Portable capillary liquid chromatography for pharmaceutical and illicit drug analysis.

A newly developed portable capillary liquid chromatograph was investigated for the separation of various pharmaceutical and illicit drug compounds. The system consists of two high-pressure syringe pumps capable of delivering capillary-scale flow rates at pressures up to 10 000 psi. Capillary liquid chromatography columns packed with sub-2 μm particles are housed in cartridges that can be inserted into the system and easily connected through high-pressure fluidic contact points by simply applying a specific, predetermined torque rather than using standard fittings and less precise sealing protocols.

Stainless-Steel Column for Robust, High-Temperature Microchip Gas Chromatography.

This paper reports the first results of a robust, high-performance, stainless-steel microchip gas-chromatography (GC) column that is capable of analyzing complex real-world mixtures as well as operating at very high temperatures. Using a serpentine design, a 10 m column with an approximately semicircular cross-section with a 52 μm hydraulic diameter ( D) was produced in a 17 × 6.3 × 0.

Extending the upper temperature range of gas chromatography with all-silicon microchip columns using a heater/clamp assembly.

Miniaturization of gas chromatography (GC) instrumentation is of interest because it addresses current and future issues relating to compactness, portability and field application. While incremental advancements continue to be reported in GC with columns fabricated in microchips (referred to in this paper as "microchip columns"), the current performance is far from acceptable. This lower performance compared to conventional GC is due to factors such as pooling of the stationary phase in corners of non-cylindrical channels, adsorption of sensitive compounds on incompletely deactivated surfaces, shorter column lengths and less than optimum interfacing to injector and detector.

Dual-wavelength light-emitting diode-based ultraviolet absorption detector for nano-flow capillary liquid chromatography.

The design of a miniaturized LED-based UV-absorption detector was significantly improved for on-column nanoflow LC. The detector measures approximately 27mm×24mm×10mm and weighs only 30g. Detection limits down to the nanomolar range and linearity across 3 orders of magnitude were obtained using sodium anthraquinone-2-sulfonate as a test analyte.

Compact Ultrahigh-Pressure Nanoflow Capillary Liquid Chromatograph.

A compact ultrahigh-pressure nanoflow liquid chromatograph (LC) was developed with the purpose in mind of creating a portable system that could be easily moved to various testing locations or placed in close proximity to other instruments for optimal coupling, such as with mass spectrometry (MS). The system utilized innovative nanoflow pumps integrated with a very low volume stop-flow injector and mixing tee. The system weighed only 5.

Hand-portable liquid chromatographic instrumentation.

Over the last four decades, liquid chromatography (LC) has experienced an evolution to smaller columns and particles, new stationary phases and low flow rate instrumentation. However, the development of person-portable LC has not followed, mainly due to difficulties encountered in miniaturizing pumps and detectors, and in reducing solvent consumption. The recent introduction of small, non-splitting pumping systems and UV-absorption detectors for use with capillary columns has finally provided miniaturized instrumentation suitable for high-performance hand-portable LC.

Bioequivalence assessment of two formulations of ibuprofen.

Background: This study assessed the relative bioavailability of two formulations of ibuprofen. The first formulation was Doloraz(®), produced by Al-Razi Pharmaceutical Company, Amman, Jordan. The second forumulation was Brufen(®), manufactured by Boots Company, Nottingham, UK.

Expanded electrical model of a contactless conductivity detector: development and verification.

A theoretical model of the contactless conductivity detector (CCD) has been developed consisting of a network of resistors and capacitors. The output of the model is compared to experimental results and to the output of a simpler model. Experimentally, a lock-in amplifier is added to the detection scheme of the contactless conductivity detector to provide a more sensitive method of signal isolation.

Analysis of vitamin E derivatives in serum using coordinated ion spray mass spectrometry.

A method for the extraction and analysis of tocopherols from serum using coordinated ion spray (CIS) mass spectrometry was developed and tested. The tocopherols were extracted from serum and analyzed by direct infusion into the mass spectrometer, bypassing the need for a liquid chromatography step. CIS is a method for improving the ionization efficiency of non-polar compounds by adding metal ions to the electrospray solvent.