scholarly journals Kinerja Elektroda Platina Terlapis Enzim Butirilkholinesterase-Selulosa Asetat-Glutaraldehida untuk Deteksi Diazinon

KOVALEN ◽  
2020 ◽  
Vol 6 (2) ◽  
pp. 106-111
Author(s):  
Thamrin Azis ◽  
Nurhaeni ◽  
Caterina Bijang ◽  
A. Nurwahida
Keyword(s):  
Detection Limit ◽  
Response Time ◽  
Electrochemical Sensor ◽  
Cellulose Acetate ◽  
Pesticide Residues ◽  
Electrochemical Biosensor ◽  
Measurement Range ◽  
Test Results ◽  
Limit Value ◽  
Electrode Composition

Diazinon (o, o-diethyl-o [2-isopropyl-6-methyl pyrimidynyl] phosphorotioate) is one of the organophosphate group pesticides widely used to protect cabbage plants (Brassica olarecea). Pesticide residues left in plants can bind to the cholinesterase enzyme and cause system disruption nerve. Analysis of diazinon residues in cabbage plants needs to be done to determine the level of toxicity caused. The electrochemical biosensor method as an electrochemical sensor uses a working electrode of platinum wire coated with the enzyme butybholchesteresterase (BChE) and cellulose acetate (SA) membrane and glutaraldehyde (GA) can be used for the analysis of pesticide residues. The test results of the SA electrode composition of the 10% GA 20% membrane obtained Nernst factor prices 28.1 µV / decade with a measurement range of 10-9 - 10-6 M, detection limit value of 1.29 x 10-7 M response time of  30 - 300 seconds. Keywords: biosensor, butylochholesterase, membrane, electrochemistry

scholarly journals THE PREPARATION OF AN IODATE SELECTIVE ELECTRODE USING SILVER IODATE AS THE ACTIVE AGENT IN A CHITOSAN SUPPORT

2010 ◽  
Vol 7 (3) ◽  
pp. 284-287
Author(s):  
Ani Mulyasuryani ◽  
Qonitah Fardiyah ◽  
Rizki Sugiri
Keyword(s):  
Detection Limit ◽  
Response Time ◽  
Active Agent ◽  
Reference Electrode ◽  
Chitosan Solution ◽  
Precipitation Reaction ◽  
Selective Electrode ◽  
Cell Potential ◽  
Chitosan Membrane ◽  
Electrode Cell

The iodate-selective electrode based on the principle of precipitation reaction could be made by coating the platinum wire with silver iodate (AgIO3). In this research was carried out optimization the iodate-selective electrode using chitosan membrane as an AgIO3 support. The AgIO3 were added in the 2 mL 1% chitosan solution, is 0.5 to 2.5 % (w/v). The thickness of the membrane used is 6 to 12 µm. The electrode cell potential is measured against Ag/AgCl electrode as a reference electrode. The optimum electrode performance was at 2.0 % of AgIO3 with thickness a membrane of 10 µm. The iodate-selective electrode has a Nernstian factor is 52.96 mV/decade and a response time of 10 seconds. The concentration range was determined from 10-3 M to 10-1 M and the detection limit is 1.12 x 10-5 M.   Keywords:  Ion Selective Electrode, Iodate, Chitosan Membrane

scholarly journals Design of multilayer microfluidic paper chip and its visual detection of pesticide residues

2020 ◽  
Vol 11 ◽  
pp. 170-182
Author(s):  
Li zhi Li ◽  
Han Ping Mao
Keyword(s):  
Pesticide Residues ◽  
Visual Detection ◽  
Channel Structure ◽  
Test Results ◽  
Mixed Effect ◽  
Detection Range ◽  
Long Time ◽  
Paper Chip ◽  
Channel Structures ◽  
High Repeatability

With the increase of China's grain production, the use of pesticides is gradually increasing. Traditional pesticide detection takes a long time and requires expensive experimental instruments, which is not conducive to the rapid and accurate detection of pesticide residues in the field. To solve this problem, this paper proposes a visual detection method of pesticide residues based on multi-layer microfluidic paper chips. The internal channel structure of paper chip is designed from the perspective of efficient mixing. Through the simulation of the mixed effect of three kinds of staggered channel structures, which are arc type, triangle type, and ladder type, the "ladder-type h-0.3, s-2.6" is selected as the best-staggered structure, and the mixing strength is 0.91534. The best simulation structure was tested by a colored reagent, and the image processing of 15 test results was carried out with MATLAB. The average mixing strength was 0.84, and the and the standard deviation was 0.022. The visual detection experiment of acetamiprid and profenofos in cabbage samples was carried out by using the device，The detection range of acetamiprid was 4~72 μg/kg, and the detection range of profenofos was 3~54 μg/kg . The recovery of acetamiprid was 75%~85%, and the recovery of profenofos was 80%~90%. The detection range and recovery rate indicate that the device has high repeatability and accuracy in the actual sample detection

Significance of Abuse Chemical Contamination of Returnable Dairy Containers: Hazard Assessment

1978 ◽  
Vol 41 (12) ◽  
pp. 965-973 ◽  
Author(s):  
JOHN M. GASAWAY
Keyword(s):  
Hazard Assessment ◽  
Pesticide Residues ◽  
Daily Intake ◽  
World Health ◽  
Test Results ◽  
Chemical Contamination ◽  
Laboratory Findings ◽  
Laboratory Test Results ◽  
Health Organization ◽  
Water Contents

Certain pesticide residues reabsorbed into milk (or water) contents when stored in LEXAN® resin and polyethylene plastic returnable milk containers that had been exposed to diluted pesticide products, washed, and subsequently filled. The significance of these laboratory test results is comprehensively discussed by attempting to characterize the nature of exposure to pesticide residues from a washed returnable dairy container, as opposed to exposure to milk containing pesticide residues of non-container origin. Laboratory findings are compared to actual public use experience with returnable plastic dairy containers. A hazard assessment is presented, which includes a comparison of quantities of pesticide residues found extracting with existing Federal milk tolerance standards, food tolerance standards, unavoidable contaminant food additive regulations, World Health Organization and Safe Drinking Water Committee acceptable daily intake values. The probability of purchase of milk that is contaminated with pesticide residues, where the washed returnable dairy container is the source, is presented.

A Novel Electrochemical Sensor for the Analysis of Salbutamol in Pork Samples by Using NiFe2O4 Nanoparticles Modified Glassy Carbon Electrode

2013 ◽  
Vol 850-851 ◽  
pp. 1279-1282 ◽  
Author(s):  
Su Xing Luo ◽  
Yuan Hui Wu ◽  
Hua Gou ◽  
Yan Liu
Keyword(s):  
Detection Limit ◽  
Electrochemical Sensor ◽  
Glassy Carbon Electrode ◽  
Glassy Carbon ◽  
Electrochemical Method ◽  
Carbon Electrode ◽  
Modified Glassy Carbon Electrode ◽  
Peak Current ◽  
Anodic Peak Current ◽  
Pork Samples

In this work, a simple and sensitive electrochemical method sensor was developed to determine salbutamol based on magnetic NiFe2O4nanoparticles modified glassy carbon electrode. It was found the anodic peak current of salbutamol was linear with the concentration of salbutamol from 2.0 μM to 60 μM with a detection limit of 1.0 μM (S/N=3). The developed method was successfully applied to determine salbutamol content in pork samples with satisfactory results.

A comparative study of electrocatalytic oxidation of glucose on conductive Ni-MOF nanosheet arrays with different ligands

2020 ◽  
Vol 44 (41) ◽  
pp. 17849-17853
Author(s):  
Yanxia Qiao ◽  
Rui Zhang ◽  
Fangyuan He ◽  
Wenli Hu ◽  
Xiaowei Cao ◽  
...  
Keyword(s):  
Detection Limit ◽  
Comparative Study ◽  
Response Time ◽  
Electrocatalytic Oxidation ◽  
Glucose Sensor ◽  
High Sensitivity ◽  
Fast Response ◽  
Serum Samples ◽  
Nanosheet Arrays ◽  
Oxidation Of Glucose

A glucose sensor based on conductive Ni-MOF nanosheet arrays/CC exhibits a fast response time, a low detection limit, a high sensitivity, and it can also be applied for the detection of glucose in human serum samples.

scholarly journals The migration of pesticide residues in groundwater at a bank filtration site (Krajkowo well field, Poland)

2019 ◽  
Vol 78 (20) ◽  
Author(s):  
Krzysztof Dragon ◽  
Dariusz Drozdzynski ◽  
Jozef Gorski ◽  
Roksana Kruc
Keyword(s):  
Detection Limit ◽  
Pesticide Residues ◽  
Horizontal Well ◽  
Total Concentration ◽  
Bank Filtration ◽  
Vertical Wells ◽  
River Bank ◽  
Well Field ◽  
River Bottom ◽  
River Bank Filtration

Abstract River bank filtration systems are widely used for water supply purposes. Using these systems, the movement of water over short distances between the river bottom and extraction wells can decrease the concentrations of some contaminants. Such systems are especially important for the removal of specific micro-pollutants that seasonally appear in river water. In this article, pesticides migration at the Krajkowo well field is analysed based on different water extraction schemes. The water is extracted by two groups of wells (one located 60–80 m from the Warta River, and the second located more than 400 m from the river) and by a horizontal well with radial drains located 5 m below the river bottom. Based on this scheme, the rate of pesticide residues removal was analysed in wells located at different distances from the river channel. The results of the three sampling campaigns conducted in summer and autumn 2017 and winter 2018 indicate the presence of pesticide compounds in the Warta River (max. total concentration of 0.171 μg/l). The pesticides were also present in the horizontal well (max. total concentration of 0.137 μg/l). Much smaller concentrations (max. 0.064 μg/l) were observed in vertical wells located 60–80 m from the river. Additionally, in the well located 250 m from the river, only two pesticide constituents were detected (at concentrations just above the detection limit), and in a well located 680 m from the river, the concentrations of pesticide residues were below the detection limit (excluding isoproturon, which was slightly above the detection limit). This research illustrates the effectiveness of pesticides removal by river bank filtration.

Highly sensitive potentiometric sensors for thorium ions detection using morpholine derivative self-assembled on silver nanoparticles

RSC Advances ◽  
2016 ◽  
Vol 6 (81) ◽  
pp. 77854-77862 ◽  
Author(s):  
Zeinab F. Akl ◽  
Tamer Awad Ali
Keyword(s):  
Silver Nanoparticles ◽  
Detection Limit ◽  
Response Time ◽  
Water Samples ◽  
High Selectivity ◽  
Fast Response ◽  
Potentiometric Sensors ◽  
Fast Response Time ◽  
Highly Sensitive ◽  
Morpholine Derivative

Potentiometric screen-printed electrodes were constructed for Th(iv) determination in water samples. The optimized electrodes exhibited fast response time, wide linear range, low detection limit and high selectivity towards Th(iv) ions.

Tailor-made peptide sensor for detection of matrix metalloproteinase 2 in blood serum

2015 ◽  
Vol 7 (13) ◽  
pp. 5371-5374 ◽  
Author(s):  
Huifeng Xu ◽  
Hongzhi Ye ◽  
Lishuang Yu ◽  
Yuwu Chi ◽  
Xianxiang Liu ◽  
...  
Keyword(s):  
Detection Limit ◽  
Matrix Metalloproteinase ◽  
Blood Serum ◽  
Electrochemical Sensor ◽  
Matrix Metalloproteinase 2

We designed a simple and sensitive peptide electrochemical sensor for detection of MMP-2, with a detection limit of 0.3 ng mL−1.

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