traditional univariate methods. All methods were organic solvent-free, did not require extraction or derivatization steps, and were applied for the construction of the simultaneous dissolution profile for FAV tablets and MLP capsules. The methods revealed that the amount of the simultaneously released cited drugs increases up until reaching a plateau after 15 and 20 min for FAV and MLP, respectively. The greenness was assessed on GAPI and found to be in harmony with green analytical chemistry concepts.

Chemical fingerprinting, quantification, and antioxidant activity evaluation of Osmanthus fragrans (Thunb.) Lour. Flowers by UPLC-ECD

ABSTRACT Osmanthus fragrans (Thunb.) Lour. flowers are important natural resource of phenolic compounds, which have antioxidant activities and have been consumed as functional food and dietary supplements for thousand years. Ultra-performance liquid chromatography coupled with electrochemical detection (UPLC-ECD) was developed to simultaneously analyze the eight phenolic compounds in Osmanthus fragrans flowers collected from different regions across China. The UPLC-ECD fingerprint was established for identification and comprehensive quality control. The antioxidant capacities of Osmanthus fragrans flowers were evaluated, and results were compared with those spectrophotometric antioxidant methods. A highly positive relationship was confirmed between the total peak area of characteristic components in chromatogram and the antioxidant potential determined by spectrophotometry with correlation coefficient greater than 0.80 (p < .01). Grey relational analysis showed that acteoside had the highest degree of correlation with antioxidant capacity. These results provided evidence to support the use of UPLC-ECD as a simple, rapid, and reliable method for electroactive phenolic component determination and antioxidant capacity quantification in vitro system.

Simultaneous analysis of free phytosterols and phytosterol glycosides in rice bran by SPE/GC–MS

In this study, free phytosterols and phytosterol glycosides in rice bran were successfully separated and analyzed using solid-phase extraction (SPE) combined with gas chromatography–mass spectrometry (GC–MS). The results showed that free phytosterols in rice bran included ergosterol (129 ± 8 μg/g rice bran), campesterol (126 ± 9 μg/g rice bran), stigmasterol (106 ± 9 μg/g rice bran), β-sitosterol (305 ± 10 μg/g rice bran), cycloartenol (80.5 ± 3.9 μg/g rice bran) and 24-methylenecycloartenol (87.1 ± 2.2 μg/g rice bran), while phytosterol glycosides included campesterol glucoside (16.0 ± 1.3 μg/g rice bran), stigmasterol glucoside (99.0 ± 4.9 μg/g rice bran) and β-sitosterol glucoside (133 ± 7 μg/g rice bran). The methodological validation indicated that this method could accurately quantify free phytosterols and phytosterol glycosides in rice bran. This study provided a new direction to establish a rapid and simple method for the simultaneous determination of different forms of phytosterols in foods.

Агаар дахь радон, түүний задралын бүтээгдэхүүнийг судалсан тухай

The simple method for determination of RaA, RaB and RaC in air by alpha counting of air filters was described. Diurnal variation of radon equilinrium equivalent concentration in outdoor air at some city Mongolia is observed.

NEW VALIDATED STABILITY-INDICATING RP-HPLC METHOD FOR THE SIMULTANEOUS DETERMINATION OF METFORMIN HYDROCHLORIDE, LINAGLIPTIN AND EMPAGLIFLOZIN IN BULK AND PHARMACEUTICAL DOSAGE FORMS

Objective: The purpose of the present study is to develop simple, fast, accurate, precise, and robust stability-indicating reverse phase high-performance liquid chromatographic (RP-HPLC) method for the simultaneous determination of metformin HCl, empagliflozin, and linagliptin in their combinations. Methods: Separation was performed on Agilent Eclipse XDB-C18 (250 mm x 4.6 mm, 5 µm) column with a mobile phase consisting of 0.1 % triethylamine (pH =3) buffer and acetonitrile in the ratio 40: 60 (v/v) at a flow rate of 1 ml/min. Detection of the analytes was carried out at a wavelength of 240 nm with a photodiode array detector. The developed method was validated as per the International Conference on Harmonization (ICH) guidelines. Results: The retention time values under the optimized condition were 2.660 min, 3.586 min, and 5.412 min for metformin HCl, linagliptin, and empagliflozin, respectively. The method was linear over a concentration range of 100 µg/ml-1500 µg/ml, 0.5 µg/ml-7.5 µg/ml, and 2.5 µg/ml-37.5 µg/ml for metformin HCl,linagliptin and empagliflozin respectively. The limit of detection (LOD) of the method was found to be 4.00 µg/ml, 0.02 µg/ml, and 1.00 µg/ml for metformin HCl, linagliptin, and empagliflozin, respectively. The degradation peaks were clearly resolved from the parent drug peaks in the chromatograms of forced degradation studies. Conclusion: The validated method was successfully applied for the determination of metformin HCl, linagliptin, and empagliflozin in their combined tablet dosage forms and hence can be used for the routine quality control of the drugs in pharmaceutical bulk, and dosage forms.

Development of Improved High-Performance Liquid Chromatography Method for the Determination of Residual Caprylic Acid in Formulations of Human Immunoglobulins.

Quality control of human immunoglobulin formulations produced by caprylic acid precipitation necessitates a simple, rapid, and accurate method for determination of residual caprylic acid. A high-performance liquid chromatography method for that purpose was developed and validated. The method involves depletion of immunoglobulins, the major interfering components that produce high background noise, by precipitation with acetonitrile (1:1, v/v). Chromatographic analysis of caprylic acid, preserved in supernatant with no loss, was performed using a reverse-phase C18 column (2.1 × 150 mm, 3 μm) as a stationary phase and water with 0.05% TFA–acetonitrile (50:50, v/v) as a mobile phase at a flow rate of 0.2 mL/min and run time of 10 min. The developed method was successfully validated according to the ICH guidelines. The validation parameters confirmed that method was linear, accurate, precise, specific, and able to provide excellent separation of peaks corresponding to caprylic acid and the fraction of remaining immunoglobulins. Furthermore, a 24−1 fractional factorial design was applied in order to test the robustness of developed method. As such, the method is highly suitable for the quantification of residual caprylic acid in formulations of human immunoglobulins for therapeutic use, as demonstrated on samples produced by fractionation of convalescent anti-SARS-CoV-2 human plasma at a laboratory scale. The obtained results confirmed that the method is convenient for routine quality control.

A simple and rapid chromatographic method for determination of naproxen and nabumetone in tablets

AbstractA simple, rapid, and cost‐effective chromatographic method for determination of naproxen and nabumetone using a guard column was developed. Factors affecting separation (i.e., types of stationary phase and types and compositions of mobile phase) were optimized. Naproxen and nabumetone were completely resolved (Rs &gt; 2.0) on a C18 guard column (10 × 4.0 mm, 5 μm) in 5 min using a mobile phase consisting of 2% v/v acetic acid (in water) and acetonitrile (75:25 v/v). Method validation was performed in terms of specificity, range, linearity, precision, and accuracy. The method showed a linear relationship (r2 &gt; 0.999) in a range of 2–30 μg/mL, good precision (%RSD &lt; 0.97), accuracy (%recovery of 98.8–100.5%), and specificity (peak purity indices &gt;99%) for the determination of naproxen and nabumetone. The method was applied for quantitation of naproxen and nabumetone in tablets. Results were complied with the United State Pharmacopeia 2021 limits (90.0–110.0 and 95.0–105.0% for naproxen and nabumetone, respectively). The use of the guard column proved to be efficient, fast, and economical due to less solvent consumption and waste production. In addition, this approach benefits the quality control of pharmaceuticals in less industrial countries with limited resources.

Front Cover: Clozapine and norclozapine monitoring in plasma following surfactant assisted dispersive liquid–liquid microextraction

DOI: 10.1002/jssc.202100068 The cover picture shows a surfactant-assisted dispersive liquid-liquid microextraction coupled with HPLC-UV as a fast and simple method for simultaneous determination of clozapine and norclozapine in a small amount of plasma sample. The analytical performance of the method was acceptable with a wide linear dynamic range (6.25-1600 ng/mL) covering the therapeutic range, toxic concentrations, and trace amounts, low limit of quantifications of 0.9 and 0.4 ng/mL for clozapine and norclozapine, respectively, as well as acceptable extraction ratios of 82.9% and 86.2% for clozapine and norclozapine, respectively.

Electrothermal Desolvation-Enhanced Dielectric Barrier Discharge Plasma-Induced Vapor Generation for Sensitive Determination of Antimony by Atomic Fluorescence Spectrometry.

A novel simple electrothermal desolvation-enhanced dielectric barrier discharge plasma-induced vapor generation (ETD-DBD-PIVG) method has been developed for sensitive Sb determination by atomic fluorescence spectrometry (AFS). In our proposed ETD-DBD-PIVG, 20 μL sample solution was dried first; then, the resulting solution residue was directly converted into molecular volatile species efficiently through the interactions with hydrogen-doped DBD plasma; and finally, it was transported to AFS for detection. It was found that the desolvation process could greatly enhance Sb vapor generation, and the Sb fluorescence signal intensity is almost independent of its speciation, where comparable sensitivity is achieved for Sb(III) and Sb(V), enabling efficient total Sb detection without pre-reduction. Influencing parameters were evaluated in detail, including heating time, discharge gap, solution pH, and flow rates of argon and hydrogen, as well as coexisting ion interference. Under optimized conditions, the limit of detection was calculated as 0.86 μg L-1 (17.2 pg) for Sb. The accuracy of the proposed method was validated by the analysis of certified reference materials of simulated natural water samples and several river water samples. Compared with conventional hydride generation, the new ETD-DBD-PIVG offers an alternative green vapor generation technique with several advantages: (1) it eliminates the use of a sample flow system (e.g., no use of any syringe or peristaltic pump); instead, 20 μL of a sample is directly pipetted onto the glass plate for analysis; (2) it greatly simplifies the sample pretreatment steps as no pre-reduction process is needed; (3) it is sensitive and suitable for volume-limited sample analysis: efficient Sb vapor generation without chemical reducing reagents in ETD-DBD-PIVG enables Sb detection with an absolute limit at the picogram level. All the results demonstrate that the proposed method provides a simple, green, and sensitive method for Sb determination and it can also be extended to other elements such as Cd and As.

A simple and rapid HPLC method for determination of S-allyl-L-cystein and its use in quality control of black garlic samples

The determination of S-allyl-L-cystein (SAC) in black garlic samples by high-performance liquid chromatography coupled with DAD was studied. A simple hand shaken water extraction of SAC from black garlic samples was derivatized with dansyl chloride at room temperature for 15 min. The rapid isocratic elution with a mobile phase of 45% sodium acetate buffer pH 5 and 55% methanol in a Poroshell C-18 column provided a retention time of 5.8 min for SAC resulted in 12 min analysis time in an autosample. A calibration curve from 1 to 40 μg/mL SAC was constructed with a coefficient of determination (R2) 0.998. The precision was less than 5.1% rsd (n = 8) and the accuracy in terms of recovery was between 84.7 and 96.8% (n = 3). The determined SAC in black garlic samples sold in Thailand using this method was between 27.7 and 393.4 μg/g. The proposed method was proved to be a promising method for quality control of black garlic samples.

Green, simple analytical method for biogenic amines determination in fruit juice samples using salting-out assisted liquid-liquid microextraction and gas chromatography-mass spectrometry

Salting-out assisted liquid-liquid microextraction (SALLME) was integrated withthederivatization procedure to establish a one-step sample pre-treatment approach for rapid analysis of14 biogenic amines (BAs) in fruit juices. The methodology consists of salting-out ofanalytes,derivatization with ethyl chloroformate (ECF), extraction with ethyl acetate (EtAc), andtheanalysis of the derivatized BAs using gas chromatography-mass spectrometry (GC–MS). Optimization oftheSALLME parameters, including the amount of sample, NaOH, and ECF was carried out through a Box-Behnken response surface design. The developed method exhibits satisfactory limits ofdetection (from 1.5 to 8.1 µg/L) andquantification (from 5.0 to 26.7 µg/L), and average recoveries between 84% and 108%. The developed procedure was used for BAs determination injuices ofdifferent berries withthe highest determined concentrations found for cadaverine, putrescine, tryptamine, andtyramine. Both GAPI and AGREE tools were used to assess the green character of the SALLME-GC–MS procedure.

Spectrophotometric determination of sulphite and thiamin hydrochloride via Xylenol orange dye

a simple, acurate and rapid spectrophotometric method for determination of sulphite and thiamine hydrochloride (B1) is described. This method used proton transfer reaction between sulphite ion with xylenol orange at pH(7.6) to develop red colour adduct that of maximum absorption at 580 nm. This adduct was used for determination of thiamine hydrochloride by bleaching the red colour product (xylenol orange-sulphite) at the optimum conditions established for the determination of sulphite. Beer’s law is obeyed in the concentration range (10-1000) μg/25ml (i.e. 0.4-40) of sulphite and 10-2000, μg/25ml (i.e. 0.4-80) for thiamine hydrochloride at the selected wavelength, the molar absorbtivity 2.8×104 l.mol-1.cm-1 for SO32- and 2.69×104 l.mol-1.cm-1 for thiamine hydrochloride, Sandell's index for sensitivity 0.002857 μg .cm-2 for sulphite and 0.012537 μg .cm-2 for B1. Good recoveries of sulphite and thiamine hydrochloride from water samples and pharmaceutical formations are achieved using the proposed method.

A 96-Well Plates-based UV Spectrophotometric Assay for Determination of Total Glucosinolates in Isatis indigotica Roots

Background: Glucosinolates (GLS) are important secondary metabolites in Cruciferae vegetables and herbs. Currently, the assays of total GLS determination are cumbersome (requiring acidic or enzymatic hydrolysis and addition of staining reagents), time-consuming, and indirect. High concentrations of inorganic salts are inevitably incorporated into the GLS products during separation. There is a need for a quantitative method for simple and rapid determination of total GLS after desalting process. Methods: A 96-well plates-based UV spectrophotometric method for determination of total GLS of Isatis indigotica roots was developed in the present study. The detection wavelength is set at 230 nm using quartz plates. This assay was validated using gluconapin and sinigrin as reference standards, and applied to determine the total GLS of I. indigotica roots prepared from five different desalting methods. Results: This assay is specific for total GLS prepared from I. indigotica roots, and it has acceptable accuracy (91.76–98.18% for quality control, and 95.59–102.52% for addition/recovery), precision (0.24–0.70% pooled RSD), reproducibility (0.31–1.84% RSD), and stability (0.24–1.45% RSD) over a 72-h period. Conclusion: The 96-well plates-based UV spectrophotometric assay is simple and accurate for high-throughput determination of total GLS.