Environmental Engineering Reference
In-Depth Information
HCN, reaction of CN
−
in HCN with 2,3-naphthalenedialdehyde and taurine,
and luorimetric measurement (l
excitation
= 418 nm; l
emission
= 460 nm) of the
reaction product, 1-cyano-2-benzoisoindole (1-cyano[
f
]benzoisoindole; CBI)
derivative (Felscher and Wulfmeyer
1998
).
6. High-performance liquid chromatography by using isotopic potassium cyanide
(K
13
C
15
N) as an internal standard, microdiffusion of CN
−
and
13
C
14
N
−
from blood
as HCN and H
13
C
14
N, reaction of CN
−
and
13
C
14
N
−
in HCN and H
13
C
14
N with
2,3-naphthalenedialdehyde and taurine to produce nonisotopic and isotopic ana-
logs of CBI, and qualitative and quantitative determination of both CBI analogs
by high performance liquid chromatography-mass spectrometric detection
(Tracqui et al.
2002
).
Signs and symptoms for exposures to CO and HCN, in relation to their respective
concentrations as %COHb and blood CN
−
, are tabulated in previous publications
(Chaturvedi
2009, 2010a
; Gossel and Bricker
1994b
; ISO International Standard
2008
).
Fifteen nonire aviation accidents, involving 17 fatalities (15 pilots and 2 pas-
sengers), were reported during 1991-1998 (Chaturvedi et al.
2001
). The levels of
COHb in these fatalities ranged from 10 to 69%; CN
−
was not detected. The selec-
tive presence of COHb in the absence of CN
−
and ire in these accidents was hypoth-
esized to result from the inhalation of CO present in the interior, because of the
faulty exhaust/heating systems. The source of such CO is incomplete oxidation of
aviation fuel. The factors that contributed to these 15 accidents were heating/exhaust
system malfunctions, pilot error, and/or CO-induced incapacitation. Of these fac-
tors, three accidents, accounting for ive fatalities (COHb levels of the ive: 12, 24,
41, 43, and 69%), were attributed to CO-induced incapacitation or a defective
exhaust system. Of the total fatal accidents (2,837) that occurred during the 8-year
period, nonire, CO-related accidents amounted to only 0.53%.
Elevated COHb levels were reported in 13 of the 2,449 pilots killed in general
aviation operations between 1973 and 1977, possibly from faulty heaters or exhaust
systems (Laceield et al.
1978
). Many accidents reported in 1981 that involved tur-
boprop aircraft potentially resulted from incapacitation of pilots who had inhaled
toxic fumes introduced through the cabin pressurization system (Sanders
2007
). In
response to these accidents, the thermal (300-600°C) decomposition products from
aircraft petroleum-based engine and synthetic lubricating oils were evaluated for
time-to-incapacitation and time-to-death in rats; the animals were exposed to smoke
from these products (Crane et al.
1983
). The decomposition of these oils produced
CO in suficient quantities to produce the toxic responses noted.
The bleed air that is diverted from a location just forward of the jet engine com-
bustion chamber has a temperature of approximately 500°C. Thermal breakdown
products of jet engine lubrication oils have not been fully characterized at this tem-
perature. Thus, the temperature stability of two commercially available jet oils was
investigated by van Netten and Leung (
2000
), who analyzed for the release of vari-
ous volatiles and gases by gas chromatography-mass spectrometry. The results show
that >100 ppm CO and some CO
2
were generated after exposing the oils to a tem-
perature of 525°C. Nitrogen dioxide and HCN were not detected. The presence of
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