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 Anderson
1
, Eduardo de Jesus Oliveira
1
, Kyle Wojciechowski
2
1- Laboratorio de Tecnologia Farmaceutica, Federal University of Paraiba; 2- State University of New York at Oswego, NY, USA
Introduction Objectives
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. The method was to develop a High Pressure Liquid Chromatography (HPLC) method to quantify cocaine in Crack Cocaine samples that were seized by the State Police force of Paraiba
Methods
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.
Results
Run 2
120 120 120
Run 1 Run 3
100 100 100 80 80 80 60 60 60 40 y = 4E-05x + 2,7663 R² = 0,9978 40 y = 4E-05x + 1,21 R² = 0,9997 40 y = 4E-05x + 0,2524 R² = 0,9996 20 20 20 0 0 500000 1000000
Area
1500000 2000000 2500000 0 0 500000 1000000 1500000
Area
2000000 2500000 3000000 0 0 500000 1000000 1500000
Area
2000000 2500000 3000000 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. Figure 2. This is an example of an HPLC Crack sample readout with the Cocaine peaking at around 6.3 minutes
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.
% Purity Between Runs 1 and 2 vs 3
90,00 80,00 70,00 60,00 50,00 40,00 30,00 20,00 10,00 0,00 0,00 y = 0,8183x + 5,455 R² = 0,7908 10,00 20,00 30,00 40,00 50,00
% Purity of Run 3
60,00 70,00 80,00 90,00 100,00 Figure 3. This is a comparison of the % purity between Runs 1-2 and Run 3 for all of the samples.
References
Figure 4. This is a spreadsheet for the average purity, 6 for each, with the standard deviation for all 47 samples of Crack-Cocaine.
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 .