Analysis of multiple abused drugs and hypnotics in urine by sweeping CE.

Multiple drugs usage is very common in addicts (AD). However, some parent drugs were undetectable in urine, it was necessary to monitor their metabolites simultaneously. A sweeping CE was established for the determination of several kinds of abused drug and their metabolites in AD urine. This method was developed using chemometric experimental design to simplify the CE optimization. The capillary was filled by separation buffer (phosphate buffer (75 mM, pH 2.5) and methanol (70:30 v/v)) and then hydrodynamically injected large volume of samples into capillary (1 psi, 200 s). Following was using sweeping buffer (phosphate buffer (75 mM, pH 2.5) and methanol (90:10 v/v) containing 65 mM SDS) to sweep and stack analytes. The separation voltage was set at -15 kV (anode at detector end). During method validation, calibration plots were linear (r > or = 0.992) over a range of 0.1-3 microg/mL for codeine, ketamine, and methamphetamine, 0.15-3 microg/mL for morphine, 0.1-1 microg/mL for alprazolam and oxazepam, and 0.1-1.2 microg/mL for other other benzodiazepines and its metabolites. During intra- and inter-day analysis, relative standards and relative errors were less than 14%. The analytes could be simultaneously analyzed and have a detection limit down to 20-50 ng/mL (S/N=3). The results showed good coincidence with GC-MS or LC-ESI-MS. This method was feasible for application to detect trace levels of abused drugs in AD' urine.

Cation-selective exhaustive injection and sweeping micellar electrokinetic chromatography for analysis of morphine and its four metabolites in human urine.

A cation-selective exhaustive injection and sweeping micellar EKC (CSEI-Sweep-MEKC) was established to analyze morphine and its four metabolites, including codeine, normorphine (NM), morphine-3-glucuronide (M3G), and morphine-6-glucuronide (M6G). After SPE, the urine samples were analyzed by this CE method. The phosphate buffer (75 mM, pH 2.5) containing 30% methanol was first filled into an uncoated fused-silica capillary (40 cm, 50 microm id), then a high-conductivity buffer (120 mM phosphate, 10.3 kPa for 99.9 s) followed. The pretreated urine sample was loaded by electrokinetic injection (10 kV, 600 s). The stacking and separation were performed by using phosphate buffer (25 mM, pH 2.5) containing 22% methanol and 100 mM SDS at -20 kV, and detected at 200 nm. During method validation, calibration plots were linear (r > or = 0.998) over a range of 30-3000 ng/mL for morphine, NM, and codeine, 100-2000 ng/mL for M6G, and 80-3200 ng/mL for M3G. The LODs (S/N = 5, sampling 600 s at 10 kV) were 10 ng/mL for morphine, NM, and codeine, 35 ng/mL for M6G, and 25 ng/mL for M3G. This stacking CE method could increase 2500-fold sensitivity of codeine, when comparing with CZE. Five addicts' urine specimens were analyzed. Their results were compared with those of LC-MS-MS, and showed good coincidence. This method could be feasible for monitoring morphine and its metabolites in forensic interest and pharmacokinetic investigations.