Determination of diazepam in cold drinks by high-performance thin-layer chromatography

The Electrochemical Behavior of Nitrazepam at a Screen‐Printed Carbon Electrode and Its Determination in Beverages by Adsorptive Stripping Voltammetry

“…À1 is comparable to a number of previously reported assays requiring laboratory based equipment [34] and solvent extraction of comparatively large sample volumes of 25 mL, and that reported via polarography [19]. The method gives reliable results using an external calibration method.…”

Determination of caffeine in tea samples by Fourier transform infrared spectrometry

“…Caffeine has been determined in drinks by different analytical techniques such as UV-VIS spectrophotometry [2,3,4] or amperometry [5] and most frequently by using separation methods like high performance liquid chromatography (HPLC) [6,7,10], ion chromatography [11], capillary electrophoresis [12,13,14], as well as high performance thin layer chromatography (HPTLC) [15,16,17] and micellar capillary electrophoresis [18,19,20]. The official method for caffeine determination in tea leaves [21] is based on low-pressure column chromatography and spectrophotometric determination at 276 nm.…”

Automated determination of diazepam in spiked alcoholic beverages associated with drug-facilitated crimes

“…This study involved the insertion in the analytical flow system of a 50 mg L −1 diazepam solution prepared in 0.20 mol L −1 NaOH and 0.030 mol L −1 SDS. After insertion the flowing stream was stopped under the UV light for increasing time periods, namely, 0, 1, 3,5,8,10,12,15,20 and 25 min, which corresponded to the irradiation interval. Following completion of the irradiation time, the volume of irradiated solution of diazepam equivalent to 10 pulses (100 L) was carried to the detector, using as carrier the NaOH solution.…”

“…In literature several published methods for analysis of benzodiazepines in beverages can be found based either on Gas Chromatography/Mass Spectrometry (GC-MS) [6], Capillary Zone Electrophoresis/Diode Array (CZE-DAD) [4], Direct Electrospray Probe/Mass Spectrometry (DEP/MS) [7], High Performance Liquid Chromatography/Diode Array (HPLC-DAD) [8,9], High Performance Thin-Layer Chromatography (HPTLC) [10], etc. The methods above mentioned are very precise and present high sensitivity, however they are only performed in very special laboratory conditions, and they are laborious and require skilled operators.…”