Stability of diethylene glycol in human tissue: analysis of a physic-chemical factor in isolation step.

GIANNUZZI L., FERRANTI A. AND FERRARI L.

Hamamatsu

Congreso; 50 th Meeting The International Association of Forense Toxicolgy (TIAFT2012), Hamamatsu; 2012

50 th Meeting The International Association of Forense Toxicolgy (TIAFT)

Introduction: The stability of drugs in human tissue is an important issue in forensic toxicology. Generally data for classic drugs have already been reviewed. However, some toxic agents, as diethylene glycol (DEG), have been no enough studied and it does avoid the correct interpretation of toxicological finding. There are several issues to be taking account, as physics-chemical property of moiety, biological samples, time elapsed between intoxication and death, death and analysis, isolation methods, between others. In previous paper we have analyzed in details our finding about an Argentinean outbreak occurred in 1992, with data about clinical and forensic finding. Aims: The purpose of our work was analyzed and discussed the DEG behavior in isolation step, in methanolic extract and the probable retention from complex lipids. Also we compared with other agents such as microorganisms Pseudomonas sp. Methods: The tissue samples (blood, liver and kidney) were obtained from 15 victims. Blood were obtained by puncturing the femoral vein and analyzed 24 hs after. 50 g of liver and kidney were taken from victims and stored frozen until analysis. We isolated DEG from tissue with methanol through continue extraction by soxhlet and analyzed by GC-FID according to Ferrari & Giannuzzi procedure (1), lipids from methanolic extract were analyzed by TLC-FID (Iatroscan Equipment) with MP: toluene-chloroform-formic acid (75:25:2) and petrolatum ether-Toluene (70:30) and SP: silicagel GF Results: We saw in 7 out of 15 a case that if methanolic extract is stored at 2°C or below a semicristalline fraction is formed and give a negative result in GC-FID analysis. Conversely, if extract remain in an ambient temperature, the crystalline fraction is not formed and so DEG is detected by GC-FID. We found that the crystalline fraction contains: 57.4% of free fatty acid (mostly palmitic, estearic and oleic acid), 37.3 % phospholipids (fosfatidiletanol y esfingomielina) and 5.3% cholesterol. So, it?s possible to state a DEG retention mechanism owing to the formation of mesomorphic phase. Furthermore, the high quantities of phospholipids in the fraction could retain DEG by polar interaction forming at de same time a solid solution with fat acid free. Conclusions: These circumstances could explain that several cases of acute DEG intoxication, in our Argentinean episode and also in several cases of Panamanian episode give negative result in analyzed tissue. On the other hand, should be taking into account that Pseudomonas sp, could transform DEG in other polar moieties. We will discuss this issue.