Development of Rapid Colorimetric Assay for Detection of Gluconic Acid Using Iron(Ⅱ) and Indigo Carmine

2020 ◽  
Vol 42 (4) ◽  
pp. 525-525
Author(s):  
Yifeng Lan Yifeng Lan ◽  
Lixiang Zuo Lixiang Zuo ◽  
Yangyang Zhou Yangyang Zhou ◽  
Yanli Wei and Chuan Dong Yanli Wei and Chuan Dong

In this work, a simple and rapid spectrophotometric method, which is based on the fact that Iron(Ⅱ) -gluconic acid complex as a kind of reducing agent deterioration of indigo carmine dyes, was developed to detect gluconic acid in food. Under the optimal experimental condition, a linear range of 3.6 M to 900 M was obtained for gluconic acid with a limit of detection of 1.1 μM. The colorimetric method was rapid and robust with a low cost and can be applied to gluconic acid detection in food samples.

1987 ◽  
Vol 33 (10) ◽  
pp. 1874-1878 ◽  
Author(s):  
A Lopez-Anaya ◽  
M Mayersohn

Abstract We describe a "high-performance" liquid-chromatographic method for separating and quantifying ascorbic acid (AA) and dehydroascorbic acid (DHA) in plasma and urine. We used a reversed-phase C18 column with an ion-pair reagent and detected the analytes by post-column reaction with 4,5-dimethyl-o-phenylenediamine to form a fluorescent derivative (measured at excitation and emission wavelengths of 365 and 440 nm, respectively). Isoascorbic acid (IA) is the internal standard. Retention times for DHA, AA, and IA are 5.6, 15.5, and 19.9 min, respectively. Between-day CVs for AA in plasma in concentrations of 8 and 20 mg/L were 9% and 7%, respectively. The limit of detection is 10 and 4 ng for AA and DHA, respectively. Results by the present method and the methoxyaniline colorimetric method for AA are comparably accurate.


Sensors ◽  
2018 ◽  
Vol 18 (8) ◽  
pp. 2679 ◽  
Author(s):  
Zheng-Jun Xie ◽  
Xian-Yu Bao ◽  
Chi-Fang Peng

A new colorimetric detection of methylmercury (CH3Hg+) was developed, which was based on the surface deposition of Hg enhancing the catalytic activity of gold nanoparticles (AuNPs). The AuNPs were functionalized with a specific DNA strand (HT7) recognizing CH3Hg+, which was used to capture and separate CH3Hg+ by centrifugation. It was found that the CH3Hg+ reduction resulted in the deposition of Hg onto the surface of AuNPs. As a result, the catalytic activity of the AuNPs toward the chromogenic reaction of 3,3,5,5-tetramethylbenzidine (TMB)-H2O2 was remarkably enhanced. Under optimal conditions, a limit of detection of 5.0 nM was obtained for CH3Hg+ with a linear range of 10–200 nM. We demonstrated that the colorimetric method was fairly simple with a low cost and can be conveniently applied to CH3Hg+ detection in environmental samples.


Energies ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3967
Author(s):  
Jungsoon Park ◽  
Hee-Chul Eun ◽  
Seonbyeong Kim ◽  
Changhyun Roh ◽  
So-Jin Park

The aim of nuclear facility decommissioning is to make local settlements safe, sustainable and professedly acceptable. The challenges are the clean-up of the nuclear site and waste management. This means a definite promise in terms of safety and security, taking into account social and environmental accountability. There is an essential need to develop safe and efficient methods for nuclear decommissioning. Thus, chemical decontamination technology is of great significance to the decommissioning of nuclear energy facilities. In particular, chemical decontamination technology is applicable to the pipelines and internal loop. The iron-rich oxides, such as Fe3O4 or NiOFe2O3, of a nuclear power plant should have sound decontamination follow-through and should put through a very small amount of secondary waste. It is important to be able to detect and quantify hydrazine in decontamination situations with high sensitivity and selectivity. A colorimetric assay is a technique used to determine the concentration of colored compounds in a solution. However, detecting targeted species rapidly and easily, and with high sensitivity and specificity, is still challenging. Here, the catalytic reaction of oxidants in the p-dimethylaminobenzaldehyde and hydrazine reaction is elucidated. Oxidants can catalyze the reaction of hydrazine and p-dimethylaminobenzaldehyde to form an azine complex such as p-dimethylaminobenzaldazine, with high selectivity and sensitivity within 30 min at ambient temperatures. In the absence of an oxidant such as iron or hydrogen peroxide no detectable colorimetric change was observed by the reaction of p-dimethylaminobenzaldehyde and hydrazine unless an external oxidant was present in the system. In this study, we demonstrated a colorimetric method for the sensitive detection of hydrazine decomposition in the chemical decontamination process. Furthermore, the colorimetric response was easy to monitor with the unaided eye, without any sophisticated instrumentation. This method is thus suitable for on-site detection of contamination in a nuclear facility. In addition, this colorimetric method is convenient, non-invasive, free of complex equipment, and low-cost, making it possible to analyze hydrazine in industrial nuclear facilities. The proposed method was successfully applied to the determination of hydrazine decomposition in the nuclear decontamination process.


2017 ◽  
Vol 16 (1) ◽  
pp. 37-42
Author(s):  
Lyudmyla M Antypenko ◽  
Vitaliy A Solodovnyk

A simple and low-cost UV-spectrophotometric method has been developed and validated for the quantification of Octopirox in bulk. The linearity was found at 307 ± 1 nm in 10-50 ?g/ml solution of ethanol-water (1:3, v:v) with r2 = 0.99. The limit of detection was found to be 1.18 µg/ml, while the limit of quantification was 3.58 µg/ml. The method was validated for linearity, accuracy, precision, range, ruggedness and robustness.Dhaka Univ. J. Pharm. Sci. 16(1): 37-42, 2017 (June)


Toxins ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 120
Author(s):  
Reuven Rasooly ◽  
Paula Do ◽  
Bradley Hernlem

Abrin is a highly potent and naturally occurring toxin produced in the seeds of Abrus precatorius (Rosary Pea) and is of concern as a potential bioterrorism weapon. There are many rapid and specific assay methods to detect this toxic plant protein, but few are based on detection of toxin activity, critical to discern biologically active toxin that disables ribosomes and thereby inhibits protein synthesis, producing cytotoxic effects in multiple organ systems, from degraded or inactivated toxin which is not a threat. A simple and low-cost CCD detector system was evaluated with colorimetric and fluorometric cell-based assays for abrin activity; in the first instance measuring the abrin suppression of mitochondrial dehydrogenase in Vero cells by the MTT-formazan method and in the second instance measuring the abrin suppression of green fluorescent protein (GFP) expression in transduced Vero and HeLa cells. The limit of detection using the colorimetric assay was 10 pg/mL which was comparable to the fluorometric assay using HeLa cells. However, with GFP transduced Vero cells a hundred-fold improvement in sensitivity was achieved. Results were comparable to those using a more expensive commercial plate reader. Thermal inactivation of abrin was studied in PBS and in milk using the GFP-Vero cell assay. Inactivation at 100 °C for 5 min in both media was complete only at the lowest concentration studied (0.1 ng/mL) while treatment at 63 °C for 30 min was effective in PBS but not milk.


2009 ◽  
Vol 6 (s1) ◽  
pp. S163-S170 ◽  
Author(s):  
R. Singh Gujral ◽  
S. Manirul Haque ◽  
P. Shanker

An accurate and validated spectrophotometric method was developed for the determination of gabapentin. This is simple, sensitive and low cost UV spectrophotometric method. The method is based on the direct measurement of the native absorbance of the drug. The detection was done at 210 nm. The method was linear in the range of 0.25 - 3.5 µ g/mL with correlation coefficient of 0.9999. It is validated according to the ICH guidelines with respect to linearity, selectivity, accuracy and precision, limit of quantitation and limit of detection. The method has been applied to assess gabapentin in pharmaceutical formulations with good accuracy and precision and relatively free of interference from coexisting substances.


2020 ◽  
Vol 2020 ◽  
pp. 1-6
Author(s):  
Rute C. Martins ◽  
Ana M. Pereira ◽  
Elisabete Matos ◽  
Luisa Barreiros ◽  
António J. M. Fonseca ◽  
...  

Zinc is an essential trace element for animals in several biological processes, particularly in energy production, and it is acquired from food ingestion. In this context, a microplate-based fluorimetric assay was developed for simple, fast, and low-cost determination of zinc in pet food using 2,2′-((4-(2,7-difluoro-3,6-dihydroxy-4aH-xanthen-9-yl)-3-methoxyphenyl)azanediyl)diacetic acid (FluoZin-1) as fluorescent probe. Several aspects were studied, namely, the stability of the fluorescent product over time, the FluoZin-1 concentration, and the pH of reaction media. The developed methodology provided a limit of detection of 1 μg L−1 in sample acid digests, with a working range of 10 to 200 μg L−1, corresponding to 100–2000 mg of Zn per kg of dry dog food samples. Intraday repeatability and interday repeatability were assessed, with relative standard deviation values < 3.4% (100 μg L−1) and <11.7% (10 μg L−1). Sample analysis indicated that the proposed fluorimetric assay provided results consistent with ICP-MS analysis. These results demonstrated that the developed assay can be used for rapid determination of zinc in dry dog food.


2019 ◽  
Author(s):  
◽  
Nonhlazeko Loveday Nxumalo

Water is one of the most valuable and crucial of life and therefore accurate monitoring and assessment of water resources for sustainability is imperative. Conventional water investigation includes manual gathering of tests, their transportation and resulting examination in the research center. This is time and labour-intensive, costly and requires exceptionally qualified personnel. Sovereign of this procedure empowers more continuous examination, sparing time and cash for analysts, ventures and administering bodies. Consequently, there is requirement for advancement of minimal effort ecological microfluidic paper-based expository gadget that is fundamental for compelling administration of our profitable water assets. This will address the huge and growing demand for low-cost ammonia sensors as legislation becomes more stringent and as more frequent monitoring becomes essential for legislative compliance. Subsequently, this thesis reports on the development of a low-cost, colorimetric, wax- printed microfluidic paper-based analytical device (µPAD) to detect ammonia in industrial wastewaters. Microfluidic innovation was utilized to facilitate the examination of analytes on the colorimetric explanatory techniques onto a convenient detecting gadget. This therefore empowers the blending of little volumes of analytes with synthetic reagents to form a coloured/hued product in the sight of the analyte of interest. The µPAD fabricated was an oval shaped pattern which was designed on Corel draw software. The hydrophilic segments were made by printing a chromatographic paper with hydrophobic paper sizing agents utilizing a standard Xerox wax printer (Xerox colorqube 8570). The quantification of ammonia in wastewater was performed on the µPADs using two typical colorimetric methods namely, Nessler reagent and Salicylate. The reaction of ammonia with the Nessler reagent resulted in a brown or intense yellow colour whereas with the salicylate method, the final colour was green. For both methods, the colour intensity increased proportionally with the analyte concentration, and all images of the μPADs were captured and colorimetrically analyzed with ImageJ software for quantification. The analytical performances of the µPAD were linear from 0 to 5 mg L-1 with a limit of detection of 3.37 mg L-1 and 3.20 mg L-1 for the Nessler vii reagent and salicylate methods respectively. The validity and accuracy of aforementioned methods was supported by the standard UV Visible spectrophotometric method and applied to the measurement of wastewater effluent samples. Wastewater samples were analyzed and the results obtained were similar to those obtained with a spectrophotometric method, demonstrating that the µPAD is suitable to determine ammonia in wastewater.


Water SA ◽  
2020 ◽  
Vol 46 (3 July) ◽  
Author(s):  
Nonhlazeko Loveday Nxumalo ◽  
Lawrence Mzukisi Madikizela ◽  
Hendrik Gert Kruger ◽  
Stanley Chibuzor Onwubu ◽  
Phumlane Selby Mdluli

Ammonia is a toxic pollutant increasingly found in urban and industrial wastewater and unprotected surface water. Industry discharges and fertilizer run-off release ammonia into sewers and streams, overloading wastewater treatment plants and causing fish deaths in surface water such as rivers, sea and lakes. The purpose of this study was to develop and evaluate the effectiveness of the microfluidic paper-based device (µPAD) for the quantification of ammonia in wastewater. The µPAD fabricated had an oval-shaped pattern which was designed using CorelDraw software. The hydrophilic zones were created by printing a chromatographic paper with a Xerox wax printer (Xerox colorqube 8570). The modified version of the colorimetric method using Nessler reagent was combined with microfluidic technologies to create a low-cost monitoring system for detection of ammonia in wastewater. The method allows for ammonia determination in the range of 0–5 ppm (mg/L) with a limit of detection of 3.34 ppm. This study indicated that a µPAD was successfully used to quantify the concentration of ammonia in wastewater.


2009 ◽  
Vol 45 (1) ◽  
pp. 121-126 ◽  
Author(s):  
Ketylin Fernanda Migliato ◽  
Elisângela Simões de Carvalho ◽  
Luis Vitor Silva do Sacramento ◽  
João Carlos Palazzo de Mello ◽  
André Rolim Baby ◽  
...  

A precise, accurate and low cost spectrophotometric method was developed and validated for routine determination of total polyphenols, as pyrogallic acid equivalents, from the percolated and lyophilized extract of Syzygium cumini (L.) Skeels fruits. Validation was assessed experimentally and data were rigorously treated by statistical analysis. Analytical parameters were: linearity, interval (range), precision and recovery/accuracy, limit of detection (LOD, μg mL-1) and limit of quantification (LOQ, μg mL-1). The visible spectrophotometric method presented linearity (r² = 0.9979 ± 0.0010) over the concentration range 0.25-7.5 μg mL-1 of standard pyrogallic acid, precision < 2.918171%, recovery/accuracy ranging from 96.228693 to 107.17701%, LOD = 0.21 μg mL-1 and LOQ = 0.64 μg mL-1.


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