CIL Continues Development of Toxaphene Congener Standards

Commercial toxaphene, known by a variety of trade names, is a technical mixture of several hundred chlorinated camphenes. It is an extremely effective pesticide and was used extensively when DDT was banned from use. However, because of the complexity of the technical mixture analysis has been difficult, and the dearth of pure, high-quality individual standards has hindered development of robust analytical methods. Until recently, no 13C-toxaphene congeners were available, preventing analysts from enjoying the benefits of isotope dilution mass spectrometry (IDMS).

After finding initial success replacing DDT in many agricultural applications, within a few years toxaphene too was banned for most uses in much of the world. In 2001, toxaphene was included in the first round of chemical pollutants covered by the Stockholm Treaty, one of the “dirty dozen.”  For more information on toxaphene and the Stockholm Convention, click here: Stockholm Convention “Dirty Dozen” POPs.
 
As with the analysis of other complex mixtures such as PCBs (aroclors; kanechlors) and BDEs (commercial pentaBDEs and octaBDEs), most analysts have focused on methods that target key congeners. In PCB analyses, most laboratories target the WHO “dioxin-like” PCBs and/or the predominant or “marker” congeners. Since toxicity data is still being developed for BDEs, BDE analysis tends toward those predominant congeners found in relatively high levels in the technical products. While toxaphene analysis is still waiting for a definitive method, researchers tend to focus on the most bioaccumulative congeners such as Parlar 26, 50, and 62.

 With that in mind, CIL completed the arduous synthesis of uniformly ¹³C-labeled camphene, which was then selectively chlorinated, and target congeners were isolated. Unlabeled standards have been produced under the rigorous Certified Standard protocols developed by CIL for unlabeled PCB and BDE standards, and these were used to certify the ¹³C-labeled analogues. Currently, CIL offers seven unlabeled and seven ¹³C-labeled individual congeners and is producing more as customer demand warrants. 

CLM-7930-1.2 Parlar 26 (13C10) ULM-7828-1.2 Parlar 26 (unlabeled) CLM-8705-1.2 Parlar 32 (13C10) ULM-8665-1.2 Parlar 32 (unlabeled) CLM-8719-1.2 Parlar 39 (13C10) ULM-8767-1.2 Parlar 39 (unlabeled) CLM-7931-1.2 Parlar 50 (13C10) ULM-7829-1.2 Parlar 50 (unlabeled) CLM-7932-1.2 Parlar 62 (13C10) ULM-7830-1.2 Parlar 62 (unlabeled) CLM-8720-1.2 Parlar 69 (13C10) ULM-8768-1.2 Parlar 69 (unlabeled) CLM-8721-1.2 Parlar 70 (13C10) ULM-8769-1.2 Parlar 70 (unlabeled)