Newest approaches to quantitative assessment of bioactive organotins

Abstract

New approaches for assessing the toxicity of organotin chemical species have been developed. These approaches are based upon the selective responses of sensitive biodetectors whose chemical and molecular interactions with a wide variety of toxicants have been previously determined and reported. Bioassays capable of quantitating and chemically speciating toxicants for impacts on diverse bacterial sensors are discussed herein. The principal new development is a laser/bacterial bioassay which is capable of differentiating between various toxic chemicals and specifically distinguishing between the different organotin species based on their mechanism of toxic action. The system uses a battery of isogenic Bacillus subtilis strains genetically engineered to respond differentially to specific toxicants. The response is monitored by differential light scattering of a laser which is integrated with a computerized system that collects and analyzes the data. The system routinely generates fully analyzed data within 66 min for most samples. It is capable of making 1,200 measurements on each sample within 2 to 4 seconds, and shows promise as a rapid and inexpensive system to monitor organotins and various other toxicants on site.