In the current study, a new technique was developed for quantification and qualification of pseudoephedrine hydrochloride (PSE) in a real sample, which was based on electrochemical sensors and molecular imprinted polymer (MIP). The carbon paste electrode (CPE) was modified and optimized by a different ratio of MIP. MIP/CPE was used as the extraction and working electrode. Differential pulse voltammetry (DPV) method was utilized for measurement. The MIP (molecularly imprinted polymer) and NIP (non-imprinted polymer) were synthesized by various ratios of functional monomer (methacrylic acid) and cross-linker (ethylene glycol dimethacrylate) and template (pseudoephedrine hydrochloride). Some parameters such as pH, extraction time, MIP/CP ratio, stirring rate, and concentration of sample were optimized, and under these conditions, the oxidation peak current was proportional to the pseudoephedrine hydrochloride concentration over a range of 10-500 µM with the coefficient of determination 0.992 (R2). The limit of detection (LOD) was found about 0.274 µM and the limit of quantification (LOQ) was located about 0.825 µM. The relative standard deviation (RSD) was about 1.17%. The results indicated that the modified electrode had a specific ability in selective extraction of pseudoephedrine hydrochloride. Manuscript profile

در این پژوهش، جاذب جدیدی با پوششدادن نانوذره مغناطیسی آهن با تترااتیل‌اورتوسیلیکات، سدیم دودسیل‌سولفات و دی‌متیل‌گلی‌اکسی (Fe3O4@SiO2@SDS/DMG) به‌عنوان یک روش ساده، ارزان، سریع، برای بازیابی، پیش‌تغلیظ و اندازه‌گیری مقادیر ناچیز پالادیم در نمونه‌های آبی تهیه شد. در این روش پیشنهادی، یون بازداری شده بر سطح فاز جامد، با محلول تیواوره - هیدروکلریک اسید شسته و غلظت آن با طیف‌سنجی جذب اتمی شعله اندازه‌گیری شد. عامل‌های مؤثر بر فرایند استخراج مانند pH محلول، زمان استخراج، نوع و حجم شوینده، مقدار فاز جاذب بر درصد بازیابی یون پالادیم با استفاده از روش ناپیوسته بررسی شد. تحت شرایط بهینه، عامل تغلیظ، حدتشخیص، گستره خطی و انحراف استاندارد نسبی به ترتیب 250، μgl-1 0/49، 125 تا μgl-1 3750 و 26/2 % به‌دست آمد. درنهایت این روش با موفقیت برای بازیابی و اندازه‌گیری مقادیر ناچیز پالادیم در نمونه‌های آبی متفاوت به‌کار گرفته شد. این روش ساده، سریع، با حساسیت و گزینش‌پذیری خوب است. Manuscript profile

در این پژوهش، یک روش ساده و مؤثر برای پیش‌تغلیظ و اندازه‌گیری یون پالادیم براساس جابه‌جایی با کمپلکس Cu(DDTC)2 در نمونه‌های آبی ارائه‌شده است. این روش شامل دو مرحله است. برای به حداقل رساندن مزاحمت‌های یونی ابتدا +Cu2 با دی‌اتیل‌دی‌تیوکاربامات، برای تشکیل کمپلکس Cu(DDTC)2 واکنش داده که با روش میکرو استخراج مایع-مایع پخشی با کمک میکروقیف و با استفاده از نرمال اکتانول (به‌عنوان حلال استخراج‌کننده) استخراج شد. در ادامه، برای تشکیل کمپلکس +Pd(DDTC)2، Pd2 جایگزین +Cu2 در فاز آلی شده و سپس، غلظت آن با طیف‌سنجی جذب اتمی شعله اندازهگیری شد. عامل‌های مؤثر بر بازدهی استخراج با استفاده از روش باکس-بنکن بررسی و بهینه شدند. تحت شرایط بهینه، عامل تغلیظ، حد تشخیص و انحراف استاندارد نسبی (8 = n) به ترتیب برابر با 153، μgl-1 22/1 و 9/4 % به‌دست آمد. درنهایت، این روش به‌خوبی توانست مقادیر ناچیز پالادیم را در نمونه‌های آبی اندازه‌گیری کند. Manuscript profile

An efficient, rapid, simple, and highly selective dispersive liquid–liquid microextraction basedon solidification of floating organic drop (DLLME-SFOD), combined with flame atomicabsorption spectrometry was developed for preconcentration and determination of trace amountsof cobalt in water samples. In this method, an appropriate mixture of acetone and1-undecanol was injected rapidly into the aqueous sample containing cobalt-2N1N complex, as aresult cloudy mixture was formed. After centrifugation, the test tube was cooled for 5 min. Thesolidified 1-undecanol on top of the solution was transferred into a suitable vial. Then, it wasdissolved in 100 μL of methanol and finally introduced into the flame atomic absorption bymicrosampler injector. Several factors influencing the microextraction efficiency, such as thenature and volume of organic solvent, pH of aqueous solution, amount of complexing agent,stirring rate and extraction time were investigated and optimized. Under the optimum conditions,the enhancement factor was 68. The limit of detection, 6 μgL−1 and relative standard deviation(RSD) 2.64% (n=8) were obtained. The proposed method was applied to the analysis of variouswater samples. Manuscript profile

A simple, rapid and efficient dispersive liquid–liquid microextraction by use of ionic liquid (IL-DLLME)method, followed by flame atomic absorption spectrometry (FAAS) was developed for the preconcentrationand determination of palladium in water samples. In this method, an appropriate mixture of acetone and octylmethyl imidazolium hexafluorophosphate was injected rapidly into the aqueous sample containingpalladium-DDTC complex, as a result cloudy mixture was formed. After extraction of palladium complexinto fine droplet, the mixture was centrifuged. As a result, fine organic drop was setteled in the bottom of testtube. After remove of aqueous solution and dilution of organic phase; it was introduced into the flame atomicabsorption by microsampler injector. Several parameters influencing the microextraction efficiency, such asthe nature and volume of organic solvent, pH of aqueous solution, amount of complexing agent, stirring rateand extraction time were investigated and optimized. The applicability of technique was evaluated bydetermination of trace amounts of palladium in several water samples. Under the optimum conditions, theenhancement factor was 83. The limit of detection, 2.8 μgL−1 and relative standard deviation (RSD) 4.31 %(n=10) were obtained. Manuscript profile

In this study, trace amounts of manganese ions were extracted using a sensitive, selective, rapid, and simple micro-funnel magnetic stirring-assisted liquid phase microextraction (MF-MSA-LPME) method and determined by flame atomic absorption spectrometry (FAAS). 1-(2-Thiazolylazo)-2-naphthol) (TAN) and 1-octanol were chosen as chelating agent and extraction solvent, respectively. The effective parameters on extraction efficiency such as type and volume of extraction solvent, pH of sample solution, ligand concentration, extraction time, and ion strength ‎were investigated and optimized. Under the optimum form, limit of detection (LOD), relative standard deviation, and the enrichment factor were 0.16 μg L-1, 2.9%, and 252, respectively. The calibration graph was linear over the range of 1-120 μg L-1 with correlation of coefficient r2 = 0.995.The proposed method could successfully determine trace amounts of manganese ions ‎in the real water samples with good accuracy and validity. Manuscript profile

A rapid, simple, precise, accurate, and environmentally friendly spectrophotometric method was developed and validated for simultaneous determination of Sacubitril and Valsartan in their combined dosage form, using continuous wavelet transform (CWT) and zero-crossing techniques without using organic solvents and the time-consuming extraction step.Initially, UV spectra of two pure components in water were processed via various mother wavelet families. Then, applying zero-crossing technique, the optimum points were found to obtain appropriate calibration curves for each point. The calibration curves were linear for both Sacubitril and Valsartan. The validation of these methods was investigated by analyzing several synthetic mixtures with known concentrations. Applying one-way analysis of variance (ANOVA) test and Fisher pairwise comparisons, the following were found to yield the best results: Discrete Meyer (dmey) wavelet functions with scaling factor of 61 at 232 nm and Symlet5 (sym5) with 48 at 232 nm for Sacubitril and Meyer (meyr) with 50 at 272 nm, meyr with 59 at 247 nm, Daubechies (db5) with 53 at 237 nm, and sym5 with 59 at 226 nm for Valsartan. The mean recovery values in synthetic mixtures were between 99.09% and 101.16% using the proposed methods, where relative standard deviation (RSD) not more than 1.23% proved to have good precision. The obtained results from the commercial tablets, applying the developed methods, were compared to those yielded by HPLC method by one-way ANOVA test.According to the results, they were in good agreement and showed no significant differences, thereby suggesting successful determination in accordance with green chemistry. Manuscript profile