Monitoring of hydrolysis products of mustard gas, some sesqui- and oxy-mustards and other chemical warfare agents in a plant material by HPLC-MS/MS

At present, there is a real threat of chemical warfare agents being used in terrorist acts and military clashes. Sulfur and nitrogen mustards are blister agents with high lethality and rapid disruption of armed forces. These highly poisonous substances are hydrolyzed to the characteristic marker compounds when released into the environment. Analysis of environmental objects allows to establish the fact of alleged use of chemical warfare agents and to reveal their type. However, water and soil samples are not always reliable for retrospective analysis. The resulting chemical warfare agent markers may be washed out from the application site over time by groundwaters or atmospheric condensations. This study shows the potential for using plants as a convenient material for retrospective analysis. Garden cress (Lepidium sativum) was chosen as a model plant for this purpose, since it can be easily and quickly grown hydroponically. The plants were cultivated in the environment of the selected markers to study an accumulation of these compounds by the plants. An effective and fast method of homogenization with subsequent ultrasonic extraction was applied. The extracts were analyzed using a specially developed and validated HPLC-MS/MS approach. Separation of the hydrophilic markers was carried out on a reversed-phase column with a polar endcapping. Sensitive mass spectrometric detection was performed in the multiple reaction monitoring mode. Achieved limits of detection for most markers were in the range of 2-40 ng mL(-1). It was discovered from the research that after the removal of markers from the growing medium the plants are able to store and concentrate these markers for at least 5 weeks, ensuring a high retrospectivity of the analysis. The obtained results indicate the perspective of using plants as additional objects of analysis during the investigation of incidents related to the use of chemical warfare agents. However, more complex plants and models should be studied in the future.