scholarly journals Development of Biological Oxygen Demand Biosensor for Monitoring the Fermentation Industry Effluent

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Neelam Verma ◽  
Ashish Kumar Singh
Keyword(s):  
Response Time ◽  
Microbial Consortium ◽  
Oxygen Demand ◽  
Cell Biomass ◽  
Relative Standard ◽  
Close Proximity ◽  
Standard Solution ◽  
Standard Sample Solution ◽  
Industry Effluent

A biosensor was developed for the determination of BOD value of fermentation industry effluent. The developed biosensor was fabricated by immobilizing the microbial consortium on cellulose acetate (CA) membrane in close proximity to a DO probe electrode. The microbial consortium was harvested from the fermentation industry effluent. The BOD biosensor was calibrated by using a solution containing the equivalent amount of glucose/glutamic acid (GGA) as a standard sample solution. The response time was optimized by immobilizing different concentrations of cell biomass on CA membrane. Once the response time was optimized, it was used for determination of BOD of fermentation industry effluent. For analysis of fermentation industry effluent, the response time was observed 7 minutes with detection limit 1 mg/L. Good linear range with GGA standard solution was observed, 0.99 with relative standard deviation (RSD) <%. The observed BOD value by biosensor showed a good comparison with the conventional method for the determination of BOD.

scholarly journals Proficiency Testing of Eight French Laboratories in Using the AOAC Mouse Bioassay for Paralytic Shellfish Poisoning: Interlaboratory Collaborative Study

2000 ◽  
Vol 83 (2) ◽  
pp. 305-310 ◽  
Author(s):  
Martial LeDoux ◽  
Sherwood Hall ◽  
Madeleine Bohec ◽  
Bernard Charron ◽  
Magali Esnault ◽  
...  
Keyword(s):  
Water Solution ◽  
Collaborative Study ◽  
Paralytic Shellfish Poisoning ◽  
Mouse Bioassay ◽  
Shellfish Poisoning ◽  
Paralytic Shellfish ◽  
Relative Standard ◽  
Standard Solution ◽  
Overall Performance

Abstract In an interlaboratory study, 8 French laboratories were tested for their proficiency in using the AOAC mouse bioassay for paralytic shellfish poisoning (PSP). Each laboratory received 1 saxitoxin (STX) standard solution, 1 STX acidified water solution for determination of the titer, 1 noncontaminated shellfish sample, 1 naturally contaminated shellfish sample, and 2 shellfish samples spiked, respectively, at low (152.8 μg STX/100 g meat) and moderate (334.7 μg STX/100 g meat) levels. All samples were analyzed in duplicate. Mean recoveries were 35.1% for the low level and 46.6% for the moderate level. Relative standard deviations (RSD) for within-laboratory variations (repeatability) ranged from 5.4 to 9.8%; RSD for between-laboratory variations (reproducibility) varied from 7.8 to 39.6%, depending on STX level. On the basis of overall performance, all 8 participating laboratories were proficient in their use of the AOAC mouse bioassay.

scholarly journals Online Determination of Trace Amounts of Tannic Acid in Colored Tannery Wastewaters by Automatic Reference Flow Injection Analysis

2010 ◽  
Vol 2010 ◽  
pp. 1-4 ◽  
Author(s):  
Liang Wei
Keyword(s):  
Tannic Acid ◽  
Flow Injection ◽  
Flow Injection Analysis ◽  
Alkaline Solutions ◽  
Experimental Conditions ◽  
Reference Flow ◽  
Relative Standard ◽  
Standard Solution ◽  
Acid Reduction

A simple, rapid and sensitive method was proposed for online determination of tannic acid in colored tannery wastewater by automatic reference flow injection analysis. Based on the tannic acid reduction phosphotungstic acid to form blue compound in pH 12.38 alkaline solutions, the shade of blue compound is in a linear relation to the content of tannic acid at the point of the maximum absorption peak of 760 nm. The optimal experimental conditions had been obtained. The linear range of the proposed method was between 200 μgL−1to 80 mgL−1and the detection limit was 0.58 μgL−1. The relative standard deviation was 3.08% and 2.43% for 500 μgL−1and 40 mgL−1of tannic acid standard solution, respectively, (n=10). The method had been successfully applied to determination of tannic acid in colored tannery wastewaters and the analytical results were satisfactory.

Online Determination of Anionic Surfactant in Environmental Water

2012 ◽  
Vol 610-613 ◽  
pp. 1113-1116
Author(s):  
Liang Wei ◽  
Yi Chun Dai
Keyword(s):  
Anionic Surfactant ◽  
Sodium Dodecyl ◽  
Environmental Water ◽  
Buffer Solution ◽  
Experimental Conditions ◽  
Ethyl Violet ◽  
Relative Standard ◽  
Potassium Hydrogen ◽  
Standard Solution

It was found that ethyl violet can react with sodium dodecyl benzene sulfate (SDBS) to form ion associates in pH 2.2 ~ 2.8 of buffer solution of potassium hydrogen phthalate and hydrochloric acid in the presence of polyvinyl alcohol. Based on this, a method was proposed for online determination of anionic surfactant in environmental waterby. Under the optimum experimental conditions, Beers law was obeyed in the concentration range of 80 µg/L ~ 3500 µg/L of anionic surfactant (SDBS). The relative standard deviation of 2.1% was was obtained by injecting 800 µg/L of sodium dodecyl benzene sulfate standard solution (n=10). The detection limit calculated from three times of the average background noise was 4.39 µg/L. The proposed method had been applied successfully to the determination of anionic surfactant in environmental water and the results showed good agreement with that of the standard method.

Online Monitoring of Trace Copper (II) in Environmental Waters

2012 ◽  
Vol 599 ◽  
pp. 188-191
Author(s):  
Liang Wei ◽  
Yi Chun Dai
Keyword(s):  
Online Monitoring ◽  
Atomic Absorption Spectrophotometry ◽  
Neutral Red ◽  
Environmental Waters ◽  
Experimental Conditions ◽  
Standard Curve ◽  
Relative Standard ◽  
Standard Solution ◽  
Catalytic Spectrophotometry

Based on the fact that copper can catalyze the fading reaction of neutral red reduced by hydrogen peroxide using the alanine as a sensitizer in NH4Cl-NH3•H2O medium (pH 8.0), a method was developed for online monitoring of trace copper in environmental waters by flow injection catalytic spectrophotometry. The experimental conditions were optimized. Under optimum conditions, the linear range of the proposed method was between 1.0 µg/L to 125 µg/L and the correlation coefficient of standard curve was 0.9995. The detection limit of the proposed method was 0.11 µg/L. The relative standard deviation of 2.7% and 1.5% was obtained by injecting 15.00 µg/L and 100.00 µg/L copper of standard solution respectively (n=8). The proposed method had been applied to determination of trace amounts of copper in environmental waters. The results were in good agreement with those obtained by atomic absorption spectrophotometry (AAS)

Gas-Liquid Chromatographic Determination of Fluchloralin in Formulations

1977 ◽  
Vol 60 (5) ◽  
pp. 1145-1147
Author(s):  
Gregory S Grimes
Keyword(s):  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Reference Standard ◽  
Relative Standard ◽  
Liquid Chromatographic Determination ◽  
Standard Solution ◽  
Liquid Chromatographic

Abstract A gas-liquid chromatographic (GLC) method has been developed that is precise, rapid, simple, and specific for fluchloralin in emulsifiable liquid formulation. Sample and reference standard are weighed, internal standard solution is added, and an aliquot of the mixture is injected onto the chromatographic column. Fluchloralin gives a sharp symmetrical peak at about 5.4 min. The internal standard has a broader symmetrical peak at about 6.9 min. The relative standard deviation for 21 consecutive injections of the standard solution was 0.3773%. The method was compared with the official GLC method, 6.210–6.215, for the structurally similar trifluralin. Fluchloralin gave a sharp symmetrical peak at about 8.5 min; the internal standard had a sharp symmetrical peak at about 9.2 min. The relative standard deviation of 21 consecutive injections of reference standard solution was 0.6988%. Comparison of the variances of the 2 methods by the F-test at the 99% confidence level showed that the proposed method demonstrated substantially better precision.

scholarly journals Physicochemical Parameters of Real Wastewater Originating from a Plant Protection Products Factory and Modification of the QuEChERS Method for Determination of Captan

Molecules ◽  
2019 ◽  
Vol 24 (12) ◽  
pp. 2203 ◽  
Author(s):  
Ewa Szpyrka ◽  
Maciej Thomas ◽  
Magdalena Podbielska
Keyword(s):  
Matrix Effects ◽  
Solid Phase ◽  
Plant Protection ◽  
Oxygen Demand ◽  
Plant Protection Products ◽  
Electron Capture Detection ◽  
Quechers Method ◽  
Relative Standard ◽  
Real Wastewater

The aim of this study was the modification and application of the QuEChERS method for the preparation and purification of samples in order to determine the level of captan in real wastewater originating from a plant protection products factory which was characterized by a significant content of organic substances [Chemical Oxygen Demand (COD) = 856 ± 128 mg O2/L and Total Organic Carbon (TOC) = 62 ± 9 mg/L]. The optimization of the method consisted of the selection of solvents used for the extraction of captan from wastewater and also sorbents used to purify the extracts by the dispersion of a solid phase extraction technique (dSPE). Two steps were used: extraction and clean-up. In the extraction step, acetonitrile was replaced by anacetonitrile:acetone mixture. In the clean-up step by the dSPE, five sorbents were tested: Florisil®, aluminum oxide (Al2O3), zirconium oxide (ZrO2), silicon oxide (SiO2) and PSA (primary and secondary amine). Concentrations of captan in wastewater extracts were determined by gas chromatography (GC) combined with electron capture detection (μECD). The best recovery parameters and precision of the method were obtained for samples purified using ZrO2 (recovery 98% and precision expressed as relative standard deviation RSD 8%) and Florisil® (recovery 96%, RSD 9%). Limits of detection (LOD) and quantification (LOQ) for determination of captan in diluted extract of wastewater were 0.003 and 0.01 mg/L, respectively. Matrix effects were in the range of −69% to −44% for samples purified by ZrO2 and Florisil®, respectively. The modified and optimized method was applied for fast and simple determination of captan levels in real industrial wastewater samples, in which the concentration of captan in diluted extract was determined to be 4.0 ± 0.3 mg/L.

scholarly journals Quantitative Analysis of Lorazepam in Pharmaceutical Formulation Through FTIR Spectroscopy

2012 ◽  
Vol 9 (4) ◽  
pp. 2232-2238 ◽  
Author(s):  
Elaheh Konoz ◽  
Amir Hossein Mohsen Sarrafi ◽  
Marjaneh Samadizadeh ◽  
Samaneh Boreiri
Keyword(s):  
Limit Of Detection ◽  
Direct Determination ◽  
Good Alternative ◽  
Peak Height ◽  
Pharmaceutical Products ◽  
Height Measurement ◽  
Line Extraction ◽  
Relative Standard ◽  
Standard Solution

A Fourier transform infrared (FTIR) spectrophotometric method was development for the rapid, direct measurement of lorazepam in different pharmaceutical products. The method involves the off-line extraction of lorazepam with sonication and direct determination in the extract through peak height measurement in the 1704 cm-1using a baseline correction between 1850 and 1550 cm-1. For standardization an external calibration line established from standard solutions of lorazepam in chloroform were used. The method provides a limit of detection of 0.0030 mg per tablet (n=5), a relative standard deviation (RSD) of 2.65% for 5 independent measurement of standard solution at a concentration level of 1 mgg-1. Result obtained by FTIR agrees with those obtained by a reference methodology based on ultraviolet spectrometry and thus the developed procedure offers a good alternative for the determination of lorazepam in commercial products.

scholarly journals Online Preconcentration and Determination of Trace Amounts of Zinc in Nature Waters

2008 ◽  
Vol 2008 ◽  
pp. 1-5 ◽  
Author(s):  
Liang Wei ◽  
Xinshen Zhang ◽  
Yichun Dai ◽  
Jin Huang ◽  
Yong-hong Xie ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Tween 80 ◽  
Reaction Conditions ◽  
Experimental Conditions ◽  
Buffer Solutions ◽  
Relative Standard ◽  
On Line ◽  
Standard Solution ◽  
Zinc Determination

A simple, sensitive, reliable and flexible flow injection spectrophotometric method is proposed for on-line preconcentration and determination of trace amounts of zinc in water. At the presence of Tween-80 in pH 9.3 buffer solutions, the shade of color of Zn (II)-PAN complex is in a linear relation to the zinc amount at the point of the maximum absorption peak of 560 nm. The optimal experimental conditions, including reaction conditions and preconcentration conditions, had been obtained. The linear range of the proposed method was between 2.0 and 360 μg L−1and the detection limit was 0.42 μg L−1. The relative standard deviation was 3.55% and 2.14% for 5.0 μg L−1and 50 μg L−1of zinc standard solution (n=8). The method had been successfully applied to zinc determination in water samples and the analytical results were satisfactory.

scholarly journals QUANTITATIVE ANALYSIS OF ACETAMINOPHEN AND IBUPROFEN MIXTURE IN TABLET UTILIZING CENTERED AVERAGE ON SPECTRUM RATIO BY SPECTROPHOTOMETRIC TECHNIQUE

2018 ◽  
Vol 11 (12) ◽  
pp. 344 ◽  
Author(s):  
Muchlisyam Bachri ◽  
Tuty R P ◽  
Edward R
Keyword(s):  
Absorption Spectrum ◽  
Quantitative Analysis ◽  
Standard Deviation ◽  
Phosphate Buffer ◽  
Regression Equations ◽  
Relative Standard ◽  
Coefficient Corrélation ◽  
Standard Solution ◽  
Spectrum Ratio

Objectives: Centered average on spectrum ratio by spectrophotometric technique has been done validated for acetaminophen (ACT) and ibuprofen (IBU) in mixture. The goal of this research is to analyze concurrent determination of ACT and IBU mixture in tablet, using pH 7.2 phosphate buffer and ethanol (91:9) as solvent mixture.Methods: The spectrophotometric technique was made by addition of standard solution from IBU, and the absorption spectrum of each drug has been recorded, which is divided by corresponding concentration as a dividing factor; after that, the centered flat of ratio spectra of ACT and IBU concentrations was determined by calibration graphs with measuring at obtained maximum wavelengths 244 nm for ACT and 221 nm for IBU.Results: The research results showed that linearly correlation acetominophen and IBU are 3.0–9.0 μg/mL and 5.0–13.0 μg/mL, respectively, and linearly regression equations are 1.5800X+0.4809 and 0.0991X+0.0205 with coefficient correlation are 0.9962 and 0.9990. Result of ACT and IBU in local tablet is 100.72±0.12% and 98.82±0.06% with the average of percentage recovery for ACT and IBU is 100.01% and 100.31%, and relative standard deviation value is 0.03% and 0.06% respectively.Conclusion: It can be concluded that centered average on spectrum ratio spectrophotometric technique is a smooth, accelerated, correct, and rigid for the analysis of ACT and IBU in mixture.

scholarly journals A Novel Potentiometric Sensor for Determination of Neurotoxinβ-N-Oxalyl-L-α,β-Diaminopropionic Acid

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Omer Isildak ◽  
Furkan Saymaz ◽  
Ahmet Karadag ◽  
Nesrin Okumus Korkmaz ◽  
Azade Attar
Keyword(s):  
Response Time ◽  
Dynamic Range ◽  
High Sensitivity ◽  
Potentiometric Sensor ◽  
Membrane Sensor ◽  
Relative Standard ◽  
Selective Membrane ◽  
Continuous Work ◽  
Diaminopropionic Acid

A novel potentiometric sensor based on ionophore (Cd(NH2CH2CH2OCH2CH2OCH2CH2NH2)Ag3(CN)5) for the determination ofβ-N-oxalyl-l-α,β-diaminopropionic acid (ODAP) is developed. The ODAP-selective membrane sensor demonstrates high sensitivity and short response time. The detection limit of the ODAP-selective membrane sensor is about2×10-6 mol L-1and the response time is shorter than 6 s. The linear dynamic range of the ODAP-selective membrane sensor is between ODAP concentrations of1.0×10-2and1×10-6 mol L-1. The ODAP-selective membrane sensor exhibits good operational stability for at least one week in dry conditions at 4–6°C. It has a reproducible and stable response during continuous work for at least 10 h with a relative standard deviation of 0.28% (n= 18).

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