Total Morphine Stability in Urine Specimens Stored under Various Conditions

Abstract

The stability of total morphine in urine stored under various conditions was studied using control and experimental specimens. Samples in the control group were prepared using drug-free urine spiked with morphine at three concentration levels (300, 1000, and 2500 ng/mL), each with the pH adjusted to 5.5, 6.5, and 7.5. Samples in the experimental group came from 20 alleged heroin addicts (provided by Taipei Municipal Psychiatric Hospital). Samples in both groups were divided into two categories--one with and one without the precipitate (formed at 0 degrees C) removed. Samples in each of these two categories were further divided into two sub-groups--one with and one without sodium azide (0.05%) added. Total morphine contents in these samples were first determined by gas chromatography-mass spectrometry prior to storage and at 6, 12, 18, and 24 months following storage at -20, 4, 25, and 35 degrees C. Effects of sample treatment (azide addition and precipitate removal), pH, and storage temperature and length were evaluated by examining the percentage of total morphine remaining at the four time intervals following the initial determination. Major findings were as follows: (1) total morphine decomposition was minimal when stored for 12 months at -20 degrees C, which is a common current practice; (2) samples with lower initial sample pH had slower total morphine decomposition rates; and (3) azide addition appeared to have no detectable effect, whereas precipitate removal appeared to marginally reduce the decomposition rate, especially for samples with lower pH.

Urinary Excretion Profiles for Total Morphine, Free Morphine, and 6-Acetylmorphine Following Smoked and Intravenous Heroin

“…Morphine mean recoveries + SEM were 95 • 0.3%, 100 • 0.5% and 102 • 0.2%, respectively. This agreed with previously reported Time (h) studies (25). 6-AM recoveries were 12 + 1%, 21 • 0.6%, and 106…”

Stability studies of amphetamine and ephedrine derivatives in urine

“…This issue increased the interest of toxicological laboratories to ensure that analyte instability will not affect analytical results during the retesting period. A large body of data is available on the stability in urine of phencyclidine [7][8][9], lysergic acid diethylamide [9][10][11][12][13], cannabinoids [8][9][10][11][12][13][14][15][16][17][18][19][20], morphine and codeine [8,9,17,[21][22][23][24][25][26], and cocaine/benzoylecgonine [8,10,15,17,[26][27][28][29].…”

Stability of Morphine, Codeine, and 6‐Acetylmorphine in Blood at Different Sampling and Storage Conditions

“…Only the identification of 6‐acetyl‐morphine in biological samples provides unequivocal proof of heroin use . Several studies have been reported concerning the stability of opiates in different biological samples, for example, plasma, serum, or blood , urine , hair , and oral fluids , but some factors have not been fully addressed. The purpose of this study was to investigate the effects of the type of sampling tubes, the addition of preservative and the type of anticoagulant on the stability of morphine, codeine, and especially 6‐acetyl‐morphine in blood samples.…”