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Direct Analysis using Paper-Spray Mass Spectrometry: Method Development for the Rapid Screening of Drugs of Abuse for Forensic Toxicology
e (QuantIon Technologies, Inc., IN)
ray ion source, mechanism for
ssette indicating sample deposition
aying into mass spectrometer inlet.
Results
Quantitative - Single drug
• Amitriptyline spiked in bovine blood and evaluated at various concentrations using
FIGURE 4. TraceFinder 3.0 softwa
targeted screening analysis mode
identified by exact m/z values and
presence of two fragments from t
in the table below because acquir
amitriptyline-
d
3
as the internal standard.
• Amitriptyline-spiked in MeOH/water (data not shown) and blood (10–5,000 ng/mL)
yielded limits of quantitation (LOQ) of 10 ng/mL for drug in solvent and LOQ of 25
ng/mL for samples in blood.
• Variability in terms of %RSD (Std Dev/Mean*100) is between <1 to 13% for drug out
maximum peak width supported b
of solvent. Figure 2 displays amitriptyline data for dried blood spots.
Screening for drugs of abuse: resolving power, accurate mass for compound
identification
Fi
3 h th t hi h d lt hi h l i
(70 000 d 140 000 FWHM
• gure s ows a g an u ra g reso v ng powers
,
an
,
at
m/z
200) are required when evaluating samples from complex matrices with no
sample preparation and no prior chromatographic separation.
• Results from TraceFinder, which can be used for targeted or unknown screening
analysis, are neatly summarized in Figure 4. All six drugs are positively identified from
d bl
d t
l
a ry oo spo samp e.
‘All Ion Fragmentation’ and isotopic pattern matching for compound confirmation
• Accurate mass m/z values were used for identification of screened drugs. Isotopic
pattern matching and two fragments from the AIF experiment were used for drug
confirmation (TraceFinder table Fig. 4).
• Figure 5 shows accurate mass fragmentation spectra by AIF for a DBS sample
containing a mixture of 6 drugs.
• Fragments unique for a particular drug can be identified, examples shown for codeine
and cocaine.
FIGURE 2b. Quantitative results for
amitriptyline normalized by internal
t d d f
DBS l
C lib ti
• Other fragments are shared by a few of the drugs present, for example amphetamine
and methamphetamine, whose structures differ only by a methyl group.
• Mass Frontier™ 7.0 software was used to generate potential fragments for each drug
using the “Generate Fragments and Mechanisms“ tool which were then compared to
the MS spectra
FIGURE 5. Accurate mass fragmen
Fragmentation’ experiment provide
drugs. Sample is a mixture of six d
s an ar rom
samp es. a ra on
curve and %RSD variability (n=3) shown.
.
Screening for drugs of abuse at various concentrations
• A drug mixture of six compounds was analyzed at 100, 500, 1000 and 2500 ng/mL for
forensic toxicology screening. Amphetamine, methamphetamine, cocaine,
unique fragments and two that are
C
C d i
/
93 0340
Amitriptyline
Y= -0.0519284+0.001756*X R^2=0.9933 W:1/X
9
FIGURE 3. The use of higher resolving power,
e.g.
, 70,000 and 140,000 (FWHM at
cocaethylene, codeine and PCP are shown in this work.
• This group of samples were detected by full MS down to 100 ng/mL levels (Figure 6).
F:
FTMS + p ESI Full
70
80
90
100
ce
oc
o e ne,
m z
.
F:
FTMS+ pESIFullms21000.00@hcd43.00 [50.00-32 ...
70
80
90
100
e
93.0706
93.0583
2
3
4
5
6
7
8
m/z
200), is required for the identification of drugs from DBS due to matrix
interference in MS experiment. Bovine blood spiked with six drugs, four drugs
shown below. Resolving power from 17,500, 35,000, 70,000 and 140,000 top to
bottom. The [M+H]
+
ion is highlighted by red line.
Level (ng/mL)
% RSD
amphetamine
PCP
codeine
cocaethylene
20
30
40
50
60
Relative Abundan
181.0087
20
30
40
50
60
Relative Abundanc
93.0340
OH
0
1000
2000
3000
4000
5000
ng/mL
0
1
244.2284
244.2069
244 2071
300.1592
300.2911
300.2190
300 1614
318.1711
318.1964
318.1391
318.2667
318 1716
nce
0
20
40
60
80
100 136.0738
136.1130
136 0738
17,500
RP
181
0
10
93.00
93.05
93.10
93.15
m/z
0
10
93.0109
.
244.2269
244.2068
.
300.1810
300.2907
300.2186
300.1606
300 1433
.
318.1916
318.1432
318.2648
318.1715
80
100
0
20
40
60
80
100
Relative Abunda
.
136.1127
136.1055
136.1127
35,000
Common fragment for ampheta
codeine methamphetamine PC
244.2268
244.2066
300.2912
300.1794
.
300.1608
318.1414 318.2840
318.2286
318.1711
60
80
100
0
20
40
60 136.0739
136.1057
136.1127
136.0739
70,000
140 000
,
,
* No replicates available
244.15 244.20 244.25
m/z
244.2269
300.1 300.2 300.3
m/z
300.2910
300.2185
300.1431
300.3274
318.1 318.2 318.3
m/z
318.1417318.1907318.2836
136.10
m/z
0
20
40
136.1056
136.0845
,
