scholarly journals A New Colorimetric Assay for Determination of Selected Toxic Vapors and Liquids Permeation Through Barrier Materials Using the Minitest Device

2017 ◽  
Vol 54 (4) ◽  
pp. 748-751 ◽  
Author(s):  
Pavel Otrisal ◽  
Stanislav Florus ◽  
Lubomir Svorc ◽  
Ghita Barsan ◽  
Danut Mosteanu
Keyword(s):  
Chemical Resistance ◽  
Sulfur Mustard ◽  
Colorimetric Assay ◽  
Barrier Material ◽  
Toxic Compound ◽  
Practical Applications ◽  
Barrier Materials ◽  
Liquid Phases ◽  
Static Conditions

A moment of permeation of both gaseous and liquid phases of a toxic compound through a barrier material has been indicated colorimetrically at the same time on 20 exposed places using suitable colour indicators. The newly developed device MINITEST is able to evaluate the resistivity of both porous and non-porous barrier materials of a textile character against permeation of toxic vapours (permeation) and liquids (penetration) in static conditions. As a model test chemical either the sulfur mustard or significantly alkaline or acid volatile toxic compound have been applied. During the permeation, these species react with a suitable acid-base indicator and a markedly coloured stain can be created. Newly developed MINITEST device enables determination of chemical resistance of areal barrier materials not only in a process of their development but also in the rate of their practical applications.

scholarly journals Ratiometric Colorimetric Detection of Nitrite Realized by Stringing Nanozyme Catalysis and Diazotization Together

Biosensors ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 280
Author(s):  
Mengzhu Wang ◽  
Peng Liu ◽  
Hengjia Zhu ◽  
Bangxiang Liu ◽  
Xiangheng Niu
Keyword(s):  
Detection Limit ◽  
Signal Analysis ◽  
High Efficiency ◽  
Colorimetric Assay ◽  
Low Cost ◽  
Colorimetric Detection ◽  
Health It ◽  
Practical Applications ◽  
Higher Sensitivity

Due to the great threat posed by excessive nitrite in food and drinking water to human health, it calls for developing reliable, convenient, and low-cost methods for nitrite detection. Herein, we string nanozyme catalysis and diazotization together and develop a ratiometric colorimetric approach for sensing nitrite in food. First, hollow MnFeO (a mixture of Mn and Fe oxides with different oxidation states) derived from a Mn-Fe Prussian blue analogue is explored as an oxidase mimic with high efficiency in catalyzing the colorless 3,3′,5,5′-tetramethylbenzidine (TMB) oxidation to blue TMBox, presenting a notable signal at 652 nm. Then, nitrite is able to trigger the diazotization of the product TMBox, not only decreasing the signal at 652 nm but also producing a new signal at 445 nm. Thus, the analyte-induced reverse changes of the two signals enable us to establish a ratiometric colorimetric assay for nitrite analysis. According to the above strategy, facile determination of nitrite in the range of 3.3–133.3 μM with good specificity was realized, providing a detection limit down to 0.2 μM. Compared with conventional single-signal analysis, our dual-signal ratiometric colorimetric mode was demonstrated to offer higher sensitivity, a lower detection limit, and better anti-interference ability against external detection environments. Practical applications of the approach in examining nitrite in food matrices were also verified.

The Most Significant Influences of Decontamination Mixtures Containing Chlorinating and Oxidizing Agents on Barrier Materials Formed by Isobutylene-Isoprene Rubber

2018 ◽  
Vol 55 (3) ◽  
pp. 325-331 ◽  
Author(s):  
Pavel Otrisal ◽  
Zdenek Melicharik ◽  
Lubomir Svorc ◽  
Romana Oancea ◽  
Vlad Barsan
Keyword(s):  
Sulfur Mustard ◽  
Armed Forces ◽  
Chemical Warfare Agent ◽  
Chemical Warfare ◽  
Breakthrough Time ◽  
Barrier Material ◽  
The Czech Republic ◽  
Rescue Service ◽  
Barrier Materials ◽  
Isoprene Rubber

The influences of hypochlorite DM with oil ingredient and without it, which is introduced into the armament not only by the Czech Armed Forces Chemical Corps, but also by the chemical services specialists of the Czech Republic Fire Rescue Service, on a substrate consisting of a barrier material based on isobutylene-isoprene rubber (butyl rubber) were presented in this paper. Based on the repeated exposure of the substrate formed by the barrier layer material selected by this decontamination mixture and its subsequent rinsing, a change of the breakthrough time has been studied using the MIKROTEST method employing the chemical warfare agent of sulfur mustard and Congo red as a detecting agent.

scholarly journals Testing Methods of Assessment for the Chemical Resistance of Insulating Materials Against the Effect of Selected Acids

2018 ◽  
Vol 55 (4) ◽  
pp. 545-551 ◽  
Author(s):  
Pavel Otrisal ◽  
Zdenek Melicharik ◽  
Lubomir Svorc ◽  
Simona Bungau ◽  
Ioan Virca ◽  
...  
Keyword(s):  
Chemical Resistance ◽  
Real Data ◽  
Armed Forces ◽  
Weapons Of Mass Destruction ◽  
Military Operations ◽  
Mass Destruction ◽  
The Czech Republic ◽  
Barrier Materials ◽  
Chemical Resistivity

The Czech Armed Forces' soldiers of all specializations and mainly the chemical corps'specialist are prepared for task fulfillment in military and non-military operations within those a real threat of weapons of mass destruction employment and, occasionally, the real danger of toxic industrial materials leakage is present. They can solve problems caused by acids leakage in contaminated areas mainly during task fulfillment in non-military operations on the Czech Republic territory in cooperation with Fire Rescue Brigades' chemical specialists. Individual protective equipment which is established in the Czech Armed Forces were neither design for this purpose and, moreover, nor tested and thus there is no real data concerning their chemical resistivity. In recent time, some methods have been introduced into the Czech Armed Forces environment. They are useful for determination of chemical resistivity of barrier materials against toxic compounds detectable with acid-basic (colorimetric) methods and conductometric ones. The paper deals with the possibility of using the presented methods and compares the suitability of their application in relation to the protective garments designated for the Czech Armed Forces members' body surface.

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