4-Amino-Benzo[F]Isoindole-1,3-Dione Derivatives As Turn-On Fluorescent Indicators For Water Determination In Acetonitrile

2018 ◽  
pp. 183-191
Author(s):  
R. Linnik ◽  
I. Levkov ◽  
A. Chemnyi ◽  
O. Radchenko ◽  
Z. Voitenko ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Linear Response ◽  
Emission Peak ◽  
Water Determination ◽  
Fluorescent Indicators ◽  
Turn On ◽  
Peak Intensity ◽  
Relative Standard ◽  
Acetonitrile Solutions

4-Amino-9-(2,5-dioxo-pyrrolidin-1-phenyl-3-yl)-1-phenyl-benzo[f]isoindole-1,3-dione (1) and 4-amino-9-(2,5- dioxo-1-(4-methylphenyl)-pyrrolidin-3-yl)-1-(4-methylphenyl)-benzo[f]isoindole-1,3-dione (2) were studied as fluorescent indicators for water determination in acetonitrile. The intensity of fluorescence of these compounds in acetonitrile solutions increases in presence of water along with red shift of the emission peak. Intensity-based and wavelength-based procedures of water determination in acetonitrile are suggested with detection limit of 0.2 % (v/v) H2O in both cases. The linear response covers a concentration range of 0.2–20 % (v/v). The relative standard deviation at 1 % (v/v) water content is 0.20. The interferences of acetic acid, ammonia and metal ions have been studied. Ammonia and acetic acid don’t interfere with the determination of water by wavelength-based fluorescence technique. In intensity-based mode the determination of water is possible at concentration of these impurities up to 0.25 and 0.02 mol·L -1, respectively. Cu(II) ions have almost no effect on fluorescence of indicators up to 1·10 -5 mol·L -1 ; Zn (II) ions enhance fluorescence of 1 at concentration ≥ 5·10-6 mol·L-1 . The 4-amino-benzo[f]- isoindole-1,3-dione-based fluorescent indicators are pH-insensitive.

HPLC-UV Method for Determination of Famotidine from Pharmaceutical Products

2018 ◽  
Vol 69 (2) ◽  
pp. 297-299
Author(s):  
Adriana Nita ◽  
Delia Mirela Tit ◽  
Lucian Copolovici ◽  
Carmen Elena Melinte (Frunzulica) ◽  
Dana Maria Copolovici ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Quantitative Analysis ◽  
Linear Response ◽  
Mobile Phase ◽  
Acetic Acid Solution ◽  
Pharmaceutical Products ◽  
Quantification Limit ◽  
Validation Parameters ◽  
Hplc Analyses

The aim of this study was to develop and validate a rapid, accurate, and exact method for the quantitative determination of famotidine in pharmaceutical products. The HPLC analyses were performed by using a mobile phase containing methanol:1% acetic acid solution=30:7 (v/v), at a flow rate of 0.4 mL/min.The total time of the method was 10 min, and the retention time of famotidine was 4.16 min. The detection was evaluated at l=267 nm. The method has been validated by using different validation parameters. The linear response of the detector for famotidine peak area was observed at concentrations ranging from 0.1 to 0.0001 mg mL-1 , resulting in a correlation coefficient of 0.99998. The values of the detection limit and of the quantification limit are 0.00048 mg mL-1 and 0.00148 mg mL-1, respectively. The method proposed allowed accurate (with a relative error of less than 2%) and precise (RSD values less than 2.0%) determination of famotidine content in pharmaceutical products and can be used for its rapid quantitative analysis.

scholarly journals A Simple, Rapid, Fluorometric Assay for Dopamine by In Situ Reaction of Boronic Acids and cis-Diol

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Xiaoxia Liu ◽  
Miaomiao Tian ◽  
Wenmei Gao ◽  
Jinzhong Zhao
Keyword(s):  
Low Cost ◽  
Boronic Acids ◽  
Emission Peak ◽  
Excitation Wavelength ◽  
Fluorescence Sensing ◽  
Serum Samples ◽  
Turn On ◽  
Rapid Reaction

An efficient, sensitive, and low-cost method has been developed for turn-on fluorescence sensing of dopamine (DA). The method relies on the rapid reaction of DA and 3-Hydroxyphenylboronic acid (3-HPBA) via specific recognition between boronic acids and cis-diol of DA in alkaline solution. The reaction product shows an excitation wavelength of 417 nm and the maximum emission peak at 470 nm. The proposed method allows the determination of DA in the range of 50 nM–25 μM, and the whole detection can be completed within 5 minutes. Furthermore, the presented approach has good selectivity and has been successfully applied to DA sensing in human serum samples, showing great potential in clinical diagnosis.

Reverse Phase Liquid Chromatographic Determination of Some Food Additives

1987 ◽  
Vol 70 (3) ◽  
pp. 578-582 ◽  
Author(s):  
Madduri Veerabhadrarao ◽  
Mandayam S Narayan ◽  
Omprakash Kapur ◽  
Chilukuri Suryaprakasa Sastry
Keyword(s):  
Acetic Acid ◽  
Benzoic Acid ◽  
Mobile Phase ◽  
Direct Method ◽  
Food Additives ◽  
Acid Water ◽  
Relative Standard ◽  
Acetic Acid Water ◽  
Liquid Chromatographic

Abstract Liquid chromatographic methods are described for the separation and determination of non-nutritive sweeteners, namely, acesulfame, aspartame, saccharin, and dulcin; preservatives such as benzoic acid and p-hydroxybenzoic acid; and caffeine and vanillin in ready-toserve beverages, ice candy, ice cream, squash beverage, tomato sauce, and dry beverage mix samples. These additives are separated on a ^Bondapak C18 column using methanol-acetic acid-water (20 + 5 + 75) as mobile phase and detected by UV absorption at 254 nm. Caffeine, vanillin, dulcin, and benzoic acid can be analyzed quickly by using a mobile phase of methanol-acetic acid-water (35 + 5 + 60). Aspartame can be separated in the presence of caffeine and vanillin by using the mobile phase pH 3 acetate buffer-methanol (95 + 5). Retention factors and minimum detectable limits are described. The percentage error and the percent relative standard deviation for 6 replicate samples ranged from 0.3 to 2.8 and from 1.64 to 3.60, respectively. Recovery of additives added to the foods named and analyzed by the direct method and by extraction ranged from 98.0 to 100.6% and from 91.6 to 101.8%, respectively. The proposed LC techniques are simple, rapid, and advantageous because all the additives can be detected in a single step, which makes it useful for the routine analysis of various food products.

scholarly journals IMPORTANCE OF THE OXIDATION REACTION OF SODIUM METAPERIODATE FOR SPECTROPHOTOMETRIC ASSAY OF RESERPINE

2004 ◽  
Vol 72 (2) ◽  
pp. 121-129
Author(s):  
D. K. Singh ◽  
Archana Sahu
Keyword(s):  
Acetic Acid ◽  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Spectrophotometric Method ◽  
Oxidation Reaction ◽  
Spectrophotometric Assay ◽  
Sodium Metaperiodate ◽  
Relative Standard ◽  
Sensitive Spectrophotometric Method

A new simple, accurate and reasonably sensitive spectrophotometric method is described for the determination of reserpine based on the oxidation with sodium metaperiodate in the presence of acetic acid and coupling with 3-methyl-2-benzo thiazolinone hydazone hydrochloride (MBTH) to form highly blue coloured product showing maximum absorbance at 630 nm. Beer's law is obeyed in the range 0.2–1.6 µg ml−1. The relative standard deviation was found to be less than 1%. The proposed method can be applied for the estimation of reserpine in tablets with no evidence of interference from excipients.

Conductometric and Colorimetric Determination of Volatile Acidity of Vinegars by Flow-Injection Analysis

1991 ◽  
Vol 74 (2) ◽  
pp. 346-350 ◽  
Author(s):  
Matthieu Tubino ◽  
Flavio G Barros
Keyword(s):  
Acetic Acid ◽  
Colorimetric Determination ◽  
Bromocresol Purple ◽  
Water Stream ◽  
Ptfe Membrane ◽  
Volatile Acidity ◽  
Relative Standard ◽  
Significant Difference ◽  
Membrane Separator

Abstract Recent methods for determination of the volatile acidity of vinegars are relatively slow (about 40 mln) and involve techniques subject to a variety of errors (ca 2.5%). The present paper describes a method that provides results in a shorter time (ca 2 mln, Including dilution), with a smaller relative error rate (ca 1%). Conductometric analysis consists of the Injection of the sample In a deionlzed water stream that then flows past a PTFE membrane separator. Acetic acid diffuses through the membrane to another deionlzed water stream that passes through a conductivity cell. Colorimetric analysis also consists of sample injection into a deionlzed water stream that passes through the same PTFE membrane separator. However, the acetic acid diffuses into a bromocresol purple solution stream at pH 7. This solution passes through a flow cell In a spectrophotometer set at 540 nm. Before injection, samples were treated with hydrogen peroxide to ensure complete oxidation of sulfite to sulfate. Results of the proposed method were also compared with another similar method. At a 95% confidence level, the statistical t-test Indicates no significant difference between them. Typical estimates of the relative standard deviations obtained with the new methods are ca 1%. Analyses were performed with red and white wine vinegars.

scholarly journals Simultaneous Determination of Six Major Constituents of the Herbal Formula Insampaedok-san Using HPLC-PDA

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Chang-Seob Seo ◽  
Jung Hoon Kim ◽  
Hyeun-Kyoo Shin
Keyword(s):  
Acetic Acid ◽  
High Performance ◽  
Gradient Elution ◽  
High Performance Liquid Chromatographic ◽  
Aqueous Acetic Acid ◽  
Liquid Chromatographic Method ◽  
Relative Standard ◽  
Photodiode Array ◽  
Liquid Chromatographic

A simple, rapid, and accurate high-performance liquid chromatographic method was applied to the quantitative analysis of six components of a traditional herbal formulation, Insampaedok-san (ISPDS): liquiritin (1), ferulic acid (2), naringin (3), hesperidin (4), neohesperidin (5), and glycyrrhizin (6). The six components were separated within 35 min using a Gemini C18 column maintained at 40°C. The mobile phase was composed of 1.0% (v/v) aqueous acetic acid (A) and 1.0% (v/v) acetic acid in acetonitrile (B) by gradient elution. The flow rate was 1.0 mL/min and the detector was a photodiode array (PDA) set at 254, 280, and 320 nm. The calibration curves showed good linearity (R2=1.0000) for different concentration ranges. The recovery of each component was in the range of 92.62%–105.96%, with a relative standard deviation (RSD) of less than 4.0%. The RSDs for intra- and interday precision were 0.04%–1.70% and 0.06%–2.56%, respectively. The concentration of each of the six components of ISPDS was in the range 0.72–9.88 mg g−1.

scholarly journals Utilization of hydralazine hydrochloride in the Potentiometric Determination of Osmium(VIII): Analysis of Binary and Ternary Mixtures

2001 ◽  
Vol 69 (4) ◽  
pp. 367-374
Author(s):  
A. Amin ◽  
H. Saleh
Keyword(s):  
Acetic Acid ◽  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Ternary Mixtures ◽  
Indicator Electrode ◽  
Practical Applications ◽  
Relative Standard ◽  
Binary And Ternary Mixtures ◽  
Hydralazine Hydrochloride

A simple, rapid and accurate potentiolnetric method is described for tliedetermination of Os(VIII) in tlie co~icentrationr ange 0.4-4.0 mg/ml. Tlie method isbased on tlie addition of hydralazine hydrochloride to Os(VIII) to reduce it to Os(IV). The excess of hydralazine hydrocliloridew as oxidized by iodine dissolved ill acetic acid. The liberated iodide was then potentiometrically titrated against mercury(II) using silver amalgam as the indicator electrode. The potential of this method for sime- microdetermination is important in practical applications where tlie above reaction should proceed quantitatively towards completion. The relative standard deviation for six replicate deterinination of osmium(VIII) in binary andternary mixtures without the need for extraction or heating.

Determination of Fluorine in the Atmosphere Surrounded the Yellow Phosphorous Enterprise Using Ion Chromatography

2014 ◽  
Vol 507 ◽  
pp. 773-776
Author(s):  
Xin Yuan ◽  
Sen Lin Tian ◽  
Ming Jiang ◽  
Rong Rong Miao ◽  
Qian Wang ◽  
...  
Keyword(s):  
Ion Chromatography ◽  
Linear Response ◽  
Standard Addition ◽  
Peak Height ◽  
Yellow Phosphorus ◽  
Relative Standard ◽  
Sensitivity And Selectivity ◽  
R Value ◽  
Calm Wind

Ion chromatography (IC) method was applied to detection of fluorine in the atmosphere calm wind conditions at the area around the yellow phosphorus enterprise. The results indicated that the recovery of standard addition of Fluroide is 96.7%~100.6%. It gives a linear response of chromatographic peak height with respect to the fluoride in the range of 1~25 μg/mL, and the coefficient correlations R value is 0.9994. The concentration of Fluorine in the surrounding of yellow phosphorus enterprise ranging from 100~1500 m varies from 0.641~0.070 mg/m3. The relative standard deviation (RSD) of this method is between 2.10%~0.50%. This method is sensitivity and selectivity, low disturbance, and it is considered as a promising method for the detection of Fluorine surrounded yellow phosphorus enterprise.

Determination of Phenoxy Acid Herbicides in Cereals Using High-Performance Liquid Chromatography–Tandem Mass Spectrometry

2019 ◽  
Vol 82 (7) ◽  
pp. 1160-1165 ◽  
Author(s):  
TAO GUO ◽  
XIAOLI WANG ◽  
HAIFENG WANG ◽  
YUFEN HU ◽  
SHIYONG ZHANG ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Acetic Acid ◽  
High Performance ◽  
Tandem Mass ◽  
Chromatography Tandem Mass Spectrometry ◽  
Relative Standard ◽  
Liquid Chromatography Tandem Mass ◽  
Phenoxy Acid Herbicides ◽  
Acid Herbicides

ABSTRACTAn effective method for determination of multiple residues of phenoxy acid herbicides in cereals was developed. A QuEChERS (quick, easy, cheap, effective, rugged, and safe) technique coupled with high-performance liquid chromatography–tandem mass spectrometry (HPLC-MS/MS) was optimized for the analysis of phenoxy acid herbicides in rice, corn, and wheat. The limits of detection in the experiment were 0.0500 μg/kg for 4-(2,4-dichlorophenoxy)acetic acid, (4-chloro-2-methylphenoxy)acetic acid, (2,4,5-trichlorophenoxy)acetic acid, and 2-(2,4-dichlorophenoxy)propionic acid and 0.300 μg/kg for 4-(2,4-dichlorophenoxy)butyric acid and 3,6-dichloro-2-methoxybenzoic acid. The relative standard deviation of intraday and interday precision for the six phenoxy acid herbicides was less than 6.61%, and accuracy was 96.3 to 107%. Extraction recovery for phenoxy acid herbicides was 73.8 to 115%, with relative standard deviations of less than 12.1% at three spiking levels (1.00, 4.00, and 20.0 μg/kg). These results indicate that QuEChERS sample preparation with HPLC-MS/MS analysis is a rapid, reliable, highly sensitive, and specific tool for the determination of phenoxy acid herbicide residues in cereals.HIGHLIGHTS

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