scholarly journals Studying the quenching resulted from the formation of an association complex between olsalazine or sulfasalazine with acriflavine

2021 ◽  
Vol 8 (4) ◽  
Author(s):  
Manar Tolba ◽  
Heba Elmansi
Keyword(s):  
Ulcerative Colitis ◽  
Correlation Coefficients ◽  
Safe Method ◽  
Quenching Effect ◽  
Spectrofluorimetric Method ◽  
Spectrofluorometric Method ◽  
Optimized Conditions ◽  
Green Criteria ◽  
Association Complex ◽  
Detection And Quantification

We report the detection and quantification of important ulcerative colitis drugs olsalazine (OLS) and sulfasalazine (SUL) by the spectrofluorometric method. The proposed method was optimized and validated by using the quenching effect on the acriflavine fluorescence. The method was applied on the detection and quantification of OLS and SUL under optimized conditions showing the calibration curves were linear (range: 1.0–10.0 µg ml −1 ), with correlation coefficients R 2 of 0.9999 for both drugs. The limits of detection (LOD) and quantification (LOQ) were 53 and 104 ng ml −1 for the OLS and 160 and 315 ng ml −1 for the SUL. This method permitted the analysis of OLS and SUL in their pure and pharmaceutical forms. The proposed spectrofluorimetric method was also evaluated against ‘green’ criteria and all the experimental results make it an eco-friendly and safe method for the detection of OLS and SUL.

A Profoundly Touchy Approved Spectrofluorimetric Approach for Assurance of Ixabepilone as Anticancer Drug by Utilizing Its Quenching Impact on Acetoxymercuric Fluorescein Reagent

2021 ◽  
pp. 39-52
Author(s):  
Hesham Salem ◽  
Amany Abdelaziz ◽  
Aliaa Gamal ◽  
Ramy El Sabaa
Keyword(s):  
Human Plasma ◽  
Anticancer Drug ◽  
Fluorescence Intensity ◽  
Solution Concentration ◽  
Quenching Effect ◽  
Bulk Powder ◽  
Optimized Conditions ◽  
Temperature Time ◽  
Sulfur Containing ◽  
Satisfactory Recovery

A dependable, sensitive, basic and cheap spectrofluorimetric approach has been created for test of sulfur-containing drug; ixabepilone in bulk powder, vials and human plasma. The approach depends on the quenching effect of ixabepilone on the fluorescence intensity of acetoxymercuric fluorescene (AMF) reagent at λem of 530 nm and λex of 500 nm. Parameters which will control the reaction such as pH, AMF solution concentration, temperature, time and solvents were examined and optimized. According to the optimized conditions, the proposed approach was practiced over the concentration area of 20-100 ng mL-1 with adequate linearity (r = 0.9998). The developed approach was approved confirming to ICH rules in terms of accuracy, precision, linearity, LOD and LOQ. The proposed approach was practiced to analyze ixabepilone in Ixempra® vials with satisfactory recovery % of 99.89 and RSE% of 1.24. The results achieved were compared to those achieved by an already reported HPLC approach.

scholarly journals Facile Detection and Quantification of Acetamiprid Using a Portable Raman Spectrometer Combined with Self-Assembled Gold Nanoparticle Array

Chemosensors ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 327
Author(s):  
Panxue Wang ◽  
Yan Sun ◽  
Li Wang ◽  
Xiang Li ◽  
Miaomiao Liu ◽  
...  
Keyword(s):  
Gold Nanoparticle ◽  
Correlation Coefficients ◽  
Nanoparticle Array ◽  
Sers Signal ◽  
Sers Substrates ◽  
Specificity And Sensitivity ◽  
Exciting Opportunity ◽  
Sers Detection ◽  
Self Assembled ◽  
Detection And Quantification

Rapid and facile determination of pesticides is critically important in food and environmental monitoring. This study developed a self-assembled gold nanoparticle array based SERS method for highly specific and sensitive detection of acetamiprid, a neonicotinoid pesticide that used to be difficult in SERS analysis due to its low affinity with SERS substrates. SERS detection and quantification of acetamiprid was conducted with self-assembled gold nanoparticle arrays at the interface of chloroform and water as the enhancing substrate. Since targets dissolved in chloroform (organic phase) also have access to the hot-spots of Au NP array, the developed method exhibited good sensitivity and specificity for acetamiprid determination. Under the optimal conditions, SERS intensities at Raman shifts of 631 cm−1 and 1109 cm−1 displayed a good linear relationship with the logarithm concentration of acetamiprid in the range of 5.0 × 10−7 to 1.0 × 10−4 mol/L (0.11335 ppm to 22.67 ppm), with correlation coefficients of 0.97972 and 0.97552, respectively. The calculated LOD and LOQ of this method were 1.19 × 10−7 mol/L (0.265 ppb) and 2.63 × 10−7 mol/L (0.586 ppb), respectively, using SERS signal at 631 cm−1, and 2.95 × 10−7 mol/L (0.657 ppb) and 3.86 × 10−7 mol/L (0.860 ppb) using SERS signal at 1109 cm−1, respectively. Furthermore, the developed SERS method was successfully applied in determining acetamiprid on the surface of apple and spinach. This method offers an exciting opportunity for rapid detection of acetamiprid and other organic pesticides considering its advantages of simple preparation process, good specificity and sensitivity, and short detection time (within 1 h).

scholarly journals Ionic Liquid-modified NiTi Composite Nanosheets Coating for Efficient Solid Phase Microextraction of Octadecylamine in Brine

2019 ◽  
pp. 1-8
Author(s):  
Huiju Wang
Keyword(s):  
Ionic Liquid ◽  
Solid Phase Microextraction ◽  
Extraction Efficiency ◽  
Solid Phase ◽  
Correlation Coefficients ◽  
Fiber Coating ◽  
Relative Standard ◽  
Optimized Conditions ◽  
As Solid Phase

Ionic     liquid (IL), 1-dodecyl-3-methylimidazolium-3-hydroxy-2-naphthoate (C12mimHNC) was synthesized and coated on the surface of NiTi as solid phase microextractiom fiber coating for determination the octadecylamine in brine. Prior to modification with IL, the NiTi was hydrothermally treated for in-situ growth of titanium and nickel oxide composite nanosheets (TiO2/NiOCNSs). The TiO2/NiOCNSs fibers coating was oriented  around the NiTi  substrate and  presented  double-faced  open  access  sites,  which provided a desired support framework for the further modification with IL. The extraction performance of C12mimHNC-TiO2/NiOCNSs fiber coating was evaluated for       detection of octadecylamine (ODA) coupled to HPLC with UV detection. As a result, the C12mimHNC-TiO2/NiOCNSs fiber coating illustrated excellent adsorption and extraction capability for ODA. The main factors affected extraction efficiency were optimized. Under the optimized  conditions,  good  linearity was  obtained  in  the  range of  1-150  µg/L with correlation  coefficients  (r2)  above  0.985.  Limits of detection (LODs) for  the  developed method was 0.280 µg/L. The proposed method was first applied to extract the ODA in brine samples. Relative recoveries varied from 78.3% to 96.5% at spiking level of 15µg/L and 30 µg/L with the relative standard deviations (RSDs) less than 8.7%.

scholarly journals New Spectrofluorimetric Method with Enhanced Sensitivity for Determination of Paroxetine in Dosage Forms and Plasma

2008 ◽  
Vol 3 ◽  
pp. ACI.S1053 ◽  
Author(s):  
Ibrahim A. Darwish ◽  
Sawsan M. Amer ◽  
Heba H. Abdine ◽  
Lama I. Al-Rayes
Keyword(s):  
High Sensitivity ◽  
Dosage Forms ◽  
Official Method ◽  
Factors Affecting ◽  
Pharmaceutical Tablets ◽  
Enhanced Sensitivity ◽  
Spectrofluorimetric Method ◽  
Relative Standard ◽  
Optimized Conditions

New simple spectrofluorimetric method with enhanced sensitivity has been developed and validated for the determination of the antidepressant paroxetine (PXT) in its dosage forms and plasma. The method was based on nucleophilic substitution reaction of PXT with 4-chloro-7-nitrobenzo-2-oxa-1,3-diazole in an alkaline medium (pH 8) to form a highly fluorescent derivative that was measured at 545 nm after excitation at 490 nm. The factors affecting the reaction was carefully studied and optimized. The kinetics of the reaction was investigated, and the reaction mechanism was presented. Under the optimized conditions, linear relationship with good correlation coefficient (0.9993) was found between the fluorescence intensity and PXT concentration in the range of 80-800 ng ml-1. The limits of detection and quantitation for the method were 25 and 77 ng ml-1, respectively. The precision of the method was satisfactory; the values of relative standard deviations did not exceed 3%. The proposed method was successfully applied to the determination of PXT in its pharmaceutical tablets with good accuracy; the recovery values were 100.2 ± 1.61%. The results obtained by the proposed method were comparable with those obtained by the official method. The proposed method is superior to the previously reported spectrofluorimetric method for determination of PXT in terms of its higher sensitivity and wider linear range. The high sensitivity of the method allowed its successful application to the analysis of PXT in spiked human plasma. The proposed method is practical and valuable for its routine application in quality control and clinical laboratories for analysis of PXT.

scholarly journals Development and validation of a new spectrofluorimetric method for the determination of some beta-blockers through fluorescence quenching of eosin Y. Application to content uniformity test

2016 ◽  
Vol 14 (1) ◽  
pp. 258-266 ◽  
Author(s):  
Sayed M Derayea ◽  
Mahmoud A Omar ◽  
Mohamed Aboel-Kasem Abdel-Lateef ◽  
Ahmed I. Hassan
Keyword(s):  
Fluorescence Quenching ◽  
Beta Blockers ◽  
Dosage Forms ◽  
Ion Pair ◽  
Content Uniformity ◽  
Eosin Y ◽  
Pharmaceutical Dosage Forms ◽  
Quenching Effect ◽  
Spectrofluorimetric Method

AbstractA simple, rapid, sensitive and economic spectrofluorimetric method has been developed and validated for determination of some β-adrenergic blocking agents namely; betaxolol hydrochloride (BTX), carvedilol (CAR), labetalol hydrochloride (LBT), nebivolol hydrochloride (NEB) and propranolol hydrochloride (PRO). The method is based on the quenching effect of the cited drugs on the fluorescence intensity of eosin Y at pH 3.4 (acetate buffer). The fluorescence quenching is due to the formation of an ion-pair complex and was measured without extraction at 545 nm (λex. 301.5 nm). The factors affecting the formation of the ion-pair complex were carefully studied and optimized. Under the optimal conditions, the linear ranges for the relationship between the fluorescence quenching value and the concentration of the investigated drugs were 100-2500, 150-2500 and 50-2250 ng mL-1 for (BTX, CAR), (LBT, NEB) and (PRO) respectively. The method was validated according to ICH guidelines and was applied for determination of the cited drugs in pharmaceutical dosage forms with excellent recoveries. In addition, content uniformity testing of some commercial dosage forms was checked by the proposed method.

Detection and quantification of cytomegalovirus in ulcerative colitis using a fecal PCR-assay: Important therapeutic consequences in refractory disease

2001 ◽  
Vol 120 (5) ◽  
pp. A270
Author(s):  
Daniel W. Hommes ◽  
Jan F.L. Weel ◽  
Joep F.W. Bartelsman ◽  
Marieke Tom ◽  
W.R. Boom ◽  
...  
Keyword(s):  
Ulcerative Colitis ◽  
Refractory Disease ◽  
Pcr Assay ◽  
Therapeutic Consequences ◽  
Detection And Quantification

scholarly journals Development of a Traditional Chinese Medicine Syndrome-Specific Scale for Ulcerative Colitis: The Large Intestine Dampness-Heat Syndrome Questionnaire

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Xin-lin Chen ◽  
Yi Wen ◽  
Zu-chun Wu ◽  
Bei-ping Zhang ◽  
Zheng-kun Hou ◽  
...  
Keyword(s):  
Ulcerative Colitis ◽  
Large Intestine ◽  
Characteristic Curve ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Diagnostic Efficacy ◽  
Construct Definition ◽  
Traditional Chinese Medicine Syndrome ◽  
Intraclass Correlation Coefficients ◽  
Heat Syndrome

The aim of this study was to develop and validate the large intestine dampness-heat syndrome questionnaire (LIDHSQ) for patients with ulcerative colitis (UC). The domains and items of the LIDHSQ were developed according to standard procedures, namely, construct definition, item generation, language testing, content validity, pilot study, and validation study. At first, a total of 20 items in 3 domains were generated based on literature review and expert consultation. After the item selection, the LIDHSQ contains 11 items in three domains: disease-related domain (diarrhoea, abdominal pain, bloody purulent stool, and mucus stool), heat domain (fever, dry mouth, red tongue, yellow fur, and anal burning), and dampness domain (greasy fur and defecation disorder). The Cronbach's alphas of all domains were greater than 0.6. All of the intraclass correlation coefficients were greater than 0.8. The LIDHSQ and domain scores of the patients with LIDHS were higher than those of the patients with other syndromes (P < 0.001). The area under the receiver operating characteristic curve of the LIDHSQ was 0.900, with a 95% confidence interval of 0.872–0.928. When the cut-off value of the LIDHSQ was ≥ 7, the sensitivity and specificity were 0.867 and 0.854, respectively. The LIDHSQ is valid and reliable for measuring LIDHS in UC patients with good diagnostic efficacy. We recommend the use of the LIDHSQ in Chinese UC patients.

scholarly journals A Novel Application of Natural Peat for Solid-Phase Extraction of Pyrimethanil, Flumetralin, and Kresoxim-Methyl in Water Using Gas Chromatography-Mass Spectrometry

2012 ◽  
Vol 2012 ◽  
pp. 1-5
Author(s):  
Alex S. M. S. J. Santos ◽  
Adriano Aquino ◽  
Luciane P. C. Romão ◽  
Sandro Navickiene
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Solid Phase Extraction ◽  
Solid Phase ◽  
Correlation Coefficients ◽  
Gas Chromatography Mass Spectrometry ◽  
Phase Extraction ◽  
Selected Ion Monitoring ◽  
Chromatography Mass Spectrometry ◽  
Detection And Quantification

Natural peat was tested for extraction of pyrimethanil, flumetralin, and krexosim-methyl from water, with analysis using gas chromatography-mass spectrometry (GC-MS) in selected ion monitoring mode (SIM). Experiments were carried out at one fortification level (0.1 μg L−1) and resulted in recoveries in the range 41–96%, with RSD values between 6.8 and 12.6% for natural peat as sorbent. Detection and quantification limits ranged from 0.02 to 0.05 μg L−1 and from 0.07 to 0.1 μg L−1, respectively, for the different pesticides studied. The method developed was linear over the range tested (0.07–4.0 μg L−1), with correlation coefficients ranging from 0.9919 to 0.9989. Comparison between peat and commercial sorbents (C18-bonded silica, ENVI-Carb, Florisil, silica gel, ENVI-Carb/LC-NH2) showed better performance of peat sorbent for flumetralin and kresoxim-methyl.

Multiparameter Optimization of Magnetite Solid-phase Microextraction for Preconcentration of Diclofenac and Determination by UV-Vis Spectrophotometry

2021 ◽  
Author(s):  
Hassan Ali Shahhosseini ◽  
Somayeh Heydari ◽  
Zarrin Es'haghi ◽  
Leili Zare
Keyword(s):  
Solid Phase ◽  
Correlation Coefficients ◽  
Sample Volume ◽  
Effective Parameters ◽  
Dialdehyde Starch ◽  
Main Effect ◽  
Ft Ir ◽  
Multiparameter Optimization ◽  
Optimized Conditions

Abstract This research, aimed to synthesis and functionalize of Fe3O4 magnetic nanoparticles (MNPs) using dialdehyde starch and modifying with arginine amino acid. The resulting MNPs were characterized by Fourier transform infrared spectroscopy (FT-IR), Scanning electron microscope (SEM) and Vibrating sample magnetometer (VSM). Synthesized MNPs were developed for preconcentration and determination of diclofenac in biological samples by UV- Vis Spectrophotometry. A Plackett–Burman experimental design was used to evaluate the influence of effective parameters. Significant parameters were further optimized by Central Composite Design (CCD). Sample volume, pH and salting effect had a main effect on extraction of diclofenac by the proposed method. Under the optimized conditions, the detection limit (3Sb, n = 7) was found to be 0.039 µg ml− 1.The calibration curve showed dynamic linear 0.05-10 µg ml− 1 with correlation coefficients (R2) of 0.987. The enrichment factor was found to be 148. The proposed method showed good results for preconcentration and determination of diclofenac in serum and pharmaceutical samples.

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