Detection of Cocaine in Seized Drug Samples by Capillary Electrophoresis Tandem Mass Spectrometry
A methodology using capillary electrophoresis with tandem mass spectrometry detection (CE-MS/MS) was developed, and applied to determine the cocaine content of seized drugs. The cocaine separation among other concomitants by capillary electrophoresis was achieved in just 4.0 minutes using 30 mM ammonium formate, pH 6.5, as a background electrolyte (BGE). The correlation coefficient of the calibration curve in the range of 0.02 to 1 μg/mL was upper 0.999, and the limits of detection (LOD) and limits of quantification (LOQ) were 0.003 μg/mL and 0.01 μg/mL, respectively. The relative standard deviation repeatability (intraday and interday) was less than 6.5% (peak area). The analysis of seized suspected illegal drugs revealed the presence of cocaine in 93% of samples (n = 11), in amounts ranging from 0.04 to 429 mg/g, showing a high variability of concentrations of cocaine. The user can change the provider and, due to the large variability of concentration, be lead to an accidental overdose.
Comparison analysis of illicit cocaine samples.
A rapid method for comparison analysis of illicit cocaine samples has been developed. The raw data are obtained by capillary gas chromatography using a nitrogen-phosphorus detector. The area ratios of four alkaloids (tropacocaine, norcocaine, cis-cinnamoylcocaine, and trans-cinnamoylcocaine) to cocaine are calculated for each sample. These ratios are compiled in a computer database which allows easy comparison of samples and makes possible reliable conclusions regarding their commonality of origin.
Melanocins A, B and C, new melanin synthesis inhibitors produced by Eupenicillium shearii. I. Taxonomy, fermentation, isolation and biological properties.
New melanin synthesis inhibitors, melanocins A, B and C, were isolated from the fermentation broth and mycelium extract of Eupenicillium shearii F80695. Melanocin A, an isocyanide compound, inhibited mushroom tyrosinase and melanin biosynthesis of B16 melanoma cells with IC50 value of 9.0 nM and MIC value of 0.9 microM, respectively. Melanocin A also inhibited growth of Streptomyces bikiniensis. While, the structurally very related but non-isocyanide compounds melanocins B and C did not show inhibitory activity in these assays. Melanocins A, B and C showed potent antioxidant activity with scavenging activity of DPPH radical and superoxide anion radical.