6
Quantitation of Seven Designer Cathinones in Urine Using Q Exactive Mass Spectrometer
Conclusion
We achieved our goal of a 0.5-ng/mL LOQ for the three newly-regulated cathinones,
MDPV, mephedrone and methylone, as well as methylone, ethylone and butylone in
urine. Naphyrone, which shows greater variability, can be detected down to 0.5 ng/mL
in a qualitative manner. Deuterated internal standards are essential for rigorous
quantitation of these compounds.
For Forensic Toxicology use only.
All trademarks are the property of Thermo Fisher Scientific and its subsidiaries.
This information is not intended to encourage use of these products in any manners that might infringe the
intellectual property rights of others.
FIGURE 8. Representative chromatogram of cathinones at 0.5 ng/mL in urine
reconstructed at 5 ppm mass accuracy.
FIGURE 9. Inter-assay QC results
L, it showed more variability than the
from lot to lot. Absolute recoveries for
relative recoveries using MDPV-d8 as
. All available internal standards were
A lack of a deuterated analog for
rrections and negatively effects method
considered qualitative.
butylone
ethylone
LQC
2.5 ng/mL
MQC
25 ng/mL
HQC
100 ng/mL
LQC
2.5 ng/mL
MQC
25 ng/mL
HQC
100 ng/mL
Mean
2.28
26.0
99.0
2.31
25.9
99.6
%Bias
-8.7
4.1
-1.0
-7.4
3.4
-0.4
%CV
3.7
3.8
4.4
3.4
3.0
1.7
MDPV
mephedrone
LQC
2.5 ng/mL
MQC
25 ng/mL
HQC
100 ng/mL
LQC
2.5 ng/mL
MQC
25 ng/mL
HQC
100 ng/mL
Mean
2.30
25.7
98.4
2.38
26.7
97.8
%Bias
-8.1
2.9
-1.5
-4.7
6.8
-2.2
%CV
5.8
6.3
5.1
7.1
1.9
2.7
methedrone
methylone
LQC
2.5 ng/mL
MQC
25 ng/mL
HQC
100 ng/mL
LQC
2.5 ng/mL
MQC
25 ng/mL
HQC
100 ng/mL
Mean
2.49
28.1
105
2.34
26.1
99.6
%Bias
-0.3
12.5
5.0
-6.5
4.6
-0.4
%CV
4.4
6.4
3.1
5.1
1.8
3.1
naphyrone
LQC
2.5 ng/mL
MQC
25 ng/mL
HQC
100 ng/mL
Mean
2.55
22.9
103
%Bias
2.1
-8.3
3.0
%CV
22
8.5
5.2
1.0
1.2
1.4
1.6
1.8
2.0
2.2
2.4
2.6
2.8
Time (min)
0
20
40
60
80
100
Relative Abundance
mephedrone
methedrone
methylone
butylone
ethylone
MDPV
naphyrone
0
1
2
3
4
5
6
7
8
9
10
0 200 400 600 800 1000
Area Ratio
ng/mL
methylone
R
2
= 0.9967
s of cathinones in urine.
0
1
2
3
4
5
6
7
8
9
10
0 200 400 600 800 1000
Area Ratio
ng/mL
ethylone
R
2
= 0.9926
0
1
2
3
4
5
6
7
8
9
10
0 200 400 600 800 1000
Area Ratio
ng/mL
mephedrone
R
2
= 0.9900
1...,210,211,212,213,214,215,216,217,218,219 221,222,223,224,225,226,227,228,229,230,...374