Reactivation fluoride

Recently, Noort et al developed a procedure that is based on straightforward isolation of adducted BuChE from plasma by means of affinity chromatography with a procainamide column, followed by pepsin digestion and LC/electrospray tandem MS analysis of a specific nonapeptide containing the phosphonylated active site serine-198 residue (5). This method surpasses the limitations of the fluoride-reactivation method, since it can also deal with dealkylated ( aged ) phosphonylated BuChE. The method allowed the positive analysis of several serum samples of Japanese victims of the terrorist attack in the Tokyo subway in 1995. Furthermore, the method could be applied for detection of ChE modifications induced by, e.g., diethyl paraoxon and pyridostigmine bromide, illustrating the broad scope of this approach. This new approach... 

Blood Fluoride reactivation method Phospho-rylated BuChE (+ other proteins) GC-MS GC-HR-MS With large volume injection Phosphonofluo- ridates i.s. deuterated OP or plasma exposed to deuterated OP Easily accessible internal standards and reference compounds LOD 10 pg/ml (0.05-0.1% BuChE inhibition) Not applicable to all OP s... 

Figure 9. Fluoride reactivation of organophosphate-inhibited butyrylcholinesterase. (Reprinted from Toxicology and Applied Pharmacology, Vol. 184, D. Noort, H.P. Benschop and R.M. Black, Biomonitoring of Exposure to Chemical Warfare Agents A Review, pages 116-126 (2002), with permission from Elsevier Science.)...

Application of the fluoride-reactivation method to serum samples of victims from the Tokyo subway attack, and of the Matsumoto incident, yielded, sarin concentrations in the range of 0.2-4.1ng/ml serum (44). Evidently, these casualties had been exposed to an organophosphate with the formula i-PrO(CH3)P(0)X, presumably with X = F (sarin). 

Adams, T.K., Capacio, B.R., Smith, J.R., Whalley, C.E., Korte, W.D. (2004). The application of the fluoride reactivation process to the detection of sarin and soman nerve agent exposure in biological samples. Drug Chem. Toxicol. 27 77-91. 

Tabim Blood Adduct to BuChE Fluoride reactivation GC-NPD, FPD, MS Van der Schans et al. (2004a)... 

A major drawback of the fluoride reactivation method is that not all nerve agent adducts are amenable to fluoride reactivation, with the aged adduct of soman the best known example. This problem can be solved by looking at the BuChE enzyme itself Fidder et al (2002) published a method based on the LC-MS analysis of a nerve agent phosphylated nonapeptide derived after pepsin digestion of inhibited butyrylcholinesterase. The authors presented a procedure to extract BuChE from plasma using... 

Barr, J.R. (2004). Improvements of the fluoride reactivation method for the verification of nerve agent exposure. J. Anal. Toxicol. 28(5) 364-71. 

B. Fluoride Reactivation Followed by Gas Chromatography-Mass Spectrometry... 

Van der Schans, M.J., Noort, D., Fidder, A., Degenhardt, C.E.A.M., Benschop, H.P., Langenberg, J.P. (2002). Retrospective detection of exposure to organophosphorus anticholinesterases fluoride reactivation and mass spectrometric analysis of phosphylated human butyrylcholinesterase. The meeting of NATO TG 004 Task Group on Prophylaxis and Therapy of Chemical Agents. November 4-7, 2002, Oslo, Norway. 

Adams TK, Capacio BR, Smith JR, Whalley CE, Korte WD. The application of the fluoride reactivation... 

Sarin from BuChE/serum 0.2-4.1 ng/ml (12/18) Fluoride reactivation used (Polhuijs et al, 1997)... 

Application of fluoride reactivation to serum samples of casualties of the Matsumoto and Tokyo incidents yielded sarin concentrations in the range 0.2 1.1 ng/ml serum (Polhuijs et al, 1997). Hydrolytic displacement of the phospho-nyl residue identified /PrMPA at levels sufficient for full-scan mass spectra to be obtained from samples collected from casualties who died (Nagao et al, 1997) MPA was also identified. MPA was detected in formalin-fixed brain tissues some two years later using a similar procedure (Matsuda et al, 1998). The phosphonylated peptic nonapeptide from BuChE was identified in serum samples from several casualties of the subway attack (Fidder et al, 2002). 

In this case, the two dienophile functional groups in 33 remained unreacted due to the presence of the bulky triisopropylsilyl (TIPS) protecting groups [191]. Removal of the latter with ammonium fluoride reactivated the ethynyl dienophiles for the next-generation synthesis by another round of addition of the AB2 systems. The shape and packing density of the dendrimers could be tuned by the choice of the ethynylated core and of the branching reagent (e.g., the AB4 system 33a... 

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