Transcript Purity Identification of Crack-Cocaine Through the Use of

We selected 47 samples of crack seized by police and they were weighed by difference and diluted in 100% acetonitrile in the first two races and 80% acetonitrile in water in the third race.
The method used a high-efficiency liquid chromatography with diode array detector (Thermo Scentific, USA). The mobile phase was an aqueous solution of 0.01% triethylamine (solvent A) and acetonitrile (solvent B). The mobile phase (pH 7.8) was eluted in isocratic mode at 55% B (v/v) 1mL/min.
The separation was achieved using a chromatographic column C-18 (15cm x 4.6 mm id x 5mm, 5 Ace, catalog the ACE-121-1546). Calibration curves were constructed with 6 points between 3.45 μg/ml and 103.65 μg/ml. The detection was performed using a diode array detector and quantification of cocaine was made to 224nm. The column was maintained at 30 degrees celsius during every race.
The samples were diluted in 2 ml tubes eppendorffs with a solution of 40% acetonitrile in water and filtered through polyvinylidene fluoride membrane (0.45 μm) for HPLC vials. Aliquots (10ul) samples at a concentration of the 75 μg/ml were directly injected into the liquid chromatography by autosampler.
Purity Identificaion of Crack-Coccaine
Through the use of HPLC
Rony Anderson1, Eduardo de Jesus Oliveira1, Kyle Wojciechowski2
1- Laboratorio de Tecnologia Farmaceutica, Federal University of Paraiba; 2- State University of New York at Oswego, NY, USA
Objectives
Introduction
Crack-Cocaine is an illicit drug throughout
the world today. It is highly addictive and can be
used in a variety of ways which may include
injection into veins and smoking of the crack.
With Brazil now being the second largest
consumer of Crack-Cocaine in the world, certain
techniques have to be done to combat this drug
invasion. To do this, an efficient and accurate
method of drug analysis has to be done in order
to have a chance of combating the sale of the
drug and also to see how the drug is evolving.
Methods
The method was to develop a High
Pressure Liquid Chromatography (HPLC)
method to quantify cocaine in CrackCocaine samples that were seized by the
State Police force of Paraiba
We selected 47 samples of crack seized by police and they were
weighed by difference and diluted in 100% acetonitrile in the first two
races and 80% acetonitrile in water in the third race.
The method used a high-efficiency liquid chromatography with
diode array detector (Thermo Scentific, USA). The mobile phase was an
aqueous solution of 0.01% triethylamine (solvent A) and acetonitrile
(solvent B). The mobile phase (pH 7.8) was eluted in isocratic mode at
55% B (v/v) 1mL/min.
The separation was achieved using a chromatographic column C18 (15cm x 4.6 mm id x 5mm, 5 Ace, catalog the ACE-121-1546).
Calibration curves were constructed with 6 points between 3.45 μg/ml and
103.65 μg/ml. The detection was performed using a diode array detector
and quantification of cocaine was made to 224nm. The column was
maintained at 30 degrees celsius during every race.
The samples were diluted in 2 ml tubes eppendorffs with a
solution of 40% acetonitrile in water and filtered through polyvinylidene
fluoride membrane (0.45 μm) for HPLC vials. Aliquots (10ul) samples at a
concentration of the 75 μg/ml were directly injected into the liquid
chromatography by autosampler.
Results
120
Run 2
120
Run 3
100
100
100
80
80
80
60
Amount (ug/mL)
Amount (ug/mL)
Amount (ug/mL)
Run 1
120
60
40
40
y = 4E-05x + 2.7663
R² = 0.9978
40
y = 4E-05x + 1.21
R² = 0.9997
20
20
0
0
500000
1000000
1500000
2000000
0
Area
y = 4E-05x + 0.2524
R² = 0.9996
20
0
2500000
60
500000
1000000
1500000
Area
2000000
2500000
0
3000000
0
500000
1000000
1500000
2000000
2500000
3000000
Area
Figure 1. These are the correlation curves of the standard sample of Crack-Cocaine for three different runs in which the area of the unknown samples where based off of.
% Purity Between Runs 1 and 2 vs 3
90.00
80.00
70.00
% Purity of Runs 1 and 2
60.00
50.00
y = 0.8183x + 5.455
R² = 0.7908
40.00
30.00
20.00
10.00
0.00
0.00
10.00
20.00
30.00
40.00
50.00
60.00
70.00
80.00
90.00
100.00
% Purity of Run 3
Figure 2. This is an example of an HPLC Crack
sample readout with the Cocaine peaking at
around 6.3 minutes
Figure 3. This is a comparison of the % purity
between Runs 1-2 and Run 3 for all of the samples.
Conclusion
Overall, the results from the third run were
more accurate than that of the first and second
runs. This is due to the increased accuracy of
weighing techniques and pipeting techniques
over the time of first two runs. The next step
would be to do NMR tests on all of the samples
then compare the results with the HPLC results
to see the data agrees with each other.
Figure 4. This is a spreadsheet for the average purity, 6 for each,
with the standard deviation for all 47 samples of Crack-Cocaine.
References
Hays, PA, Thompson, RA (2009) The processing
method enabling the use of peak height
need for accurate and proton NMR quantitation.
Magnetic Resonance in Chemistry 47:
819-824
.
Acknowledgements