|Cocaine - A Brief Overview|
|A History of the Study of Cocaine in Hair|
|The Controversy of Hair Testing|
|General Procedures of Hair Testing|
|Detailed Procedure to Extract Compounds|
|A Few Chemical Structures|
|>>>Go to Lab|
The Detailed Procedure Used to Extract Compounds
Approximately 40 mg of pre-wash hair was weighed out and treated with 1 mL of 0.1 M HCl. The solution was allowed to sit for 18 hours in a stoppered test tube at 50°C. The samples were heated using a Pierce Reacti-therm heating module.
The solution was neutralized with 0.1 M NaOH. 2 mL phosphate buffer, made from potassium phosphate salt, at pH 9.2, was added to the solution. The solution was extracted with chloroform/isopropanol/n-heptane (50:17:33 v/v) twice. After shaking and centrifugation, the test tube was put under a nitrogen stream to evaporate the organic phase.
The sample was derivatized using 100 microliters of heptafluorobutyric anhydride and 70 microliters hexafluoropropanol for 30 minutes at 60°C. After drying, the samples were reconstituted in 100 microliters of ethyl acetate. GC-MS spectra were taken using an HP 5890 GC-MS. The column temperature was programmed from 40°C to 200°C at 12 C/min. The injector temperature was set to 200, 250, and 300°C and the GC-MS interface was set at 230, 280, or 320°C. The MS was run in single ion mode and the selected ions were 82, 182, and 303.