Methods of incorporation of detection reagents for phosgene detection into nanocomposite pellets
|Year of publication
|MU Faculty or unit
|Introduction: Chemical warfare agents (CWAs) are fast-acting and lethal substances, even at low concentrations. They still pose a serious threat in some parts of the world. Rapid detection and identification are important parts of safety precautions. Detection by detection tubes (DTs), which can contain carriers in form of pellets, is based on the formation of colored products, which are usually evaluated visually. Methods: This study aimed to prepare pellets containing silica nanoparticles and other substances with high specific surface area using the spheronization extrusion technique and to verify the possibility of incorporating detection reagents (DRs) into pellets. Samples were dried in a hot air oven or lyophilized, and their physico-mechanical properties were evaluated. Selected samples were tested for diphosgene by Oritest s.r.o. The behavior of the samples in the presence of acetyl chloride, which is a simulant of phosgene, was also investigated. Results: Samples containing Neusilin® US2 had higher hardness, but samples containing FujiSil® had higher interparticular porosity. Open pores on the surface increased the specific surface area and enabled better adsorption of DRs and CWAs. Lyophilization resulted in a decrease in the number of closed pores and an increased number of open pores. The incorporation of DRs from an ethanol solution during wetting reduced pellet hardness. The physico-mechanical properties of all batches met the requirements for filling into DTs. Conclusion: During the detection of diphosgene, the pellets did not reach sufficient sensitivity. When tested with an acetyl chloride solution in acetone at a concentration of 1100 ng/ml, the tests were positive; however, at a concentration of 5.5 ng/ml, the pellets did not reach sufficient sensitivity. The used DRs or the methods of their incorporation are considered inappropriate. To improve their sensitivity, it would be advisable to increase the basicity of carriers, increase the amount of DRs, or use different DRs.