Problems of Forensic Sciences 2000 Vol. 44 (XLIV) 7-23
STABILITY OF COCAINE IN PHOSPHATE BUFFER AND IN URINE
Marianna KISZKA, Grzegorz BUSZEWICZ, Roman MĄDRO
Chair and Department of Forensic Medicine, Medical Academy, Lublin
Streszczenie
The stability of cocaine and benzoylecgonine standard solutions in phosphate buffer and cocaine solutions in three different samples of urine was evaluated. The research indicated that cocaine solution is significantly less stable than benzoylecgonine solution. Both xenobiotics were isolated from urine by means of three-step liquid-liquid extraction. Quantitative analysis was performed using the HPLC method. The effect of time (up to 90 days), temperature (+25°C, +4°C and –20°C), pH (in the range from 5 to 8) and, in the case of urine, sodium fluoride as well, was tested. It turned out that sodium fluoride did not have a noticeable influence on the degradation process of cocaine and benzoylecgonine. The stability of cocaine and benzoylecgonine increased with a decrease in samples storage temperature and a decrease in their pH. But only the freezing of samples, or their acidifying down to pH= 5 together with storage at +4°C assured the stability of the investigated cocaine and benzoylecgonine solutions for 90 days.
Słowa kluczowe
Cocaine; Benzoylecgonine; Stability; Autopsy material; Urine.