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The worldwide consumption of illicit drugs presents a big problem in terms of health care and prosecution. In the recent years, hundreds of novel psychoactive substances came up and were traded via the Internet, but there is still a big demand for classic illicit drugs such as cocaine, heroin, cannabis and ecstasy. Among these, cocaine particularly is frequently altered not only with excipients, but also with other physiologically active substances. The purpose of this work was to estimate the trend of cocaine purity and abundance of its adulterants in samples seized by Austrian police from 2012 to 2017. A micro-HPLC method for quantification of cocaine and its most common adulterants was developed and validated using gradient elution and UV detection at four wavelengths. 110 cocaine samples were analysed. In all the samples cocaine was present as hydrochloric salt. Caffeine, procaine, levamisole, phenacetin, lidocaine and benzocaine were the most abundant adulterants.

The purpose of this study is to improve the detection limit for trace herbicides, and to separate all samples within a short time with the combination of temperature and flow programming with micro‐reversed‐phase liquid chromatography (RPLC). The optimum condition for separation was ACN:0.05 M NaH2PO4 (46:54) (v/v), pH = 4.3, 40°C. The mass sensitivity is in the range between 0.086 × 10−13 g and 3.34 × 10−13 g in micro‐HPLC (HPLC). Micro‐HPLC exhibits higher mass sensitivity and better heat transfer than conventional HPLC. Thus, in the case of micro‐HPLC, the retention behavior of herbicides is easily determined according to the change of temperature. Especially, retention of triazines is decreased to a lesser extent with the increase of column temperature than that of other herbicides. This tendency has been accounted for the thermodynamic parameters ΔH° and ΔS°. The ΔS° for triazines is less negative than that for phenoxy acids, esters, and others. The chromatograms of herbicides were obtained ...