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A novel capillary electrophoretic method for the separation of pancuronium (PM) and vecuronium (VM) ions utilizing capacitively coupled contactless conductivity detection was devised and validated. The separation was carried out in bare fused-silica capillaries (50 μm id, 75/45 cm) at 25°C. Optimal BGE was 50 mM borate buffer of pH 9.5 containing 12.5 mg/mL of (2-hydoxypropyl)-γ-CD. The samples were injected hydrodynamically at 1000 mbar for 3 s. Separation was performed at +30 kV. Under such conditions the PM and VM were base-line resolved and the separation took < 4 min. For quantification phenyltrimethylammonium iodide was used as internal standard. Calibration curves were linear for both pancuronium bromide (PMB) and vecuronium bromide (VMB) in the range 25-250 μg/mL with r> 0.9968. The limits of detection were 7 and 6 μg/mL for PMB and VMB, respectively. The accuracy tested by recovery experiment at three concentration levels of added PMB and VMB was satisfactory (95.7-102.7%, n =3, with RSD < 2.61%). The method was successfully applied to the assay of PMB and VMB in commercial injection solutions.

A sensitive capillary electrophoretic method featuring spectrophotometric detection using a commercial Z-cell was devised for the assay of 8-hydroxy-2'-deoxyguanosine (8OHdG) in human urine. Solid-phase extraction (SPE) based on hydrophilic-lipophilic-balanced RP sorbent was utilized for urine sample pretreatment and analyte preconcentration. The separation was carried out in conventional fused-silica capillaries employing a Z-cell with hydrodynamic sample injection (at 50 mbar for 12 s). The BGE (pH* 9.2, adjusted with 1 M NaOH) contained 0.15 M boric acid and 10% v/v ACN. The detection wavelength was 282 nm. The calibration curve for 8OHdG (measured in spiked urine) was linear in the range 10-1000 ng/mL; R(2) = 0.9993. The LOD was 3 ng/mL (11 nmol/L) of 8OHdG. Determination of the 8OHdG urinary levels was possible even in healthy individuals.

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Passive sampling is a rapidly developing technology, which is widely used for the monitoring of pollutants in different environments. Passive sampling offers significant advantages over traditional grab sampling. In the present review, the authors summarize the current literature on the methods of passive sampling used in the environmental monitoring of polar or semi-polar compounds in aqueous matrices. Methods of calibrating, design and deployment of samplers are also discussed. A major focus of this review is the use of polar organic compound integrative samplers (POCIS) and their use in sampling and monitoring of pharmaceuticals and personal care products (PCPs) in both equilibrium and non-equilibrium conditions.

Antiseptic agent carbethopendecinium bromide (septonex) was determined by capillary electrophoresis with capacitively coupled contactless conductivity detection. Optimal separation of this quaternary ammonium ion was achieved in BGE of pH 7.0 containing 30 mM 2-(N-morpholino)ethanesulfonic acid, 12.5 mg/mL of 2-hydroxypropyl-β-cyclodextrin and 20% v/v of acetonitrile. The separation was performed at 25°C in an uncoated fused silica capillary (50 μm id; total length, 60.5 cm; effective length, 50 cm) at 30 kV. Samples were injected hydrodynamically at 50 mbar for 6 s. For quantitative analysis, L-arginine (500 μg/mL) was used as internal standard. The calibration curve was rectilinear for 25-400 μg/mL of septonex (y=0.0113x-0.0063; r(2)=0.9992). The LOD was 7 μg/mL of septonex (at S/N=3). The run-to-run repeatability (n=6) was characterized by the RSDs of 0.18% for the migration time and 1.96% for the analyte/internal standard peak area ratio. Accuracy tested by recovery experiments at three concentration levels gave recoveries of 100.27-104.22% with RSD ≤2.19%. The method was successfully applied to the assay of carbethopendecinium bromide in eye drops. Quaternary ammonium ions having structure and size close to that of carbethopendecinium may not be resolved from the analyte.

A fast micellar electrokinetic chromatography (MEKC) method for simultaneous assay of aesculin, aesculetin, and phenylephrine was developed and validated. The separation was carried out in a fused-silica capillary (50 μm id, total length 64.5 cm, effective length 8.5 cm) with UV detection at 210 nm, temperature 25°C and separation voltage -25 kV. The samples were loaded hydrodynamically at a pressure of -50 mbar for 6 s. The background electrolyte of pH 8.6 contained 20 mM boric acid, 60 mM SDS, and 5% (v/v) of methanol. The calibration curves were linear in the range 10-500 μg/mL for aesculin and aesculetin and 12.5-625 μg/mL for phenylephrine. The RSD values of corrected peak areas were 0.6-1.2% (n = 6) when determining 0.2 mg/mL of aesculin and aesculetin and 0.25 mg/mL of phenylephrine in prepared standard mixtures. The method was successfully applied to the assay of aesculin and phenylephrine in a pharmaceutical preparation (RSD  =  1.9-2.0%; n  =  3) and the robustness of the method for both, the determination of analytes and the system suitability test parameter values, was evaluated with the use of Plackett-Burman design.