Calcium/Copper alginate framework doped with CuO nano-particles as a novel adsorbent for micro-extraction of benzodiazepines from human serum

2020 ◽  
Vol 16 ◽  
Author(s):  
Nadereh Rahbar ◽  
Fatemeh Ahmadi ◽  
Zahra Ramezani ◽  
Masoumeh Nourani

Background: Sample preparation is one of the most challenging phases in pharmaceutical analysis, especially in biological matrices, affecting the whole analytical methodology. Objective: In this study, a new Ca(II)/Cu(II)/alginate/CuO nanoparticles hydrogel fiber (CCACHF) was synthesized through a simple, green procedure and applied for fiber micro solid phase extraction (FMSPE) of diazepam (DIZ) and oxazepam (OXZ) as model drugs prior to high-performance liquid chromatography-UV detection (HPLC-UV). Methods: Composition and morphology of the prepared fiber were characterized and the effect of main parameters on the fiber fabrication and extraction efficiency have been studied and optimized. Results: In optimal conditions, calibration curves were linear ranging between 0.1–500 µg L−1 with regression coefficients of 0.9938 and 0.9968. Limit of detection (LOD) (S/N=3) and limit of quantification (LOQ) (S/N=10) of the technique for DIZ and OXZ were 0.03 to 0.1 µg L−1. Within-day and between-day relative standard deviations (RSDs) for DIZ and OXZ were 6.0–12.5% and 3.3–9.4%, respectively. Conclusion: The fabricated adsorbent has been substantially employed to extraction of selected benzo-diazepines (BZDs) from human serum real specimens and the obtained recoveries were also satisfactory (82.1-109.7%).

2013 ◽  
Vol 469 ◽  
pp. 444-449
Author(s):  
Yu Zi Liu ◽  
Ying Hao Xing ◽  
Jun Wu

In this study, High Performance Liquid Chromatography (HPLC), combined with Triple Quadruple mass Spectrometry (QQQ) were developed and applied in the analysis of 16 phthalic acid esters (PAEs) in the common drinking water. Qualitative and quantitative analysis were carried out by Multiple Reaction Monitoring (MRM). The method, combined with Solid Phase Extraction, was established to detect the PAEs in drinking water. As showed by the results, 16 PAEs had a good linearity in the range of 1.14~101.4μg/L, with correlation coefficient between 0.996~0.999. The mean recoveries were in the range of 87.53~131.37%, with the relative standard deviation be 0.71~5.09%. The limit of quantification (LOQ) of 16 PAEs were between 1.14~32.51μg/L, with the limit of detection (LOD) be 0.34~10.67μg/L. There were five PAEs which were detected in the range of <1.7~17.2μg/L in bottled water. Some products have some PAEs which havent been shown in the national or the international standard of the drinking water.


2021 ◽  
Vol 21 (5) ◽  
pp. 1196
Author(s):  
Ungku Amirul Arif Ungku Abdullah ◽  
Nor Suhaila Mohamad Hanapi ◽  
Wan Nazihah Wan Ibrahim ◽  
Nursyamsyila Mat Hadzir ◽  
Nurzaimah Zaini ◽  
...  

Existing methods used in tracing Tetracyclines' antibiotics (TCAs) residues which pose serious environmental problems, consume high amounts of organic solvents, are time-consuming, and are relatively expensive. A simple and effective magnetic solid-phase extraction (MSPE) based on reduced graphene oxide/magnetite (RGO/Fe3O4) nanocomposite sorbent was successfully developed for preconcentration and extraction of TCAs residues from water samples. The analytes were determined by high-performance liquid chromatography with a diode-array detector (HPLC-DAD). The synthesized nanocomposite was characterized using Fourier-transform infrared spectroscopy (FTIR), X-ray diffractometry (XRD), and field emission scanning electron microscopy (FESEM). Sample pH, amount of adsorbent, sample volume, extraction time, desorption time, and desorption solvent were evaluated and optimized. Under optimized conditions, the method demonstrated good linearity over the concentration range of 0.05–1.0 mg L–1 with the coefficient of determination (R2) ≥ 0.9978. Limit of detection (LOD) and limit of quantification (LOQ) were 0.006–0.011 mg L–1 and 0.019–0.036 mg L–1, respectively. The accuracy and precision of the developed method were proven by good analyte recovery (89.77–106.33%) and acceptable precision with relative standard deviation, RSD ≤ 5.54%. The results showed that magnetic solid RGO/Fe3O4 could be a suitable adsorbent in the preconcentration and extraction of TCAs in water samples.


Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 1837
Author(s):  
Harischandra Naik Rathod ◽  
Bheemanna Mallappa ◽  
Pallavi Malenahalli Sidramappa ◽  
Chandra Sekhara Reddy Vennapusa ◽  
Pavankumar Kamin ◽  
...  

A quick, sensitive, and reproducible analytical method for the determination of 77 multiclass pesticides and their metabolites in Capsicum and tomato by gas and liquid chromatography tandem mass spectrometry was standardized and validated. The limit of detection of 0.19 to 10.91 and limit of quantification of 0.63 to 36.34 µg·kg−1 for Capsicum and 0.10 to 9.55 µg·kg−1 (LOD) and 0.35 to 33.43 µg·kg−1 (LOQ) for tomato. The method involves extraction of sample with acetonitrile, purification by dispersive solid phase extraction using primary secondary amine and graphitized carbon black. The recoveries of all pesticides were in the range of 75 to 110% with a relative standard deviation of less than 20%. Similarly, the method precision was evaluated interms of repeatability (RSDr) and reproducibility (RSDwR) by spiking of mixed pesticides standards at 100 µg·kg−1 recorded anRSD of less than 20%. The matrix effect was acceptable and no significant variation was observed in both the matrices except for few pesticides. The estimated measurement uncertainty found acceptable for all the pesticides. This method found suitable for analysis of vegetable samples drawn from market and farm gates.


2003 ◽  
Vol 68 (8-9) ◽  
pp. 691-698 ◽  
Author(s):  
Milena Jelikic-Stankov ◽  
Predrag Djurdjevic ◽  
Dejan Stankov

In this work a new enzymatic method for the determination of uric acid in human serum has been developed. The method is based on the oxidative coupling reaction between the N-methyl-N-(4-aminophenyl)-3-methoxyaniline (NCP) reagent and the hydrogen ? donor reagent N-ethyl-N-(2-hydroxy-3-sulfopropyl)-3-methylaniline (TOOS), in the system involving three enzymes: uricase, peroxidase and ascorbate oxidase. Using this method uric acid could be determined in concentrations up to 1.428 mmol/L, with a relative standard deviation of up to 1.8 %. The effect of the medium pH and the NCP concentration on the linearity of the chromogen absorbance versus the uric acid concentration curve was investigated. The influence of the uricase activity on the maximum rate of uric acid oxidation was also examined. The use of the NCP reagent demonstrated a more precise and more sensitive determination of the uric acid compared to the determination with 4-aminoantipyrine (4-AA) as the coupling regent. The sensitivity of the method determined from the calibration curve was 0.71 absorbance units per mmol/L of uric acid; the limit of detection was LOD = 0.0035 mmol/L and the limit of quantification was LOQ = 0.015 mmol/L of uric acid.


INDIAN DRUGS ◽  
2021 ◽  
Vol 58 (07) ◽  
pp. 59-65
Author(s):  
Vinita C. Patole ◽  
Shilpa P. Chaudhari ◽  

An attempt was made to develop a simple, selective, rapid and precise high-performance liquid chromatography (HPLC) method for simultaneous estimation of thymol and eugenol. Analysis was performed on a C18 column with the mobile phase consisting of solvent %A (water) and solvent %B (acetonitrile) with the following gradient: 0–1 min, 80 % A, 20 % B; 1–7 min, 40 % A and 60 % B; 7–12 min, 10 % A and 90 % B; and 12–15min, 80 % A and 20 % B at a flow rate of 0.6 mL/min. The compounds were well separated on a Thermo Scientific Hypersil BDS RP C18 column (4.6 mm × 150 mm, dp = 5 µm) and ultraviolet detection at 280 nm. The retention times of eugenol and thymol were 10.5 min and 11.6 min, respectively. Validation of the proposed method was carried out according to the guidelines of the International Council on Harmonization (ICH). The linearity of the method is good for thymol and eugenol over the concentration range of 1–50 ppm, and the r 2 values were 0.9996 for both thymol and eugenol. The calculated limit of detection (LOD) value was 0.5ppm and the limit of quantification (LOQ) value was 1ppm for both the analytes. The intra and interday relative standard deviation (RSD) of the retention time and peak areas was less than 3 %.The established method was appropriate, and the two markers were well resolved, enabling efficient quantitative analysis of thymol and eugenol.


2021 ◽  
Vol 09 ◽  
Author(s):  
Ali Al-Kulabi ◽  
Louis Gooden ◽  
Ijeoma F. Uchegbu

Background: Mycophenolic acid (MPA), an immunosuppressive agent, is used orally to reduce corneal graft rejection. However its oral use is associated with gastrointestinal side effects. Objectives: To prepare MPA nanoparticle eye drops and a validated analytical method. Methods: Aqueous MPA eye drops were prepared by nanoencapsulation of MPA using Nanomerics MET (N-palamitoylN-monomethyl-N,N-dimethyl-N,N,N-trimethyl-6-O-glycolchitosan) at a MET, MPA ratio of 7.5: 1 g g-1 in the presence of glycerol (2.75% w/w). A validated MPA in-formulation drug substance assay was then developed. Results: MET-MPA formulations were prepared as well as a validated assay. Assay validation parameters for the analysis of MPA in the formulation were satisfactory [Plate count = 16458, Capacity Factor = 2.4, Tailing Factor = 1.02, linearity = 0.999 (0.016 – 0.5 mg mL-1 ), limit of detection = 0.056 mg mL-1 , limit of quantification = 0.17 mg mL-1 , accuracy = 98%, intraday and interday relative standard deviation = 0.45% and 4% respectively]. The candidate formulation (z - average mean = 66 ± 0.4 nm, polydispersity index = 0.12 ± 0.012, drug content = 1.14 ± 0.003 mg mL-1 , zeta potential = +8.5 ± 1.4 mV, pH = 7.4 ± 0.02, osmolarity = 309 ± 1.5 mOSm L-1 , viscosity = 1.04 ± 0.001 mPa.s) was then found to be stable for 14 days with respect to drug content at refrigeration, room and accelerated (40C )temperature and. All other formulation parameters were within the ocular comfort range. Conclusions: A validated assay (ICH and US FDA guidelines) for new MPA nanoparticle eye drops has been developed.


2019 ◽  
Vol 8 (1) ◽  
pp. 17-21
Author(s):  
Lanlan Wei ◽  
Jianjun Deng ◽  
Tao Kang ◽  
Xuejun Kang

A method for the determination of Rhodamine B in sausage was developed and validated. After extraction of Rhodamine B with acetonitrile from foodstuffs, a novel electrospun polymer nanofibers packed micro-column was used for cleaning and concentrating of the analyte in the sample. High performance liquid chromatography with fluorescence detection (HPLC-Flu) was used for the determination of Rhodamine B in the sample. The mobile phase was composed of 3.0 g L-1 phosphate buffer and methanol (3:7, volume ratio), and the pH was adjusted to 7. 0 with orthophosphoric acid. The results showed that the standard curve was linear over the validated concentrations range of 2-500 ng g-1, and the limit of detection (LOD) and the limit of quantitation (LOQ) for Rhodamine B spiked samples was 0. 2 ng g-1 and 0. 7 ng g-1, respectively. The average recoveries of Rhodamine B were 90.4% -94.3% for sausage, and the relative standard deviation of the method was from 1.7% to 3.8%. This proposed method was applied to real sample, and there was no Rhodamine B found in sausage.


2016 ◽  
Vol 35 (2) ◽  
pp. 225 ◽  
Author(s):  
Violeta Ivanova-Petropulos ◽  
Krste Tašev ◽  
Marina Stefova

<p>A solid-phase extraction method followed by reverse phase high-performance liquid chromatography (RP-HPLC) was optimized and validated for the quantitative determination of tartaric, malic, shikimic, lactic, citric and succinic acids in wine. Solid-phase extraction was carried out with C18 cartridges and extraction recoveries for all acids ranging from 98.3 to 103% were obtained. HPLC separation was performed with isocratic elution on a LiChrosorb RP-18 column (250 × 4.6 mm I.D., 5 µm) protected with the appropriate guard column. The mobile phase was a 5 mM solution of H<sub>3</sub>PO<sub>4</sub> with pH 2.1 at a flow rate of 1 ml/min. Detection of the organic acids was performed at 210 nm. The developed method was validated by checking its linearity, limit of detection (LOD), limit of quantification (LOQ), precision and recovery. The method was applied to the analysis of organic acids in Macedonian red and white wines.</p>


2007 ◽  
Vol 90 (2) ◽  
pp. 568-574 ◽  
Author(s):  
Chen Xuyan ◽  
Hu Jiye ◽  
Li Jianzhong

Abstract A method has been developed for the quantitation of imazaquin residues in soil. The herbicide was extracted from soil with methanolwater (2 + 1, v/v) and cleaned up by strong anion-exchange solid-phase extraction cartridges. Analysis was performed by using high-performance liquid chromatography with ultraviolet detection. Average recoveries through the method ranged from 90.7 to 100.6%, with relative standard deviation equal to or lower than 6.6%. The limit of detection was estimated to be 0.0015 mg/kg, and the minimum quantitation concentration of imazaquin in soil was 0.005 mg/kg. This method was successfully applied to evaluate imazaquin residue levels in soil and its dissipation rates in a soybean field in the Xisanqi District of Beijing, People's Republic of China. The dissipation study showed that the half life of imazaquin in soil was 10.37 0.0135 days at 3 different application rates.


Author(s):  
M. VIJAYA KUMARI ◽  
CH. BALASEKHAR REDDY

Objective: An accurate, rapid economical and straight forward, reliable assay technique was evolved and showed for the evaluation of zanubrutinib using reversed-phase high-performance liquid chromatography. Methods: In the proposed method, efficient chromatographic separation was achieved applying acetonitrile and 0.1% orthophosphoric acid (50:50 v/v) as a mobile phase with a flow of 1 ml/min and the wavelength was observed at 220 nm. Chromatography was administered isocratically at ambient temperature and run time was approximately 6 min and the retention time (Rt) was observed as 4.358 min. Results: The method was justified as per ICH guidelines. System suitability parameters were studied by injecting the quality six fold and results were well under acceptance criteria. Linearity study was administered between 10% and 150% levels, regression coefficient value was observed as 0.999. Limit of detection and limit of quantification were observed as 0.02 μg/ml and 0.2 μg/ml, respectively. Precision was found to be 0.74 for repeatability and 0.68 for intermediate precision. Recovery of the drug was found to be 98–102%, indicates that the recovery is in the acceptable limit. Validation results were found to be satisfactory and the method applicable for bulk and formulation analysis. Hence, it was evident that the proposed method was said to be suitable for regular analysis and quality control of pharmaceutical preparations. Conclusion: The validation results were in good agreement with the acceptable limit. Relative standard deviation values which are <2.0% indicating the accuracy and precision of this method. Assay of retail formulation was administered and found to be 100.24% was present using the above method. Stress conditions of degradation in acidic, alkaline, peroxide, and thermal were studied. This developed method showed reliable, precise, accurate results under optimized conditions.


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