Detection of methadone and buprenorphine in urine samples from inmates of German prisons.

The use of non-prescribed opioid substitution drugs is a serious public health problem, involving general population as well as vulnerable populations such as prisoners. The estimation of the prevalence of opioid substitution drug misuse in prisoners is crucial to suggest strategies to contrast this phenomenon and reduce the associated morbidity and mortality. The present study aimed to provide an objective estimation of the prevalence of illicit use of methadone and buprenorphine in two German prisons. Urine samples were collected from inmates of Freiburg and Offenburg prisons at random times and tested for the detection of methadone, buprenorphine and their metabolites. Analyses were performed by a validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. In total 678 inmates participated in this study. The participation rate was about 60% of all permanent inmates. Of the 675 samples suitable for the analysis, 70 samples (10.4%) tested positive for methadone, 70 samples (10.4%) for buprenorphine, and 4 samples (0.6%) for both drugs. At least 100 samples (14.8%) were not associated with reported prescribed-opioid substitution treatment (OST). Buprenorphine was the most common illicitly used drug. In one of the prisons, buprenorphine was brought in from the outside. The present cross-sectional experimental study was able to provide reliable information regarding the illicit use of opioid substitution drugs in prisons.

Detection of the ethanol consumption markers ethyl glucuronide and ethyl sulfate in urine samples from inmates of two German prisons.

INTRODUCTION: Abstinence from ethanol is necessary in various situations. Among these are jail terms. Nevertheless, it is a matter of fact that ethanol is illegally produced and ingested in prisons. So far, data regarding drug prevalence in jail have mainly been collected by questionnaires. To get an objective database for the prevalence of ethanol consumption in jail, a cross-sectional study was performed. METHODS: Inmates of two German prisons (Offenburg and Freiburg) were asked to give a urine sample at an unknown and random point of time. Participation was voluntary and did lead to neither negative consequences nor benefits. All samples were anonymized. Using the consumption markers ethyl glucuronide (EtG) and ethyl sulfate (EtS), the urine samples were tested for previous ethanol consumption. Analyses were performed by a validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. RESULTS: In total 676 male inmates participated in this study. The participation rate was 70-75% of all permanent inmates in Offenburg and 30.6% in Freiburg. Ten of the 555 (1.8%) samples from Offenburg and 1 of the 121 (0.8%) samples from Freiburg were positive for ethanol consumption markers with concentrations ranging from trace amounts to 1400 ng/mL for EtG and up to 510 ng/mL for EtS, respectively. CONCLUSIONS: The number of participants in this study was rather high, so that the results represent a good cross section, at least for Offenburg, the jail with the higher number of positive samples.

Modeling microalgae cultivation productivities in different geographic locations - estimation method for idealized photobioreactors.

Microalgae can be used to produce versatile high-value fuels, such as methane, biodiesel, ethanol, or hydrogen gas. One of the most important factors that influence the economics of microalgae cultivation is the primary production of biomass per unit area. This is determined by productivity rates during cultivation, which are influenced by the local climate conditions (solar irradiation, temperature). To compare locations in different climate regions for microalgae cultivation, a mathematical model for an idealized closed photobioreactor was developed. The applied growth kinetics were based on theoretical maximum photon-conversion efficiencies (for the conversion of solar energy to chemical energy in the form of biomass). Known or estimated temperature effects for different algal strains were incorporated. The model was used to calculate hourly average areal productivity rates as well as annual primary production values under local conditions at seven example locations. Here, hourly weather data (solar irradiance and air temperature) were taken into account. According to these model calculations, maximum annual yields were achieved in regions with high irradiation and temperature patterns in or near the optimum range of the specific algal strain (here, desert and equatorial humid climates). The developed model can be used as a tool to assess and compare individual locations for microalgae cultivation.