Interlaboratory comparison to evaluate a standardized calibration procedure for the headspace analysis of aromatic solvents in blood

Isomeric separation and quantitation of di-(2-ethylhexyl) trimellitates and mono-(2-ethylhexyl) trimellitates in blood by LC-MS/MS

A new and fast HPLC-method for the simultaneous determination of tri-(2-ethylhexyl) trimellitate (TOTM or TEHTM), its diesters 2,4-di-(2-ethylhexyl) trimellitate (2,4-DEHTM), 1,4-di-(2-ethylhexyl) trimellitate (1,4-DEHTM), 1,2-di-(2-ethylhexyl) trimellitate (1,2-DEHTM) and monoesters 1-mono-(2-ethylhexyl) trimellitate (1-MEHTM), 2-mono-(2-ethylhexyl) trimellitate (2-MEHTM) and 4-mono-(2-ethylhexyl) trimellitate (4-MEHTM) together with di-(2-ethylhexyl) phthalate (DEHP) and its primary metabolite mono-(2-ethylhexyl) phthalate (MEHP) in blood was developed and validated. The analytes are extracted from blood using liquid-liquid extraction and are chromatographically separated by reversed-phase HPLC using core shell material. Quantitative assessment was performed by ESI-tandem mass spectrometry in negative ionization mode using stable isotope dilution. In less than 30min six postulated primary metabolites of TOTM along with the DEHP metabolite MEHP can be selectively and sensitively quantified. Additionally, the method enables the determination of the parent plasticizers TOTM and DEHP. The detection limits in blood were found to range between 0.7-5.5μg/L for all TOTM analytes. Precision and repeatability of the method were proven by relative standard deviations between 0.9% and 8.7%. TOTM, an alternative plasticizer to DEHP, is already increasingly used for medical devices. Nevertheless, data about the human metabolism of TOTM are still limited. The presented method is the first one enabling the simultaneous determination of the parent plasticizers TOTM and DEHP together with their primary degradation products (DEHTM, MEHTM, MEHP) and can thus be applied manifold including the investigation of the human metabolism of TOTM.

Toxicological aspects of preparedness and aftercare for chemical-incidents

The threat of using chemical warfare agents still exists despite the 1993 Chemical Weapons Convention. Preparedness for attacks with chemical agents has become an important issue of national security programs. It can be anticipated that toxicologists will be increasingly involved in preparedness programs of their institutions and of the government, no matter whether they work in agencies, industry or universities. Toxicologists must get prepared to give fast and reliable advice in the case of an attack, a sabotage or an accident with release of toxic chemicals. They should be familiar with the principles of hazard management and with incident command structures and cooperate with first responders of other organizations involved such as fire department and medical emergency teams already in the planning phase. In the emergency planning phase, toxicologists are expected to help identifying possible hazards. Moreover, they consult public health services with regard to toxicosurveillance and advice hospitals regarding antidotes, decontamination procedures and shelters. They may be involved in the procurement of antidotes and of protective equipment and will support qualified analytical laboratories. In the response phase, toxicologists must be ready to gain and to interpret analytical data, to support the medical care of poisoned victims and to provide repeated risk assessment reports. This requires an on-scene access to databases and registries. The aftercare phase includes the identification of exposed persons, mapping of contaminated areas, organization of decontamination measures and the release of areas. A medical study may be initiated to observe long-term health effects. Good cooperation between regulatory and clinical toxicologists, specific education of toxicologist in the field of chemical emergencies and regular trainings are essential elements of good preparedness.