Stability of Morphine, Morphine-3-Glucuronide, and Morphine-6-Glucuronide in Fresh Blood and Plasma and Postmortem Blood Samples

Abstract

The present study was designed to determine the stability of morphine and its glucuronides in spiked fresh blood and plasma from live individuals as well as in four authentic postmortem blood specimens for a time interval of up to six months. The samples were stored in glass vials at -20 degrees C, 4 degrees C, and 20 degrees C. Additionally, spiked samples were exposed to light through window glass and subjected to a forced-degradation study at 40 degrees C. Data were established using solid-phase extraction and high-performance liquid chromatography coupled to atmospheric pressure ionization mass spectrometry for isolation and quantitation, providing a sensitive and specific detection method for the parent drug in the presence of its glucuronide metabolites. Morphine and its glucuronide metabolites were found to be stable in both blood and plasma at 4 degrees C for the whole observation period. In postmortem blood the analytes were stable only when stored at -20 degrees C. The thermal decomposition of morphine and morphine-6-glucuronide in spiked blood and plasma could be interpreted using pseudo first-order kinetics. Photodegradation of morphine-3-glucuronide in plasma was consistent with a second-order reaction. In postmortem samples the degradation pattern differed completely from that observed in fresh blood and plasma. The elevated morphine levels observed were primarily due to postmortem hydrolysis of morphine glucuronides.

Postmortem redistribution of the heroin metabolites morphine and morphine-3-glucuronide in rabbits over 24 h

“…[4] and 3) conversion of morphine glucuronide(s) to morphine [53]. If there is movement of morphine post mortem it would be expected to move from areas of high free morphine concentration to areas of low free morphine concentration.…”

Zopiclone degradation in biological samples : Characteristics and consequences in forensic toxicology

“…This is an interesting finding that might be explained by pH shift in the matrices where a low pH is favorable for ZOP stability [117]. The pH of post-mortem blood tends to be acidic, whereas an alkaline shift takes place in fresh heparinized blood after storage at 4°C and at 20°C but not at -20°C [33]. In whole blood preserved with sodium fluoride an alkaline shift was observed initially but without any noticeable change during the remaining storage period (Paper IV).…”

“…whole blood, plasma, serum and/or urine), aliquoted and stored at the same time and in the same way as ordinary samples. The concentrations are measured at selected time intervals and compared to detect any trend regarding degradation [29][30][31][32][33][34][35][36][37][38][39][40]. Among reported investigations, also studies on authentic material from volunteers dosed with the drug or from laboratory cases have been performed [33,[40][41][42][43][44].…”

“…Specific stability studies of several forensically important drugs in blood and other fluids or tissues have been published including cocaine, its metabolites and its degradations product in whole blood, post-mortem blood or plasma [32,37,45,46], benzodiazepines, antidepressants, antipsychotics, analgesics and/or hypnotics in whole blood, plasma or post-mortem blood [29,30,43,[47][48][49][50][51], morphine and/or its glucuronides and/or buprenorphine in whole blood, plasma or post-mortem blood [31,33,52], 11-nor-Δ 9 -carboxy-tetra-hydrocannabinol glucuronide (THCCOOglu) in plasma [38,53], toluene and acetone in liver, brain and lungs [39], 3,4-methylenedioxymethamphetamine (MDMA), 3,4-methylenedioxyethylamphetamine (MDEA) and 3,4-methylene-dioxyamphetamine (MDA) in whole blood [34], carbon monoxide in post-mortem blood [54], GHB in blood, serum or post-mortem blood [44,55,56] and ethanol in whole blood, plasma, post-mortem blood or vitreous humor [40,57,58].…”

Study of the Ratio between Morphine-3-β-D-Glucuronide and Morphine-6-β-DGlucuronide in Blood Samples from Heroin Fatalities

“…In the last years, however, increasing interest has grown towards the role of these metabolites in mediating heroin or morphine action [14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29]. This paper describes a SPE extraction procedure and a validated LC/MS-MS method for the simultaneous determination of heroin metabolites in post-mortem blood samples.…”