scholarly journals L-Tryptophan as Fluorescent Probe for Determination of Folic Acid in Pharmaceutical Products

2019 ◽  
Vol 7 (2) ◽  
pp. 19-26
Author(s):  
Tara F. Tahir ◽  
Aryan F. Qader ◽  
Musher I. Salih ◽  
Essa Q. Rashid

A new fluorescent probe L-Tryptophan was reported for the determination of folic acid (FA), based on its quenching effect of the fluorescence intensity of L-Tryptophan. The concentration of folic acid was proportional to the quenched fluorescence intensity of L-Tryptophan at an emission wavelength of 365 nm in Britton– Robinson (BR) buffer solution of pH 7. Optimized conditions of pH, time, order of addition of the reagent, potential interferences, concentrations of L-Tryptophan and buffer were investigated. Folic acid was determined in a linear range of 2.0 to 16.0 μg ml-1 with a correlation coefficient R2 0.9974. The limits of detection LOD and quantification LOQ values were 0.09 μg ml-1 and 0.27 μg ml-1, respectively. The standard deviation (RSD) values for five replicated measurements of 2, 8, 16 μg ml-1 folic acid were between 0.23 % and 1.07%. This method is efficient for routine analysis and quality control assay as it is relatively interferences free.

2015 ◽  
Vol 7 (4) ◽  
pp. 1543-1548 ◽  
Author(s):  
Lixia Lu ◽  
Chuanxia Chen ◽  
Dan Zhao ◽  
Fan Yang ◽  
Xiurong Yang

The fluorescence intensity of folic acid enhanced significantly upon exposure to UV radiation with the addition of NO2−.


Author(s):  
Hesham Salem ◽  
Amany Abdelaziz ◽  
Aliaa Gamal ◽  
Ramy El Sabaa

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.


2019 ◽  
Vol 7 (2) ◽  
pp. 61 ◽  
Author(s):  
Tetsuhiro Tsujino ◽  
Kazushige Isobe ◽  
Hideo Kawabata ◽  
Hachidai Aizawa ◽  
Sadahiro Yamaguchi ◽  
...  

Although platelet-rich plasma (PRP) is now widely used in regenerative medicine and dentistry, contradictory clinical outcomes have often been obtained. To minimize such differences and to obtain high quality evidence from clinical studies, the PRP preparation protocol needs to be standardized. In addition, emphasis must be placed on quality control. Following our previous spectrophotometric method of platelet counting, in this study, another simple and convenient spectrophotometric method to determine platelet aggregation activity has been developed. Citrated blood samples were collected from healthy donors and used. After centrifugation twice, platelets were suspended in phosphate buffered saline (PBS) and adenosine diphosphate (ADP)-induced aggregation was determined using a spectrophotometer at 615 nm. For validation, platelets pretreated with aspirin, an antiplatelet agent, or hydrogen peroxide (H2O2), an oxidative stress-inducing agent, were also analyzed. Optimal platelet concentration, assay buffer solution, and representative time point for determination of aggregation were found to be 50–100 × 104/μL, PBS, and 3 min after stimulation, respectively. Suppressed or injured platelets showed a significantly lower aggregation response to ADP. Therefore, it suggests that this spectrophotometric method may be useful in quick chair-side evaluation of individual PRP quality.


2019 ◽  
Vol 102 (3) ◽  
pp. 801-809
Author(s):  
Ana Carolina Kogawa ◽  
Ana Elisa Della Torre Pires ◽  
Hérida Regina Nunes Salgado

Abstract Background: Atorvastatin, a lipid-regulating drug, was the best-selling drug in the world in the early 2000s. Thus, monitoring of this drug is important because it is accessible to a large portion of the population. In addition, its quality control is fundamental to provide quality medicines. Method of analysis can be the first step in the rational use of pharmaceuticals. Objective/Methods: In this context, a critical review of analytical methods present in the literature and official compendia for the pharmaceutical quality control of atorvastatin was made. Results: Among the analytical methods most used in the evaluation of atorvastatin, HPLC is highlighted, followed by HPLC coupled to MS, and spectrophotometry in UV. Tablets are the most studied pharmaceutical samples, and plasma is the most studied biological matrix. In the literature, studies with atorvastatin-based pharmaceutical products are more common than biological materials. Acetonitrile is the organic solvent most commonly used in the methods surveyed to evaluate atorvastatin. Conclusions: Currently, awareness of the impact that the analytical choice has on the health of the operator and the environment is growing. Therefore, the suitability of existing methods for the determination of atorvastatin can be made to adhere to the current analytical chemistry. In this way, the analytical, environmental, and human consciousness will remain united. Highlights: Although the literature shows interesting methods from an economic and environmental point of view, such as UV, Vis miniaturized, and TLC, they can still be improved to meet the requirements of the current sustainable analytical chemistry.


2011 ◽  
Vol 301-303 ◽  
pp. 361-365
Author(s):  
Mei Ding ◽  
Ying Jie Lei ◽  
Ou Yang Jie

In recent years, fluorescence spectrometry was widely used in quantitative determination of DNA. In this paper, a convenient synthesis of a new fluorescent 2-(2'- Chloro phenyl)- 5- (2'- hydroxyl phenyl)-1,3,4-oxadiazole (HOXD) was realized. Experimental data showed that fluorescence of HOXD could be quenched by DNA and the decreased fluorescence intensity of HOXD resulting from fluorescence quenching is proportional to DNA concentrations suggesting that HOXD could be used as a new fluorescent probe for quantitative determination of DNA. Optimal experimental conditions for DNA analysis were also studied in the paper.


2013 ◽  
Vol 830 ◽  
pp. 345-348
Author(s):  
Lin Gao ◽  
Sheng Jie Chen ◽  
Fang Chen ◽  
Wen Hong Zhou ◽  
Jun Long Yao

A simple, sensitive, green and low cost detection method based on the cloud point extraction (CPE) separation and spectrophotometry was proposed for the determination of lead. In pH=9.0 H3BO3 buffer solution, Pb(II) reacts with 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol (5-Br-PADAP) in the presence of Triton X-100 yielding a hydrophobic complex, which then is extracted into micro-volume surfactant-rich phase. The calibration graph was linear in the range of 20-400 µg/L (at 560 nm). Under the optimized conditions, the detection limits of 10.94 µg/L and the relative standard deviations(RSD) of 2.0% (n=5) for Lead(II) were found, respectively. The sensitivity and absorbance of this method are at least five times higher when compared with that of usual 5-Br-PADAP spectrophotometry without CPE, and the proposed method has been applied to the determination of Lead in environment water samples with satisfactory results.


The Analyst ◽  
2014 ◽  
Vol 139 (12) ◽  
pp. 2986-2989 ◽  
Author(s):  
Jiyoung Kim ◽  
Youngmi Kim

A water-soluble sulfonate-BODIPY dye1was developed for the selective detection of HOCl/OCl−in aqueous buffer solution. The probe, which displays extremely weak fluorescence owing to efficient photoinduced electron transfer (PeT) from the pendant catechol donor, responds to HOCl/OCl−through a dramatic enhancement of its fluorescence intensity.


2019 ◽  
Vol 186 (9) ◽  
Author(s):  
Yage Peng ◽  
Wenfei Dong ◽  
Le Wan ◽  
Xiaosai Quan

2007 ◽  
Vol 90 (1) ◽  
pp. 238-243 ◽  
Author(s):  
Qin Wei ◽  
Hongmin Ma ◽  
Caihong Duan ◽  
Jin Wang ◽  
Shuyuan Liu ◽  
...  

Abstract The fluorescence intensity of the trihydroxylphenylfluorone-molybdenum(VI) Mo(VI) complex is quenched by protein. Based on this, a novel method for protein assay in aqueous solution was developed. With pH 3.75 acetic acidsodium acetate buffer solution, in the presence of p-octyl polyethylene glycol phenyl ether microemulsion, the quenched fluorescence intensity is proportional to the concentration of bovine serum albumin (BSA) in the range of 07.00 μg/mL, and the detection limit of BSA is 5.65 ng/mL. There is no interference from amino acids and most metal ions. The method developed in this paper has been used for the successful determination of protein in human serum.


2019 ◽  
Vol 9 (3) ◽  
pp. 187-195 ◽  
Author(s):  
Somayeh Tajik ◽  
Hadi Beitollahi ◽  
Mohammad Reza Aflatoonian

Flower-like La3+/ZnO nanocomposite was facile synthesized. A simple and ultrasensitive sensor based on graphite screen printed electrode (SPE) modified by La3+/ZnO nanoflower was developed for the electrochemical determination of dopamine. The electrochemical behavior of dopamine was studied in 0.1 M phosphate buffer solution (PBS) using cyclic voltammetry (CV), chronoamperometry (CA) and differential pulse voltammetry (DPV). Compared with the unmodified graphite screen printed electrode, the modified electrode facilitates the electron transfer of dopamine, since it notably increases the oxidation peak current of dopamine. Also, according to CV results the maximum oxidation of dopamine on La3+/ZnO/SPE occurs at 150 mV which is about 140 mV more negative compared with unmodified SPE. Under optimized conditions, the modified electrode exhibited a linear response over the concentration range from 0.15 to 300.0 μM, with a detection limit of 0.08 μM (S/N = 3). The proposed sensor exhibited a high sensitivity, good stability and was successfully applied for dopamine determination in dopamine ampoule, with high recovery.


Sign in / Sign up

Export Citation Format

Share Document