Percent Relative Standard Deviation Research Articles

A new sensitive layer based on clcinated Zn/Ti-MOF/magnetic molecularly imprinted polypyrrole: Application to preconcentration and electrochemical determination of perfluorooctane sulfonic acid by magnetic carbon paste electrode

In this research, a new approach based on magnetic electrodes has been developed for the determination of per-fluorooctane sulfonic acid (PSOF). Zinc and Titanium-based Metal-organic framework (MOF) was synthesized and used with polypyrrole as a conductive polymer for preparation of the absorbent to achieve the best performance for electrochemical application. The response of the electrode for determination of the PFOS was affected and optimized by different factors such as buffer solution, pH of the solution, amount of absorbent, extraction time of absorbent, accumulation time, as well as the Square Wave Voltammetry (SWV) instrumental parameters including voltage step, pulse amplitude, frequency and resting time. In the optimum condition, the response of the Zn/Ti/C-MOF-magnetic molecular imprinting polymer/carbon paste electrode (MOFMMIP/CPE) has increased logarithmically by increasing the concentration in the range of 0.002–165 μM by the limit of detection (LOD) of 0.7 nM. The obtained percentage of Recovery (96.00–104.14 %), Bias (–4.00 - 4.14 %) and Relative Standard Deviation (RSD) (1.89–3.74 %) for determination of the PFOS in real and spiked tap water, river water and well water samples demonstrates that the proposed method has an acceptable precision. The comparison between the gained data by the presented method and High-performance liquid chromatography (HPLC) showed that the presented method has high accuracy.

IDENTIFICATION, SEPARATION, AND CHARACTERIZATION OF DEGRADATION PRODUCTS OF TRIAMCINOLONE HEXACETONIDE USING LC AND LC-MS/MS

Objective: The study aimed to separate the forced degradation products of Triamcinolone hexacetonide using HPLC and characterize the degradation product by LC-MS/MS fragmentation pattern. Methods: Triamcinolone hexacetonide (THA) and its primary degradation products were identified using a liquid chromatography-mass spectrometry/Mass spectrometry (LC-MS/MS) approach. The degradation study was based on in-depth stress testing with acid, base, peroxide, heat, and light. A Zorbax SB C18 column and a greener mobile phase composed of methanol and 10 mmol ammonium acetate buffer in water at pH 3 were employed to accomplish separation and quantitation at a flow rate of 0.7 ml/min in an isocratic mode with a 239 nm detection wavelength. Results: A major degradation product of the drug was obtained in acidic and alkaline stress conditions. The drug was found to be stable for all other stress conditions. The LC-MS/MS analysis results of the active pharmaceutical ingredient and resulting product after degradation were interpreted to identify the novel degradation product and fragments. The developed method was validated as per International Council for Harmonization (ICH) guidelines. The square root of the correlation coefficients, which indicated linearity for THA in 50 to 150 % of the workload, was 0.99. Method Precision assay was performed on six different preparations, percentage relative standard deviation (% RSD) of assay value is 0.17 % and system precision is 0.30 %. In accuracy, overall % RSD of 50 %, 100 %, and 150 % in triplicate is 0.95. Conclusion: It is concluded that the drug is stable to all other stress conditions except for acidic and alkaline stress conditions and generates a novel degradation product. The developed LC (Liquid chromatography) method separates and identifies the degradation product.

Switchable metal extractant integrated miniaturized 3D-printed device: A semi-online multi-metal separation system for matrix-free ICP-MS analysis

BackgroundThis study tackles the critical challenges in metal analysis by presenting an innovative miniaturized metal extraction device prototype. This device features a functional nanocomposite (FNC) enhanced 3D-printed polylactic acid (PLA) metal extractant (FNC@3D PLA). The research is motivated by the constraints of traditional solid-phase extraction (SPE) methods, specifically their limitations in handling competitive metal ion environments and matrix interference during inductively coupled plasma mass spectrometry (ICP-MS) analysis. The designed prototype aims to overcome these challenges and enhance the extraction efficiency of diverse metals. ResultsThe FNC, designed to incorporate various functional groups critical for metal ion extraction efficiency, was meticulously engineered through the reaction of acid-treated and delaminated graphitic carbon nitride nanosheets (Thiol-gCN NSs) with 3-mercaptopropyl trimethoxysilane (MPTMS). The competitive metal ion extraction efficiency of FNC@3D PLA was demonstrated, showcasing notable limit of detection values of 3.2 ± 0.7 ng mL-1 and 8.57 ± 3.05 ng mL-1 for Cu and Ag, respectively. Furthermore, the miniaturized 3D-printed metal-preconcentration setup incorporating FNC@3D PLA exhibited favorable intraday relative standard deviation (RSD) percentage (%) values ranging from 1.23 to 8.6 for both Cu and Ag. Interday RSD % between 1.41 and 8.14 were observed under spiked real urine sample conditions. The sustainability and robustness of the proposed approach were underscored by substantial recovery % values exhibited by FNC@3D PLA, even after eight consecutive regeneration processes. SignificanceThis study significantly contributes to the advancement of analytical methodologies by providing a reliable and efficient platform for metal extraction and preconcentration in practical metal analysis applications. Developed FNC@3D PLA system demonstrates its potential to address the challenges associated with SPE in metal analysis, especially in complex sample matrices. We believe implications of this research can be extended to various fields, from environmental monitoring to clinical diagnostics, where accurate and reliable metal analysis is paramount.

Determination of phenytoin at trace levels in domestic wastewater and synthetic urine samples by gas chromatography-mass spectrometry after its preconcentration by simple liquid-phase microextraction.

This work presents a sensitive and accurate analytical method for the determination of phenytoin at trace levels in domestic wastewater and synthetic urine samples by gas chromatography-mass spectrometry (GC-MS) after the metal sieve-linked double syringe liquid-phase microextraction (MSLDS-LPME) method. A metal sieve was produced in our laboratory in order to disperse water-immiscible extraction solvents into aqueous media. Univariate optimization studies for the selection of proper extraction solvent, extraction solvent volume, mixing cycle, and initial sample volume were carried out. Under the optimum MSLDS-LPME conditions, mass-based dynamic range, limit of quantitation (LOQ), limit of detection (LOD), and percent relative standard deviation (%RSD) for the lowest concentration in calibration plot were figured out to be 100.5-10964.2 μg kg-1, 150.6 μg kg-1, 45.2 μg kg-1, and 9.4%, respectively. Detection power was improved as 187.7-folds by the developed MSLDS-LPME-GC-MS system while enhancement in calibration sensitivity was recorded as 188.0-folds. In the final step of this study, the accuracy and applicability of the proposed system were tested by matrix matching calibration strategy. Percent recovery results for domestic wastewater and synthetic urine samples were calculated as 95.6-110.3% and 91.7-106.6%, respectively. These results proved the accuracy and applicability of the proposed preconcentration method, and the obtained analytical results showed the efficiency of the lab-made metal sieve apparatus.

Applicability of QbD-assisted Analytical Method for Simultaneous Detection of Tetrahydrocurcumin and Folic Acid in Developed Nanostructured

Aims:: Applicability of QbD-assisted analytical method for simultaneous detection of tetrahydrocurcumin and folic acid in developed nanostructured. background: Background: Diabetic foot ulcer (DFU), a multifactorial disorder involves chronic inflammation, oxidative stress and neuropathy. Current treatment therapies, involving the use of growth factors and skin substitutes being costly, are out of reach for the majority of patients. The present research explored the usefulness of (5929IN008, application number 202211045937) a combination of tetrahydrocurcumin and folic acid loaded nanostructured lipidic carriers. Background:: Diabetic foot ulcer (DFU) is a multifactorial disorder that involves chronic inflammation, oxidative stress and neuropathy. Current treatment therapies involving the use of growth factors and skin substitutes being costly, are out of reach for the majority of patients. The present research explored the usefulness of (5929IN008, application number 202211045937), a combination of tetrahydrocurcumin and folic acid-loaded nanostructured lipidic carriers. Objectives:: To develop and validate a QbD-assisted method for simultaneous analysis of tetrahydrocurcumin (THC) and folic acid (FA). Applicability of the above method to determine total drug content (TDC) and entrapment efficiency (EE) of nanostructured lipid carriers (NLCs) loaded THC and FA. Methods:: A high-performance liquid chromatographic (HPLC) method was developed, optimized and validated using Box-Behnken design for improved method performance. Chromatographic separation was conducted on a Supelco 250 x 4.6 mm (5 μm) column with optimized mobile phase composition containing tetrahydrofuran: citric acid buffer pH 3.5 (50:50) at a flow rate of 0.4 mL.min-1 and diode array detection between 210 and 360 nm. Results:: The method developed in a concentration range of 1 to 100 μg.mL-1 was found to be linear (R2 0.999, p≤0.001), accurate (99.10-101.70%) and precise with high recovery values in intra and inter-day results. The system adaptability and robustness evaluation revealed that the percent recovery ranged from 96.90 to 102.80%, and the percent relative standard deviation (%RSD) values were less than 2%. Moreover, the method was further applied for the determination of TDC (86±6% and 96±8%) and drug EE (81±21% and 73±13%) for THC and FA, respectively. Conclusion:: The investigation indicated the applicability of the developed and validated method for the estimation of THC and FA in the developed nanostructured lipidic carriers.

Analytical Method Development and Validation of a UV‐Spectrophotometric Technique for Pioglitazone HCL Estimation in Bulk and Polymeric Nanoparticles

AbstractThe type 2 diabetes drug pioglitazone is encapsulated in polymeric (Chitosan/PEG blended PLGA) nanoparticles utilizing solvent evaporation methods. The current research aimed to develop and validate an accessible, accurate, fast, and commercial UV spectrophotometric approach for assessing Pioglitazone in bulk and polymeric nanoparticles. In the estimation method that involves a pH 7.4 phosphate buffer, the maximum absorbance of Pioglitazone is reported to be 269 nm. With a correlation coefficient of 0.999, the drug exhibits linearity in the concentration series of 5–60 µg mL‐1. The proposed technique is validated as per ICH guidelines for linearity, accuracy, precision, and ruggedness. When the proposed technology is used in nano‐formulation, the percent amount of drug estimated to be 99.35% agreed well with the label claim. Recovery experiments at three distinct levels, 50%, 75%, and 100% are used to test the method's accuracy. The recovery rate is estimated to be between 98.91% and 99.11%. The low percent relative standard deviation (RSD) value indicates the method's accuracy and reproducibility. The method's repeatability, intraday, and interday precision are all examined. The approach is precise if the percent RSD value is less than 2. With the assistance of two analysts, the ruggedness of the suggested method is investigated. For the scheduled examination of Pioglitazone in bulk and polymeric nanoparticles, the above process has been developed and validated and proved to be a quick and cost‐effective quality‐control tool in pharmaceuticals.

Development of UV‐Vis spectroscopy-based analysis method for determination of tin(IV) in epilobium parviflorum (hoary willowherb) tea using deep eutectic solvent based preconcentration

In this study, a UV–Vis Spectroscopy-based method was developed for the determination of tin(IV) in epilobium parviflorum tea samples after preconcentration. The preconcentration process was carried out using the liquid-liquid microextraction technique. Before starting the analysis, optimization studies were carried out for the variables likely to affect the experimental results. As a result of the analyzes performed under optimum conditions, the detection limit of our method was calculated as 16.83 μg/L. The percent relative standard deviation value was calculated as 1.25% (n = 8) and linearity was found in the range of 10–1000 μg/L. Recovery experiments were performed on epilobium parviflorum tea samples using the matrix matching method. As a result of the analyzes made on teas belonging to three different brands, recovery results ranging from 92 to 117% were obtained.

Quantitative Applications of ATR-FTIR Spectroscopy with Chemometrics for the Estimation of Amikacin in Amikacin Sulphate Injections

Background: Amikacin belongs to the class of aminoglycoside antibiotics used in the treatment of gram-negative bacterial infections. It is resistant to the aminoglycosides modifying enzymes, making it a clinically effective drug in multidrug-resistant infections. Methods: In this study, a simple Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy was used for the quantification of amikacin in amikacin sulphate injection. The infrared spectra were generated in the spectral range of 4000–667 cm-1. The calibration curve was computed through TQ Analyst Pro edition software, and the partial least square regression analysis found the linearity in the range of 10-60% w/w. Results: The best calibration results were obtained in the spectral region from 1040 to 1020 cm-1 with a correlation coefficient (r2) of 1.000. The residual mean standard error (RMSEC) value was 0.00235. The percent relative standard deviation (%RSD) values for intra-day and inter-day precision were less than 8.0. The percent relative error (%RE) values were calculated and found in between the range of 0.52 to 5.60. The percent recovery of the amikacin estimation was 113.09 ± 4.27(n=3). Conclusion: This validated method is considered a green method, which is suitable for the routine analysis of amikacin in amikacin sulphate injections.

RP-HPLC METHOD DEVELOPMENT AND VALIDATION FOR QUANTITATIVE ESTIMATION OF TEMOZOLOMIDE AND (S) - PERILLYL ALCOHOL IN NANOPARTICULATE DOSAGE FORM

A quick reverse-phase high-performance liquid chromatography (RP-HPLC) approach for the quantitative measurement of temozolomide (TMZ) and (s) - perillyl alcohol [(S)-POH] in a nanoparticulate system was developed and validated in the current work. The RP-HPLC method for the simultaneous estimation of TMZ and (S)-POH was developed using Agilent (Infinity 1260) HPLC system and ZorbaxC18 (4.6 x 150 mm i.d., 5µ; Agilent) as stationary phase. The optimized mobile phase comprised of ACN: water: MeOH (42:12:46 V/V/V; 42:08:50 V/V/V and 20:30:50 V/V/V) pumped at a flow rate of 0.8 mL min-1, 0.8 mL min-1 and 1 mL min-1, respectively. Drug separation was accomplished in an isocratic mode, and a PDA detector operating at 210 nm was used to track elution. The procedure was validated in accordance with ICH-Q2R1 standards. The responses of TMZ and (S)- POH were found to be linear at 50-175 μg mL-1 (ACN: water: MeOH 42:12:46 V/V/V and 42:08:50 V/V/V) and 50-175 μg mL-1 (ACN: water: MeOH 20:30:50 V/V/V) respectively. The percent recovery was determined to be between 97% and 103%, demonstrating that the method’s accuracy was adequate. The precision study’s percent relative standard deviation (% RSD) was less than 2, indicating the accuracy of the suggested procedure. It was discovered that the established method for the quantitative determination of TMZ and (S)- POH in bulk and in hollow gold nanoparticles was accurate, precise, and specific. The developed technique can be applied to TMZ and (S)- POH routine testing and quality control in bulk and nanoparticulate systems.

Synthesis of Fe3O4@SiO2-creatine as a new nanosorbent for dispersive magnetic solid-phase microextraction of copper ions from water, food, and soil samples

For the first time, Fe3O4@SiO2-creatine (Fe3O4@SiO2-CRT) was synthesized and exploited as a nanosorbent in the dispersive magnetic solid phase microextraction (D-MSPμE) of copper from water, food, and agricultural soil samples. Flame atomic absorption spectrometry was employed for the quantification of concentration of Cu(II) ions subsequent to the elution process. Different techniques, including X-ray diffraction, fourier transform infrared, field emission scanning electron microscopy, and vibrating sample magnetometer, were utilized to characterize the synthesized nanosorbent. The factors influencing the efficiency of the extraction process were investigated and optimized. Under the optimal conditions (solution pH, 7.0; nanosorbent quantity, 20 mg; adsorption time, 7.0 min; desorption time, 2.0 min; and desorption agent, HNO3 0.5 mol L−1), the proposed method provided a wide linear range (5.0–125 ng mL−1) with a determination coefficient (R2) of 0.9991. The limit of detection, extraction recovery, and relative recoveries were obtained to be 1.50 ng mL−1, 98.1%, and 90.6–103%, respectively. The intra-day relative standard deviation percentages (n = 5) for different concentrations were in the range of 2.33–3.11%. The proposed method offers merits such as swiftness, high sensitivity, rendering it applicable to detect trace levels of copper (5.19–14.2 ng mL−1 or ng g−1) in water, food, and agricultural soil samples.

Low-cost electrochemical biosensor based on a multi-walled carbon nanotube-doped molecularly imprinted polymer for uric acid detection

Uric acid is a naturally occurring antioxidant that must be maintained in the human body at 1.49–4.46 mM to prevent hyperuricemia, which may lead in the formation of monosodium urate (MSU) and Lesch–Nyhan syndrome. The objective of this research is to examine molecularly imprinted polymers (MIP)-based non-enzymatic electrochemical sensors that simulate the biological mechanism of uricase oxidase. As an affordable working electrode, commercial pencil graphite electrode (PGE) was modified with multi-walled carbon nanotubes (MWCNTs) and polypyrrole. With a 1:10 uric acid to monomer ratio, 20 cycles of polymerization, 100 mV s−1 of polymerization rate, and 30 cycles of template removal, the optimum MIP was obtained. By employing differential pulse voltammetry (DPV) to detect the presence of uric acid over the range of 0.22–3.5 mM, the limit of detection (LOD) was determined to be 0.76 mM, with a sensitivity of 97.459 µA µM−1 cm−2. This sensor demonstrated good repeatability and reproducibility, with relative standard deviation percentage (%RSD) of 3.43 % (n = 10) and 5.37 % (n = 3), respectively, which maintains a performance stability of 71 % after 19 days of use. This sensor also detected uric acid with good selectivity, even in the presence of interfering molecules including K+, Na+, sarcosine, citric acid, ascorbic acid, glucose, and dopamine.

Chemical Stability of Lorazepam Oral Solution Repackaged in Plastic Oral Syringes at Room and Refrigerated Temperatures

Purpose: Generic lorazepam oral solution is supplied in a 30 mL multi-dose bottle requiring protection from light and refrigeration, with a beyond use date of 90 days once the bottle is opened. The repackaging of 1 mL doses of lorazepam oral solution into oral syringes allows for facilitated dispensing, yet no available data supports repackaging and storing lorazepam oral solution in syringes. The validation and application of a stability-indicating high-performance liquid chromatography with ultraviolet detection (HPLC-UV) method for the quantification of lorazepam allowed for the determination of the stability of lorazepam oral solution when stored in oral syringes. Methods: A stability-indicating HPLC-UV method was developed for the quantification of lorazepam in oral solution. The method was validated using guidance from USP < 1225 >. For the stability investigation, 2 mg/mL lorazepam oral solution was aliquoted into clear plastic oral syringes in 1 mLmilliliter doses from 2 multi-dose stock bottles and randomly allocated for storage in room temperature or refrigerated environment. Baseline lorazepam concentrations were measured on the day the study was initiated and designated as 100% initial concentration samples. Subsequent samples were analyzed in triplicate at time points of 24, 48, and 96 hours and 7, 10, 14, 21, 30, and 60 days. Results: The calibration curves on three non-consecutive days met the linearity criteria of R2 > 0.99. Inter- day and intra-day precision and accuracy (percent relative standard deviation and percent error) were ≤2% over three days. During the stability investigation, percent initial concentration of lorazepam from room and refrigerated syringes remained above 90% for the duration of the study. Conclusion: The stability-indicating HPLC-UV method was successfully applied to the investigation of lorazepam oral solution stability when stored in syringes at room and refrigerated temperatures. The emergent need for use of lorazepam concentrate for inpatients and the restrictions of how the medication is supplied necessitated a need for the evaluation of repackaging into unit dose syringes for immediate availability from automated dispensing cabinets. Lorazepam oral solution stored in clear plastic syringes maintained greater than 90% initial concentration at both room and refrigerated temperatures for 60 days.

In vitro bioaccessibility round robin testing for arsenic and lead in standard reference materials and soil samples.

In this study, we assessed the suitability of using a standard reference material (SRM) other than National Institute of Standards and Technology (NIST) 2710a or NIST 2711a in USEPA Method 1340 to determine arsenic (As) and lead (Pb) in vitro bioaccessibility (IVBA) and the capabilities of Canadian-based laboratories to perform the method. Five laboratories participated in an initial round robin study and analyzed NIST 2710a, NIST 2711a, BGS119, and Enviromat SS-2. Intra- and inter-laboratory variability were generally acceptable with percentage relative standard deviations (RSD) of less than 20%. The mean total As and Pb concentrations obtained for BGS119 (332 and 936 mg/kg, respectively) and the mean IVBA values (As = 14.3% and Pb = 78.1%) suggested it may be a suitable and acceptable SRM, whereas the concentration of As in Enviromat SS-2 as received (3.2 mg/kg) was deemed too low. Ten soil samples from sites with varying land use were analyzed in a follow-up round robin study using the modified IVBA method that included BGS119 as SRM. The concentrations of As and Pb in the IVBA extracts reported by the participating laboratories were comparable. The mean As IVBA values for the field-collected samples ranged from 0.1% to 56.4%; for Pb, they ranged from 7.0% to 121%. The lowest IVBA values were measured in mine site samples; the highest values were associated with smelter-affected soils. The low IVBA values correlated with high iron content. Intra- and interlaboratory reproducibility were acceptable (RSD < 30%). Based on the findings of the study, laboratories can use the modified method to provide reproducible and comparable As and Pb IVBA data. The use of BGS119 as an alternative SRM to assess contaminated sites in the province of British Columbia for regulatory purposes is recommended, as it is representative of As and Pb concentrations in contaminated soils in British Columbia. Integr Environ Assess Manag 2024;00:1-10. © 2024 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Development of a Stability Indicating UPLC Method for the Determination of Tirbanibulin in Bulk and Its Pharmaceutical Dosage Form.

The primary goal of this study was to create and validate a simple, precise, sensitive, and accurate ultra-performance liquid chromatography (UPLC) method for estimating tirbanibulin in pure and dosage form. A UPLC technique was developed using a Waters Acquity UPLC Phenyl (100 x 2.1 mm, 1.7 µm) column. The developed technique was validated in accordance with the International Conference on Harmonization (ICH) guidelines. Tirbanibulin was separated chromatographically with high resolution using the mobile phase acetonitrile: buffer (30:70 v/v) at 0.5 mL/min, 5 µL injection volume, and 220 nm wavelength. The validated technique was found to be linear in the 1-15 µg/mL range. The detection and quantification limits for tirbanibulin were 0.03 and 0.1 µg/mL, respectively. The percentage relative standard deviation was less than 2%, demonstrating the precision of the developed technique. Furthermore, the recovery rate was nearly 100%, confirming the accuracy of the method. Minor modifications to the chromatographic conditions demonstrated the robustness of the method. The developed analytical method was precise, simple, reproducible, and sensitive. Consequently, it can be used to determine tirbanibulin.

An Eco-Friendly RP-HPLC Method Development and Validation for Quantification of Favipiravir in Bulk and Tablet Dosage Form Followed by Forced Degradation Study.

In this work, an eco-friendly simple, precise reverse phase high-performance liquid chromatography (HPLC) method has been developed and validated for Favipiravir in bulk and tablet dosage form followed by its force degradation study. The proposed method was validated to obtain official requirements including stability, accuracy, precision, linearity, robustness and selectivity as per International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH) Guidelines. The estimation was developed on C (18) column reversed-phase using the mobile phase composition as methanol:water (10:90v/v). The flow rate was set as 1ml/min, and the maximum absorption was observed at 323nm using Shimadzu Photo Diode Array detector. The Favipiravir, drug showed a precise and good linearity at the concentration ranges of 10-50μg/mL. The Revearse Phase High Perforance Liquid Chromatography assay showed the highest purity ranging from 99.90 to 100.02% for Favipiravir, tablet dosage form, and 100.15% was the mean percentage purity. The percent recovery was found within the acceptance limit of (98.6-100.0%). Intra- and inter-day precision studies of the method were less than the maximum allowable limit percentage of relative standard deviation ≤ 2.0. The Favipiravir retention time was found to be 5.00min. To examine the stability of the drug, various forced degradation studies were conducted on Favipiravir Active Pharmaceutical Ingredient. The developed method was validated according to the ICH guidelines. A very quick, cost-effective, precise and accurate HPLC method for the determination of Favipiravir has been developed and validated in compliance with ICH guidance Q2.

A Green UPLC Method for the Simultaneous determination of Tenofovir and Amoxicillin in Biological Fluids and Dosage Forms

This paper elucidates the process of developing and validating the UPLC technique, aiming to enable the concurrent measurement of tenofovir and amoxicillin. This UPLC method is accurate and sensitive. The experimental setup involved utilizing a Kinetex 1.7μ C18 100A (2.1-mm × 50-mm) column maintained at a temperature of 30°C. The mobile phase employed a combination of methanol and phosphate buffer (0.1% orthophosphoric acid in water, pH 3.5) in a ratio of 30:70 (v/v). The flow rate was set at 0.2mL/min, and the detection wavelength for analysis was 230nm. All these conditions resulted in optimum chromatographic separation. This developed method of UPLC took less than 4 minutes to separate this mixture. The detection limits for two medications were determined to be 0.45µg/mL for tenofovir and 0.26µg/mL for amoxicillin. The calibration plots of both substances exhibited satisfactory linearity within the concentration range of 1.0 - 2.0 µg/mL. Remarkably, the method demonstrated excellent performance with high percentage recoveries ranging from 96.8% to 102.92% and low percentage relative standard deviation (%RSD) values below 2%. Consequently, the proposed methodology proved to be highly effective for detecting the targeted drugs in their respective dosage forms.

Chemometric method development for the determination of naringin and verapamil

BackgroundBy resolving complicated spectra from drug combinations, chemometric techniques are valuable for multi-component investigation. The capacity to properly estimate combinations of components without separating drugs from their mixture is one of the benefits of chemometric analysis approaches over traditional analytical methods. These approaches are easy to use and sensitive even to the lowest concentrations. They are also practical, affordable, and cost-effective. In the current study, the chemometric aided spectrophotometric approach was used to evaluate the two drugs naringin and verapamil. The approach is multidimensional and based on chemometrics, which includes an orthogonal partial least square method that is a new refinement of the partial least squares regression analysis method. With this technique, no conversions are made to the spectrum that overlaps the two drugs. The tools UV-PROBE, SIMCA version 17, and excel were used to process the chemometric data.ResultsAccording to results from an orthogonal partial least square model, the mean percent recovery and relative standard deviation for the combination of verapamil with naringin were 100.80/1.19 and 100.836/1.35, respectively.The calibration model was used to predict known synthetic mixtures.This method shows good consistency in recovery ranging between 98.92 and 103.59% for VER and from 96.21 to 101.84% NAR. As saying the synthetic mixture revealed that it had a high percentage of purity.ConclusionsThe proposed chemometric method can estimate the quantitative amount of pharmaceuticals based on their dosage forms. This approach meets the requirements for the international conference on harmonization's (ICH) analytical criteria, such as precision and accuracy.Graphical

Determination and Quantification of Acetaldehyde, Acetone, and Methanol in Hand Sanitizers Using Headspace GC/MS: Effect of Storage Time and Temperature.

Accurate determination of the concentration of alcohols and their metabolites is important in forensics and in several life science areas. A new headspace gas chromatography-mass spectrometry method has been developed to quantify alcohols and their oxidative products using isotope-labeled internal standards. The limit of detection (LOD) of the analytes in the developed method was 0.211 µg/mL for methanol, 0.158 µg/mL for ethanol, 0.157 µg/mL for isopropanol, 0.010 µg/mL for n-propanol, 0.157 µg/mL for acetone, and 0.209 µg/mL for acetaldehyde. The precision and accuracy of the method were evaluated, and the relative standard deviation percentages were found to be less than 3%. This work demonstrates the application of this method, specifically in quantifying the concentration of oxidative products of alcohol and other minor alcohols found in hand sanitizers, which have become an essential household item since the COVID-19 pandemic. Apart from the major components, the minor alcohols found in hand sanitizers include methanol, isopropanol, and n-propanol. The concentration range of these minor alcohols found in ethanol-based hand sanitizer samples was as follows: methanol, 0.000921-0.0151 mg/mL; isopropanol, 0.454-13.8 mg/mL; and n-propanol, 0.00474-0.152 mg/mL. In ethanol-based hand sanitizers, a significant amount of acetaldehyde (0.00623-0.231 mg/mL) was observed as an oxidation product, while in the isopropanol-based hand sanitizer, acetone (0.697 mg/mL) was observed as an oxidation product. The concentration of acetaldehyde in ethanol-based hand sanitizers significantly increased with storage time and temperature, whereas no such increase in acetone concentration was observed in isopropanol-based hand sanitizers with storage time and temperature. In two of the selected hand sanitizers, the acetaldehyde levels increased by almost 200% within a week when stored at room temperature. Additionally, exposing the hand sanitizers to a temperature of 45 °C for 24 h resulted in a 100% increase in acetaldehyde concentration. On the contrary, the acetone level remained constant upon the change in storage time and temperature.

Monolithic stationary phases prepared via cyclic anhydride ring-opening polymerization as tunable platforms for chromatographic applications.

Polymer monolithic stationary phases were prepared based on a cyclic anhydride as a reactive and tunable platform via ring-opening post-polymerization using primary amines, octadecylamine and benzylamine. The characterization techniques indicated the insertion of the functional groups into the original monoliths and confirmed the amidation reactions. The post-polymerization modification also improved the monolith's thermal and mechanical stability and induced significant improvement in their surface area. The stationary phases were synthesized inside small dimension stainless-steel columns (2.1 mm i.d. × 50 mm length). The prepared columns before and after modifications have been tested for the separation of the alkylbenzene series and some polycyclic aromatic hydrocarbons (PAHs) as model compounds. In all cases, the chromatographic performance in terms of the height equivalent to a theoretical plate on the functionalized monoliths was remarkably improved when compared with that on the unmodified monolith, which was between 9.59-39.49 μm and 4.08-31.50 μm using monoliths modified with octadecylamine and benzylamine, respectively. Under the same chromatographic conditions, the functionalization of monoliths with octadecylamine provided more hydrophobic interactions and enhanced the retention of alkylbenzenes, while the modification of monoliths with benzyl groups improved the separation and the retention of the PAHs through the strong π-π interactions. However, post-modification polymerization with octadecylamine and benzylamine enhanced the separation efficiency of the prepared columns toward all studied compounds. The repeatability of the injections on the same column and the reproducibility of the prepared columns have been studied for some selected parameters and estimated in terms of percent relative standard deviation (%RSD) for some of the studied compounds. The repeatability of the prepared columns was ≤9.42% (n = 5) based on run-to-run injections and ≤9.48% based on day-to-day injections for five successive days. The reproducibility levels, on the other hand, were ≤20.95% for all studied parameters in all cases. To assess their performance for the analysis of real samples, the applicability of the prepared columns was examined for the separation of the active ingredients extracted from some commercial pharmaceutical formulations and for the separation of tea water extract constituents. The validation data show the suitability of the columns for practical use in the routine analysis of these samples.

Determination of copper ion at trace levels in apple tea samples by simultaneous complexation and spray assisted microextraction method prior to detection by flame atomic absorption spectrophotometry

In the present study, a green and sensitive analytical method for the determination of copper ion at trace levels in apple tea samples was developed. Simultaneous complexation/extraction of the analyte were achieved by spraying-based fine droplet formation liquid-phase microextraction (SFDF-LPME). Copper ion was complexed with a Schiff base chelating agent called as N,N′-Bis(salicylidene)-1,2-phenylenediamine (BSP). Under the optimum conditions, the developed SFDF-LPME-FAAS and FAAS system were assessed with respect to limit of detection (LOD), limit of quantitation (LOQ), linearity and percent relative standard deviation (%RSD). LOD and LOQ values for SFDF-LPME-FAAS method were found to be 6.0 and 19.9 µg/kg, respectively. Enhancement in calibration sensitivity for developed method was found as 23 folds. In addition, accuracy/suitability of the developed SFDF-LPME-FAAS method were confirmed by spiking experiments. Two different apple tea samples were spiked to different concentration values and percent recovery results from 91.1 and 123.8 % proved the accuracy/suitability of the method.