scholarly journals A Novel Amperometric Biosensor Based on Poly(allylamine hydrochloride) for Determination of Ethanol in Beverages

Sensors ◽  
2021 ◽  
Vol 21 (19) ◽  
pp. 6510
Author(s):  
Oana Maria Istrate ◽  
Lucian Rotariu ◽  
Camelia Bala
Keyword(s):  
Good Accuracy ◽  
Sol Gel ◽  
Storage Conditions ◽  
Applied Potential ◽  
Screen Printed Electrode ◽  
Response Range ◽  
New Type ◽  
Allylamine Hydrochloride ◽  
Working Parameters

Herein, we report on a new type of ethanol biosensor based on a screen-printed electrode modified with poly(allylamine hydrochloride). The alcohol dehydrogenase was immobilized on the surface of the sensor using the sol–gel matrix. Working parameters such as applied potential, pH, NAD+ concentration, storage conditions were optimized. A response range between 0.05 and 2 mM was found with a sensitivity of 13.45 ± 0.67 µA/mM·cm2 and a detection limit of 20 µM. The developed biosensor was used to detect ethanol in commercial beverages with good accuracy.

Selective Determination of Dopamine at Poly Sulfosalicylic Acid/Graphene Modified Electrode with Composite Properties of Biochemical Materials

2012 ◽  
Vol 600 ◽  
pp. 230-233 ◽  
Author(s):  
Qiu Huan Han ◽  
Jian Fei Xia ◽  
Zong Hua Wang ◽  
Yan Zhi Xia ◽  
Fei Fei Zhang
Keyword(s):  
Modified Electrode ◽  
Linear Response ◽  
Sulfosalicylic Acid ◽  
Selective Determination ◽  
Response Range ◽  
New Type ◽  
20 Nm ◽  
Composite Properties ◽  
Linear Response Range

A new type of poly (sulfosalicylic acid)/graphene modified electrode (PSA/GH/GCE) was fabricated by dispensing graphene (GH) on glassy carbon electrode (GCE) and then electro-polymerized sulfosalicylic acid onto GH/GCE with cyclic voltammtry method. It can be used with composite properties of biochemical materials for highly selective and sensitive detection of dopamine (DA) even in the presence of mass ascorbic acid (AA). The linear response range for DA was 70 nM to 700 μM, and the detection limit was 20 nM (S/N = 3).

Trial production of γ-type energy filtering TEM

1995 ◽  
Vol 53 ◽  
pp. 604-605
Author(s):  
Y. Taniguchi ◽  
E. Nakazawa ◽  
S. Taya
Keyword(s):  
Magnetic Energy ◽  
Electron Optics ◽  
Electron Microscopic ◽  
Mass Spectrometers ◽  
Ion Optics ◽  
Energy Filtering ◽  
New Information ◽  
New Type ◽  
Fringing Fields

Imaging energy filters can add new information to electron microscopic images with respect to energy-axis, so-called electron spectroscopic imaging (ESI). Recently, many good results have been reported using this imaging technique. ESI also allows high-contrast observation of unstained biological samples, becoming a trend of the field of morphology. We manufactured a new type of energy filter as a trial production. This energy filter consists of two magnets, and we call γ-filter since the trajectory of electrons shows ‘γ’-shape inside the filter. We evaluated the new energyγ-filter TEM with the γ-filter.Figure 1 shows schematic view of the electron optics of the γ-type energy filter. For the determination of the electron-optics of the γ-type energy filter, we used the TRIO (Third Order Ion Optics) program which has been developed for the design of high resolution mass spectrometers. The TRIO takes the extended fringing fields (EFF) into consideration. EFF makes it difficult to design magnetic energy filters with magnetic sector fields.

Optimization of sol-gel based fibre-optic cholinesterase biosensor for the determination of organophosphorus pesticides

2000 ◽  
Vol 42 (7-8) ◽  
pp. 283-290 ◽  
Author(s):  
H.-C. Tsai ◽  
R.-A. Doong
Keyword(s):  
Fiber Optic ◽  
Ph Value ◽  
Rapid Determination ◽  
Organophosphorus Pesticides ◽  
Sol Gel ◽  
Neutral Red ◽  
Fluorescent Indicators ◽  
Low Leakage ◽  
Fiber Optic System

A sol-gel based fiber-optic biosensor with acetylcholinesterase as the biorecognition element has been developed for the rapid determination of organophosphorus pesticides. Nine fluorescent indicators, acridine, acridine orange, neutral red, DAPI, rhodamine B, fluorescein, umbelliferone, FITC on celite and FITC-dextran, have been examined to optimize the fiber-optic system. Results showed that acridine and FITCs were sensitive to the change of pH value caused by the enzyme-substrate catalysis reaction. However, the sensitivity of acridine was 260 times lower than that of FITCs. Higher toxicity of acridine to acetylcholinesterase than FITC was also observed. Moreover, the high-molecular-weight FITC-dextran showed low leakage rate when immobilizing using sol-gel technology, showing that the FITC-dextran was a suitable pH sensitive fluorescent indicator for the OPPs biosensor. The response of the fiber-optic biosensor to the substrate, acetylcholine, was highly reproducible (RSD=3.5%). A good linearity of acetylcholine in the range from 0.5 to 20 mM was also obtained (R2=0.98). Furthermore, a 30% inhibition can be achieved in 30min when 152 ppb paraoxon was added into the system. The results show the possibility for real-time determination of organophosphorus pesticides by using the biosensor developed in this study.

Multi-walled Carbon Nanotubes Reinforced into Hollow Fiber by Chitosan Sol-gel for Solid/Liquid Phase Microextraction of NSAIDs from Urine Prior to HPLC-DAD Analysis

2019 ◽  
Vol 20 (5) ◽  
pp. 390-400 ◽  
Author(s):  
Nabil N. AL-Hashimi ◽  
Amjad H. El-Sheikh ◽  
Rania F. Qawariq ◽  
Majed H. Shtaiwi ◽  
Rowan AlEjielat
Keyword(s):  
Carbon Nanotubes ◽  
Liquid Phase ◽  
Hollow Fiber ◽  
Sol Gel ◽  
Liquid Phase Microextraction ◽  
Extraction Device ◽  
Multi Walled Carbon Nanotubes ◽  
Solid Liquid ◽  
Walled Carbon Nanotubes

Background: The efficient analytical method for the analysis of nonsteroidal antiinflammatory drugs (NSAIDs) in a biological fluid is important for determining the toxicological aspects of such long-term used therapies. Methods: In the present work, multi-walled carbon nanotubes reinforced into a hollow fiber by chitosan sol-gel assisted-solid/ liquid phase microextraction (MWCNTs-HF-CA-SPME) method followed by the high-performance liquid chromatography-diode array detection (HPLC–DAD) was developed for the determination of three NSAIDs, ketoprofen, diclofenac, and ibuprofen in human urine samples. MWCNTs with various dimensions were characterized by various analytical techniques. The extraction device was prepared by immobilizing the MWCNTs in the pores of 2.5 cm microtube via chitosan sol-gel assisted technology while the lumen of the microtube was filled with few microliters of 1-octanol with two ends sealed. The extraction device was operated by direct immersion in the sample solution. Results: The main factors influencing the extraction efficiency of the selected NSAIDs have been examined. The method showed good linearity R2 ≥ 0.997 with RSDs from 1.1 to 12.3%. The limits of detection (LODs) were 2.633, 2.035 and 2.386 µg L-1, for ketoprofen, diclofenac, and ibuprofen, respectively. The developed method demonstrated a satisfactory result for the determination of selected drugs in patient urine samples and comparable results against reference methods. Conclusion: The method is simple, sensitive and can be considered as an alternative for clinical laboratory analysis of selected drugs.

A new type of incubation apparatus for the determination of metabolically produced 14CO2

1966 ◽  
Vol 14 (2) ◽  
pp. 290-295 ◽  
Author(s):  
Marco Baggiolini ◽  
Marcel H. Bickel
Keyword(s):  
New Type

scholarly journals Selectivity of Tungsten Oxide Synthesized by Sol-Gel Method Towards Some Volatile Organic Compounds and Gaseous Materials in a Broad Range of Temperatures

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 523 ◽  
Author(s):  
Simonas Ramanavičius ◽  
Milda Petrulevičienė ◽  
Jurga Juodkazytė ◽  
Asta Grigucevičienė ◽  
Arūnas Ramanavičius
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Sol Gel ◽  
Temperature Dependent ◽  
Sensing Systems ◽  
Sensing Material ◽  
Operational Temperature ◽  
Volatile Organic ◽  
Different Gases

In this research, the investigation of sensing properties of non-stoichiometric WO3 (WO3−x) film towards some volatile organic compounds (VOC) (namely: Methanol, ethanol, isopropanol, acetone) and ammonia gas are reported. Sensors were tested at several temperatures within the interval ranging from a relatively low temperature of 60 up to 270 °C. Significant variation of selectivity, which depended on the operational temperature of sensor, was observed. Here, the reported WO3/WO3–x-based sensing material opens an avenue for the design of sensors with temperature-dependent sensitivity, which can be applied in the design of new gas- and/or VOC-sensing systems that are dedicated for the determination of particular gas- and/or VOC-based analyte concentration in the mixture of different gases and/or VOCs, using multivariate analysis of variance (MANOVA).

Effect of Different Storage Conditions on Soybean Oil Acid Value

2014 ◽  
Vol 962-965 ◽  
pp. 1235-1238
Author(s):  
Mei Mei Hao ◽  
Xi Hong Li ◽  
Hai Dong Liu ◽  
Wei Qiao Yang ◽  
Chong Xiao Shao ◽  
...  
Keyword(s):  
Moisture Content ◽  
Soybean Oil ◽  
Acid Value ◽  
Storage Condition ◽  
Storage Conditions

Under the condition of nine kinds of storage, In this thesis, through the determination of acid value of soybean oil, to search for the best storage condition, used to prevent the soybean oil acid value rise, through the analysis of the acid value data, We find the best storage condition, is 0°C, 6% moisture content, and PVC plastic wrap packaging.

scholarly journals Optimising storage conditions and processing of sheep urine for nitrogen cycle and gaseous emission measurements from urine patches

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alice F. Charteris ◽  
Karina A. Marsden ◽  
Jess R. Evans ◽  
Harry A. Barrat ◽  
Nadine Loick ◽  
...  
Keyword(s):  
Freeze Drying ◽  
Storage Conditions ◽  
Chemical Components ◽  
Gaseous Emissions ◽  
Gaseous Emission ◽  
Grazing Systems ◽  
And Storage ◽  
Sheep Urine ◽  
Country Specific

AbstractIn grazing systems, urine patches deposited by livestock are hotspots of nutrient cycling and the most important source of nitrous oxide (N2O) emissions. Studies of the effects of urine deposition, including, for example, the determination of country-specific N2O emission factors, require natural urine for use in experiments and face challenges obtaining urine of the same composition, but of differing concentrations. Yet, few studies have explored the importance of storage conditions and processing of ruminant urine for use in subsequent gaseous emission experiments. We conducted three experiments with sheep urine to determine optimal storage conditions and whether partial freeze-drying could be used to concentrate the urine, while maintaining the constituent profile and the subsequent urine-derived gaseous emission response once applied to soil. We concluded that filtering of urine prior to storage, and storage at − 20 °C best maintains the nitrogen-containing constituent profile of sheep urine samples. In addition, based on the 14 urine chemical components determined in this study, partial lyophilisation of sheep urine to a concentrate represents a suitable approach to maintain the constituent profile at a higher overall concentration and does not alter sheep urine-derived soil gaseous emissions.

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