Defence Research & Development Establishment

This investigation delves into the development of cupric oxide functionalized activated carbon fabrics (ACF@CuO) as a filter material for self-decontaminating protective clothing designed to counter chem. warfare agents (CWAs).Three variants of samples were developed by controlling functionalization levels (7.5%, 13.0%, 16.0% weight/weight) through optimized precursor concentrations, integrating CuO particles onto ACF surfaces.Comprehensive anal. using techniques like FTIR, BET surface area, SEM, EDX, STEM, XRD, TGA, and XPS explored the material′s properties.The studies concentrated on evaluating the performance through kinetic studies of self-detoxification of CWA Sarin (GB) using developed ACF@CuO materials analyzed by Gas Chromatog.-Mass Spectrometry (GC-MS).ACF@CuO with 16% weight/weight functionalization exhibited superior self-decontamination against GB, achieving 92.87% efficiency within 18 h, in contrast to 26.55% for ACF alone.Addnl., materials were tested for tensile strength, air-permeability, and Sulfur Mustard breakthrough time (HDBTT) as per IS 17377:2020 standardThe material with 13% weight/weight functionalization emerged as the recommended filter layer for CWA protective clothing designed for defense and civilian safety applications.The significant improvements in the self-decontamination efficiency of the material were attributed to the synergistic effects of ACF′s adsorption capabilities combined with the decontamination properties of CuO rod-shaped crystals embedded in the surface of ACF.

The present study explores the potential of silica solid phase extraction for gas chromatography mass spectrometric analyses of A- and V-series nerve agents. Owing to the presence of basic amidine and amine moieties, these analyte undergo strong ionic interactions with inherently acidic silica surfaces, producing poor recoveries. Subtle optimizations in the elution composition empowered the analytes to overcome the retention barriers from sorbent surfaces. Acetone containing 10 % (v/v) NH₄OH effectively minimized strong analyte-sorbent interactions allowing good to excellent recoveries. Recoveries for A-series agents ranged from 88 to 96 %. VX, which is reported to be poorly recoverable from such sorbent matrices offered best data so far, reaching up to 74 % under optimized conditions. The method detection limits for the selected analytes in mass spectrometric analysis ranged from 47 to 171 ng/ml. Strong affinities of analytes towards silica sorbent were further exploited to expand the scope of analysis and establish the method's efficacy for a wide range of organic matrices. The applicability of the method to the real world applications was also validated in blind spiking exercises in diverse organic liquid samples received in 48th, 50th and 52nd proficiency tests conducted by the Organization for the Prohibition of Chemical Weapons (OPCW).

Ricin is a potential biowarfare agent. It is a phytotoxin isolated from castor seeds. At present there is no antidote available for ricin poisoning, patients only get supportive treatment based on their symptoms. This highlights the importance of early detection to avoid severity of accidents and reduce the risk factor. Considering this, our study aimed to develop a highly sensitive and specific sandwich ELISA for the detection of ricin.

Ricin was purified from castor seeds. Anti-ricin polyclonal and monoclonal antibodies were generated from rabbit antisera and hybridoma cell (1H6F1) supernatant using a protein A/G column. Antibody titer estimation was done using Indirect ELISA. A streptavidin-biotin-based sandwich ELISA was developed and the limit of detection (LOD), linear range, intra and inter-assay coefficient of variation (CV), and cross-reactivity with other similar toxins were determined. Interference of human plasma samples spiked with ricin was also checked.

The LOD of the ELISA was found to be 0.45 ng/ml, with a linear range of 0.90-62 ng/ml, intra and inter-assay CV ranged from 3.34 % to 5 % and 5.17 % to 10.80 % respectively. The assay was not cross-reactive with other similar ribosome-inactivating protein (RIP) toxins. Ricin was detected in spiked plasma samples.

The developed assay is highly sensitive and specific for detecting ricin and is not cross-reactive with other similar types of toxins. The assay can detect ricin in spiked plasma samples, so it has the potential to be used for the analysis of clinical samples after ricin poisoning.