- ------------
DETector Engineering
&
Technology, inc.
486N.Wiget Lane,Walnut Creek, CA94598USA
telephone: (925) 937-4203
fax: (925) 937-7581
DEI
e-mail:
innovations in chemical detection
Different Methods of Acquiring Non-Volatile Sample Residues on aCeramic Rod
for Subsequent Selective Screening by the RTIA Method
RTIAlNPD -various pesticide sensitivities
chlorpyrifos
ceramic rod dipped into
100
ppm
alldataat
10240pAfullscale
solutions ofeacl1 pesticide, solvent
evaporated atroom temperature,
rod and residue into 275 degCRTIA
malathion
imidan
diazinon
endosulfan
J
,
1L
carbaryl
airpump
=
300mUmin
hydrogen
=
6mUmin
reactor
=
275 degC
linuron
imidan
T1D·2 ionsource
heat
=
3.040A
polarization
=.
5V
lJ~
Tip of 1/16 inch diameter ceramic rod dipped
into solution of non-volatile pesticides in a
volatile solvent like Methanol. Solvent
evaporated, then rod inserted into RTIA
reactor for detection of selected vapors with
a Nitrogen-Phosphorus Detector. RTIAlNPD
detected Nand P pesticide residues, but not
Endosulfanwhich contained lots ofCI and no
N or P. An NPD is commonly used as a GC
detector, and .these data illustrate its use in
detecting Linuron and Carbaryl which
normallyarenot analyzedusingaGCmethod.
RTIA -NPD (TID-2
ion source)
non-volatile cigarette smoke residue
sample -1minuteexposureofceramic rod to
smoke, rod then inserted into275 degCreactor
rod 1
rod 2
51200 pA
fullscale
1min.
10240 pA
~aleJJ
methanol
2ndwipewith
wipe
acetone
sample - insidesurfaceofglass bell jarwipedwith
moistened chemwipeafter5minuteexposureof
bell jarinterior tosmoke fromasmoldering
cigarette, bell jarwipe transferred toceramic rod
whichwas then inserted intoRTIA reactor
'------ ------"Third Hand Smoke". RTIAINPO detection of
non-volatile residues deposited on surfaces
exposed to Second Hand Smoke. Top data
illustrate signals from smoke residues
deposited directly onto tips
0
f 2 ceramic
rods. Bottom data illustrate Methanol and
Acetone wipes of a surface exposed to
Second Hand Smoke, with the wipes
subsequently transferred to the tip of a
ceramic rod. For surfaces that can tolerate it,
Acetone is a more effective wipe than
Methanol for removing non-volatile residues.
Website :
E-mail :
TelNo : 03 9762 29034 . . . inAUSTRALIA
