Acetylcodeine as a Urinary Marker to Differentiate the Use of Street Heroin and Pharmaceutical Heroin

Acelylcodeine (ACOD) is a synthesis by product present in street heroin but not in pharmaceutical diacetylmorphine (DAM) as used in the Swiss program Heroin-Assisted Treatment for Opiate Dependent Drug Users (HAT). ACOD was evaluated and validated as an urine marker to detect the consumption of street heroin by HAT participants. A gas chromatography-mass spectrometry method allowing the quantitation of ACOD concentrations as low as 0.2 ng/mL urine has been developed. In opiate-naïve subjects, intravenous (i.v.) ACOD showed a plasma elimination half-life of 237 ± 18 min, urine peak concentrations 2 h after administration, and a detection window of 8 h. Only 0.4 ± 0.1% was excreted unchanged, with codeine (COD) as the main metabolite. ACOD may be formed by transacetylation when i.v. DAM and oral codeine are co-administered. To avoid false-positive results, the calculation of COD/ACOD ratios is recommended. In a study with 105 HAT participants, 14% of the tested urines were ACOD positive. Only a low correlation was found between the anonymously self-declared consumption of street heroin and the ACOD positive rat

Fluctuating exciton localization in giant π-conjugated spoked-wheel macrocycles

Conjugated polymers offer potential for many diverse applications, but we still lack a fundamental microscopic understanding of their electronic structure. Elementary photoexcitations (excitons) span only a few nanometres of a molecule, which itself can extend over microns, and how their behaviour is affected by molecular dimensions is not immediately obvious. For example, where is the exciton formed within a conjugated segment and is it always situated on the same repeat units? Here, we introduce structurally rigid molecular spoked wheels, 6 nm in diameter, as a model of extended π conjugation. Single-molecule fluorescence reveals random exciton localization, which leads to temporally varying emission polarization. Initially, this random localization arises after every photon absorption event because of temperature-independent spontaneous symmetry breaking. These fast fluctuations are slowed to millisecond timescales after prolonged illumination. Intramolecular heterogeneity is revealed in cryogenic spectroscopy by jumps in transition energy, but emission polarization can also switch without a spectral jump occurring, which implies long-range homogeneity in the local dielectric environment