scholarly journals Fabrication of an Immobilized Polyelectrolite Complex (PEC) Membrane from Pectin-Chitosan and Chromoionophore ETH 5294 for pH-Based Fish Freshness Monitoring

Coatings ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 88
Author(s):  
Eka Safitri ◽  
Zatul Omaira ◽  
Nazaruddin Nazaruddin ◽  
Irfan Mustafa ◽  
Sitti Saleha ◽  
...  
Keyword(s):  
Accurate Determination ◽  
Active Material ◽  
Ph Sensor ◽  
Wavelength Region ◽  
Trial And Error ◽  
Optimum Conditions ◽  
Relative Standard ◽  
Optimum Wavelength ◽  
Optical Ph Sensor

Considering the significance of its demand around the world, the accurate determination of fish freshness with a simple and rapid procedure has become an interesting issue for the fishing industry. Hence, we aimed to fabricate a new optical pH sensor based on a polyelectrolyte (PEC) membrane of pectin–chitosan and the active material chromoionophore ETH 5294. A trial-and-error investigation of the polymer compositions revealed that the optimum ratio of pectin to chitosan was 3:7. With an optimum wavelength region (λ) at 610 nm, the constructed sensor was capable of stable responses after 5 min exposure to phosphate-buffered solution. Furthermore, the obtained sensor achieved optimum sensitivity when the PBS concentration was 0.1 M, while the relative standard deviation values ranged from 2.07 to 2.34%, suggesting good reproducibility. Further investigation revealed that the sensor experienced decreased absorbance of 16.67–18.68% after 25 days of storage. Employing the optimum conditions stated previously, the sensor was tested to monitor fish freshness in samples that were stored at 4 °C and ambient temperature. The results suggested that the newly fabricated optical sensor could measure pH changes on fish skin after 25 h storage at room temperature (pH 6.37, 8.91 and 11.02, respectively) and 4 °C (pH 6.8, 7.31 and 7.92, respectively).

Rapid Determination of Sulfite by Flow Injection Analysis Based on Fuchsin′s Addition

2013 ◽  
Vol 295-298 ◽  
pp. 950-953 ◽  
Author(s):  
Dong Yuan ◽  
Da You Fu ◽  
Wen Yuan Tan
Keyword(s):  
Flow Injection ◽  
Addition Reaction ◽  
Rapid Determination ◽  
Sampling Rate ◽  
Optimum Conditions ◽  
Linear Calibration ◽  
Relative Standard ◽  
Replicate Measurements ◽  
Good Agreement

A rapid spectrophotometric method for flow injection determination of sulfite in tan wastewater is described. The proposed method was based on the addition reaction of sulfite with fuchsin in Na2B4O7-NaOH medium. The optimum conditions allow a linear calibration range of 0.01-1.20 μg ml-1 SO32-. The detection limit is 0.0023μg ml-1 (S/N=3), and the relative standard deviation for night replicate measurements is 1.1% for 0.5μg ml-1 of sulfite. The sampling rate is 60 samples h-1. The procedure has been applied to the determination of sulfite in tan wastewater. The results were in good agreement with those obtained by pararosaniline method.

scholarly journals Preparation and Characterization of a Pectin Membrane-Based Optical pH Sensor for Fish Freshness Monitoring

Biosensors ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 60 ◽  
Author(s):  
Uswatun Hasanah ◽  
Mita Setyowati ◽  
Rustam Efendi ◽  
Muslem Muslem ◽  
Nor Diyana Md Sani ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Response Time ◽  
Relative Standard Deviation ◽  
Ph Sensor ◽  
Sensor Response ◽  
Relative Standard ◽  
Optical Ph Sensor

In a simple and instant procedure for detecting fish freshness, a hydrogel and hydrophilic pectin matrix membrane was used successfully as an optical pH sensor by immobilizing the chromoionophore ETH 5294 (CI), which is very selective and sensitive for the membrane. The Pe/CI optical pH sensor exhibited excellent linearity between pH 5 and pH 9, with a sensor response time of 5 min and reproducibility of 1.49% relative standard deviation (RSD). The sensor showed response stability for 15 days and a response reduction of 8.6%. The sensor’s capability was demonstrated by the detection of fish freshness for 17 days at 4 °C.

scholarly journals Determination of Organophosphorous Pesticide Phosphamidon in Environmental Water with Luminol Chemiluminescence Detection

2009 ◽  
Vol 92 (3) ◽  
pp. 914-918 ◽  
Author(s):  
Aifang Li ◽  
Xiaoyu Liu ◽  
Juan Kong ◽  
Haoyu Hu ◽  
Linghui Sun ◽  
...  
Keyword(s):  
Sodium Dodecyl ◽  
Sodium Dodecyl Benzene Sulfonate ◽  
Environmental Water ◽  
Optimum Conditions ◽  
Chemiluminescence Method ◽  
Luminol Chemiluminescence ◽  
Relative Standard ◽  
Organophosphorous Pesticide ◽  
Dodecyl Benzene Sulfonate

Abstract A novel chemiluminescence method has been developed for the determination of the organophosphorous pesticide phosphamidon in environmental water samples, based on the reaction of phosphamidon with luminolH2O2 in an alkaline medium using sodium dodecyl benzene sulfonate as the enhancer. Under optimum conditions, the increased chemiluminescence intensity was proportional to the concentration of phosphamidon in the range of 0.011.0 g/mL and the detection limit was 0.0038 g/mL (3). The relative standard deviation was <2 for 0.5 g/mL phosphamidon (n = 11). The proposed method was applied to the determination of phosphamidon residue in an environmental water sample with satisfactory results. Further study was focused on the mechanism of phosphamidon, and a possible mechanism was proposed.

2-Monochloropropanediol (2-MCPD), 3-Monochloropropanediol (3-MCPD), and Glycidol in Infant and Adult/Pediatric Nutritional Formula: Single-Laboratory Validation, First Action 2018.12

2019 ◽  
Vol 102 (4) ◽  
pp. 1205-1220 ◽  
Author(s):  
Jan Kuhlmann
Keyword(s):  
Fatty Acid ◽  
Infant Formula ◽  
Edible Oils ◽  
Accurate Determination ◽  
Fatty Acid Esters ◽  
Method Performance ◽  
Relative Standard ◽  
Single Laboratory ◽  
Acid Esters

Abstract Background: Fatty acid esters of glycidol, 2-Monochloropropanediol (MCPD), and 3-MCPD are heat-induced foodborne processing contaminants with possible adverse health effects. These compounds occur frequently in refined edible oils. Consequently, glycidyl esters and 2- and 3-MCPD esters might also be present in foods that contain refined edible oils. Objective: This manuscript describes the single-laboratory validation of an analytical method for the quantitative determination of glycidol, 2-MCPD, and 3-MCPD present as fatty acid esters or as free 2- or 3-MCPD in infant and adult/pediatric nutritional formula. Methods: Technically, the presented method is based on the combination of a Heat-Ultrasound Pressure-supported Solvent Extraction and a GC–MS determination of glycidol, 2-MCPD, and 3-MCPD. From a chemical perspective, the method includes an alkaline catalyzed transesterification, conversion of the unstable glycidol into monobromopropanediol, and the parallel derivatization of all analytes with phenylboronic acid. Results: Validation results showed that method linearity for all analytes in powdered and liquid infant formula ranged from 0.9981 to 0.9999 (n = 18). Repeatability relative standard deviation values for concentration levels between 1.3 μg/kg and 331 μg/kg were in the range of 1 to 12%. Relative recoveries were found to be between 93 and 107%. The analytes were quantifiable down to 5–10 μg/kg in powdered samples and 1–2 μg/kg in liquid samples. Conclusions: The reported results met actual AOAC Standard Method Performance Requirements. Highlights: In terms of consumer protection, the presented method is a novel approach for the sensitive and accurate determination of glycidol, 2-MCPD, and 3-MCPD in infant formula and related foodstuffs.

scholarly journals A Highly Sensitive Spectrofluorometric Method for the Determination of a New Antidepressant Drug, Reboxetine, in Tablets

2006 ◽  
Vol 89 (4) ◽  
pp. 972-975 ◽  
Author(s):  
ArmaĞan Önal
Keyword(s):  
Antidepressant Drug ◽  
Fluorescence Emission ◽  
Calibration Graph ◽  
Control Analysis ◽  
Optimum Conditions ◽  
Highly Sensitive ◽  
Relative Standard ◽  
Spectrofluorometric Method ◽  
Interday Precision

Abstract A highly sensitive, selective, and rapid spectrofluorometric method has been developed for the determination of reboxetine (REB) in tablets. The method is based on derivatization with 7-chloro-4-nitrobenzofurazan. The product showed an absorption maximum at 476 nm and a fluorescence emission peak at 533 nm in ethyl acetate. The optimum conditions of the reaction were investigated, and it was found that the reaction proceeded quantitatively at pH 8.5, 70C in 5 min. The calibration graph is rectilinear over the range of 0.02-0.40 μg/mL. The relative standard deviation values for intraday and interday precision were 0.40-0.93 and 0.54-1.37%, respectively. The proposed method was applied to the assay of REB in tablets. Mean recovery of REB from the tablets ranged between 99.91-100.20%. The results were compared statistically with those obtained by a method reported in the literature. The method is sensitive, simple, and selective, and can be used for routine quality control analysis.

A method of high sensitivity and in situ determination of trace cobalt(II) in water samples with salicyl fluorone

2014 ◽  
Vol 70 (7) ◽  
pp. 1182-1187 ◽  
Author(s):  
Zhe Chen ◽  
Hua Li
Keyword(s):  
Flow Injection ◽  
Water Samples ◽  
High Sensitivity ◽  
Basic Solution ◽  
Optimum Conditions ◽  
Cetylpyridinium Bromide ◽  
Test Conditions ◽  
Relative Standard

Based on the sensitive reaction of Co(II) and salicyl fluorone with the presence of cetylpyridinium bromide in basic solution, a new method of flow injection micelle-solubilized spectrophotometry was developed for the determination of cobalt. The reaction was monitored for the absorbance of Co(II) at 540 nm. The reagents, flow injection variables and effects of foreign ions were investigated and the optimum conditions were established. At the optimum test conditions, the developed method provides a linearity range of 3–40 μg L−1 with a detection limit of 0.1 μg L−1 at about 60 h−1 sampling frequency. Relative standard deviation of 0.91, 0.95 and 0.89% were obtained for the determination of 3, 15 and 30 μg L−1 Co(II) solution. The proposed method has been successfully applied for analysis of trace amounts of cobalt in water samples.

scholarly journals Aqueous Two-Phase Systems: A New Approach for the Determination of Brilliant Blue FCF in Water and Food Samples

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Sabah Shiri ◽  
Tahere Khezeli ◽  
Shahram Lotfi ◽  
Sina Shiri
Keyword(s):  
Polyethylene Glycol ◽  
Standard Deviation ◽  
Food Samples ◽  
Brilliant Blue ◽  
Phase System ◽  
Optimum Conditions ◽  
Two Phase ◽  
Brilliant Blue Fcf ◽  
Relative Standard

A novel, simple, and more sensitive spectrophotometric procedure has been developed for the determination of brilliant blue FCF in water and food samples by an aqueous two-phase system (ATPS). In this method, adequate amount of polyethylene glycol/ sodium carbonate (PEG-4000/Na2CO3) was added to aqueous solution for formation of a homogeneous solution. To the mixture solution, suitable amount ofNa2CO3was added, the mixture solution was shaken until the salt was dissolved, and then it was separated into two clear phases easily and rapidly. The target analyte in the water sample was extracted into the polyethylene glycol phase. After extraction, measuring the absorbance at 634 nm was done. The effects of different parameters such as polyethylene glycol (type and concentration), pH, salt (type and amount), centrifuge time, and temperature on the ATPS of dye was investigated and optimum conditions were established. Linear calibration curves were obtained in the range of 0.25–750 ng/mL for brilliant blue FCF under optimum conditions. Detection limit based on three times the standard deviation of the blank (3Sb) was 0.12 ng/mL. The relative standard deviation (RSD) for 400 ng/mL was 3.14%. The method was successfully applied to the determination of brilliant blue FCF in spiked samples with satisfactory results. The relative recovery was between 96.0 and 102.2%.

A spectrofluorimetric method for the determination of acitretin in pharmaceuticals

2009 ◽  
Vol 63 (4) ◽  
Author(s):  
Suling Feng ◽  
Yi Zhang ◽  
Jing Fan
Keyword(s):  
Fluorescence Spectra ◽  
Hplc Method ◽  
Relative Fluorescence Intensity ◽  
Optimum Conditions ◽  
Green Fluorescence ◽  
Spectrofluorimetric Method ◽  
Highly Sensitive ◽  
Relative Standard ◽  
Effects Of Ph

AbstractA simple, rapid, and highly sensitive spectrofluorimetric method for the determination of acitretin was developed based on the strong green fluorescence of acitretin. Influence of organic solvents on the fluorescence spectra of acitretin was studied. Effects of pH, standing time, and foreign ions on the determination of acitretin were also examined. Under the optimum conditions, linear relationship between the relative fluorescence intensity and the concentration of acitretin in the range of 30.0–1100 ng mL−1 was obtained. Detection limit of this method is 9.56 ng mL−1 for acitretin. Relative standard deviation for the determination of 480 ng mL−1 of acitretin was 1.70 %. This method was used for the determination of acitretin in pharmaceuticals and the results were compared with those obtained by the HPLC method.

Cloud Point Extraction-Fluorimetric Combined Methodology for the Determination of Magnolol

2013 ◽  
Vol 699 ◽  
pp. 34-39
Author(s):  
Li Liu ◽  
Xia Shi Zhu
Keyword(s):  
Standard Deviation ◽  
Detection Limit ◽  
Cloud Point ◽  
Relative Standard Deviation ◽  
Cloud Point Extraction ◽  
Calibration Graph ◽  
Optimum Conditions ◽  
Relative Standard ◽  
Triton X

A new Triton X-114 cloud point extraction combined with fluorometry method for analysis of magnolol in drug samples was developed. Under the optimum conditions, the calibration graph was linear in the range of 2.0-150.0ng/mL of magnolol in the initial solution with r = 0.9998. Detection limit (DL) was 0.03ng/mL (S/N=3) and the relative standard deviation (RSD) for 20.0ng/mL of magnolol was 2.79%(n=11). The method was successfully applied for the determination of magnolol in drug samples with satisfactory results.

Chemiluminescence Enhancement Effect for the Determination of Acetaminophen with the Catalysis of Manganese Deuteroporphyrin (Mn(III)DP)

2013 ◽  
Vol 575-576 ◽  
pp. 249-252 ◽  
Author(s):  
Ying Jun Chao ◽  
Liang Xiao Xie ◽  
Wei Cao
Keyword(s):  
Detection Limit ◽  
Pharmaceutical Preparations ◽  
Peak Height ◽  
Enhancement Effect ◽  
Optimum Conditions ◽  
Chemiluminescence Intensity ◽  
Relative Standard ◽  
Alkaline Conditions ◽  
Flow Injection Chemiluminescence

It is found thatManganese Deuteroporphyrin (Mn(Ⅲ)DP) can greatly enhance the chemiluminescence intensity of luminol-hydrogen peroxide system in alkaline conditions. Basing on that fact a flow injection chemiluminescence (CL) method has been developed for the determination of acetaminophen. With the peak height as a quantitative parameter applying optimum conditions, the relative CL intensity was linear with acetaminophen concentration in the range of 1.0×10-9～1.0×10-7 g/mL with a detection limit of 2.8×10-10 g/mL. The relative standard deviation (RSD) was 2.7% for 2.0 x10-8 g/mL acetaminophen (n = 11). The proposed method held low detection limit and was successfully applied to determination of acetaminophen in pharmaceutical preparations.

Sign in / Sign up

Export Citation Format

Share Document