行政院國家科學委員會專題研究計畫果報告:福馬林固定器官之法醫毒物學研究
Date Issued
1999
Date
1999
Author(s)
郭宗禮
DOI
882314B002189
Abstract
Parathion, o,o-diethyl-o-p-nitrophenyl
phosphrothionate, is a volatile organophosphorous
pesticide. The fatal intoxication
by parathion is mostly the result of oral
ingestion for the purpose of suicide. On
the other hand, accidental inhalation and
topical exposures to parathion during the
formulation or the spray of this pesticide by
worker or farmer are the common routes of
entry for systemic effects.
It has been known that parathion
undergoes P450-dependent oxidative desulfuration,
metabolizing to paraoxon
which potentially inhibited acetylcholinesterase
and resulted in muscarinic and
nicotinic symptoms. The main metabolite
of parathion was p-nitrophenyl-glucuronide
(pNP) making up 85% of the urinary
excretion, about 6% was excreted as pnitrophenyl-
sulfate and only 1% as free
pNP Although the severity of intoxication
and the time of survival correlated well
with the dose of parathion, the potency of
paraoxon to inhibit AChE fails to predict
the acute toxicity class..
A novel method for the determination
of pNP in formalin-fexed tissures of
suspected patient with parathion
intoxication has been developed. The
method is based on the hydrolysis of
conjugated pNP with concentrated sulfuric
acid. P-nitrophenol was extracted with
toluene-ether mixtures, then back extracted
into 2N NH4OH. After reacting with
phenol and reducing with TiCl3, the
indophenol blue was measured by 1storder
derivative spectrophotometry.
The results showed that the
linearity of the standard curves
measured 1st.-order derivative spectrophotometry
were excellant in the range
of 0.2-5.0 μ g/mL (r2 = 0.9999 ).
Recoveries of 89% were obtained from
the spiked formalin-fixed rat liver by
1st-order spectrophotometry. On the
other hand, the digestion efficiencies of
formalin-fixed tissures with sulfuric
acid were better than those of
microwave. The assay, which has a
limit of detection of 0.03 μ g/mL, is
accurate, reproducible and much more
sensitive than traditional spectrophotometry.
It has been applied to determine
pNP in the formalin-fixed tissues of
victim with suspected parathion
poisoning. It was found that the
concentrations of pNP in formalin-fixed
liver and kidney were 2.2 and 67.4
μg/mL, respectively. It revealed that this
proposed method could be used for the
purposes of forensic toxicology.
Subjects
Pesticide
Parathion
Formalinfixed tissues
Derivative spectrophotometry
Quantification
SDGs
Publisher
臺北市：國立臺灣大學醫學院法醫學科
Type
journal article
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