Simultaneous detection and quantitation of O6-monoacetylmorphine, morphine and codeine in urine by gas chromatography with nitrogen specific and/or flame ionization detection

Novel N,Cl-doped deep eutectic solvents-based carbon dots as a selective fluorescent probe for determination of morphine in food

In the present study, new N,Cl co-doped carbon dots (N,Cl-CDs) based on deep eutectic solvent (DES) were fabricated by a facile hydrothermal process. This fluorescent probe exhibited a good quantum yield of 14% and was applied for the sensitive and selective quantification of morphine in foods. In addition, the influence of solution pH, interaction time, system temperature, interfering substances and analogues on the determination was also investigated. Under the optimized conditions, the luminescence intensity of carbon dots increased linearly with the addition of morphine in the concentration range of (0.15–280.25) μg mL⁻¹ (R² > 0.9969) and the limit of detection (LOD) of 46.5 ng mL⁻¹. Based on these results, it is suggested that N,Cl-CDs is a promising fluorescent probe for sensitive and selective quantification of morphine in foods.

A schematic illustrating the synthesis and morphine detection of N,Cl-CDs.

Morphine and its metabolites: Analytical methodologies for its determination

The present article reviews the methods of determination published for morphine and its metabolites covering the period from 1980 until at the first part of 2006. The overview includes the most relevant analytical determinations classified in the following two types: (1) non-chromatographic methods and (2) chromatographic methods.

Determination of morphine and codeine in plasma by HPLC following solid phase extraction

A cheap simple and rapid extraction procedure followed by a UV high performance liquid chromatography (HPLC) assay is described for the simultaneous determination of morphine (M) and codeine (C) in plasma. The method is based on extraction of these opiates from plasma using reversed phase (solid phase) extractions columns followed by HPLC with UV detection at 240 nm. The extraction step provides, respectively, 85 and 80% recovery for M and C. The response of the detection system is linear for both molecules in the studied range from 50 to 750 ng ml-1. No other drugs have been found to interfere with the assay. This method offers a quick, cost effective and reliable procedure for specifically determining M and C, from a small sample volume.

Hair analysis for drugs of abuse. VIII. Effective extraction and determination of 6-acetylmorphine and morphine in hair with trifluoroacetic acid-methanol for the confirmation of retrospective heroin use by gas chromatography-mass spectrometry

A procedure for the detection and determination of 6-acetylmorphine (6AM) and morphine in rat and human hair is described. The efficiency of extraction of 6AM and morphine from hair was compared between five extraction methods using methanol, 0.1 M hydrochloric acid, methanol-5 M hydrochloric acid (20:1), helicase and methanol-trifluoroacetic acid (TFA) (9:1). Methanol-TFA was found to be the best solvent for extracting 6AM and morphine with minimum hydrolysis and maximum extraction efficiency of 6AM. The extraction rates of 6AM and morphine from heroin abuser's hair with methanol-TFA reached a plateau after 8-10 h. After the extraction from hair with deuterated internal standards added, the extract was purified by Bond Elut Certify in the usual manner. The 6AM and morphine were then derivatized with bis(trimethylsilyl)acetamide, which were characterized by GC-MS with electron impact ionization. Confirmation was accomplished by comparing their retention times and the relative abundances of major four selected ions with those of the standards. Quantification was based on the deuterated internal standards. Linearity was obtained in the concentration range 0.1-50 ng/mg. The overall recoveries after solvent extraction and solid-phase purification were 95% for 6AM and 97% for morphine. The limit of detection for confirmation was 0.2 ng/mg. The coefficients of variations for 6AM and morphine at concentrations of 4 ng/mg were generally less than 8%. 6AM was stable during extraction with methanol-TFA (9:1) at room temperature. This method was applied to the elucidation of heroin drug history by using hair sectional analysis.

A safer methylation procedure with boron trifluoride-methanol reagent for gas chromatographic analysis of ritalinic acid in urine

Ritalinic acid (RITA), the major metabolite of methylphenidate (Ritaline) is extracted with a solid-phase C8 column. Following elution, methylation of the carboxylic group is performed with boron trifluoride-methanol as a reagent. The methyl ester of RITA which structurally corresponds to the parent compound methylphenidate is reextracted at pH 9-11. Each step of the analytical method has been systematically studied, particularly the parameters governing the esterification reaction with BF3-methanol. The recovery from the overall method is 96%. The limit of detection is 0.05 micrograms ml-1 with GC-NPD for a 10-ml urine sample. The method has been successfully applied to the detection and quantitation of RITA in urine specimens. The specificity of the methylated RITA peak has been verified by GC-MS in scan mode. Use of diazomethane or sulphuric acid is thus replaced by the use of a less hazardous reagent.