The application of a new microfluidic device for the simultaneous identification and quantitation of midazolam metabolites obtained from a single micro-litre of chimeric mice blood.

Rationale: Improvements in the design of low-flow highly sensitive chromatographic ion source interfaces allow the detection and characterisation of drugs and metabolites from smaller sample volumes. This in turn improves the ethical treatment of animals by reducing both the number of animals needed and the blood sampling volumes required.

Methods: A new microfluidic device combining an ultra-high pressure liquid chromatography (UHPLC) analytical column with a nano-flow electrospray source is described.

Optimisation of secondary electrospray ionisation (SESI) for the trace determination of gas-phase volatile organic compounds.

An electrospray ionisation triple quadrupole mass spectrometer (Varian 1200 L) was modified to accept nitrogen samples containing low concentrations of volatile organic compounds. Six candidate probe compounds, methyl decanoate, octan-3-one, 2-ethylhexanoic acid, 1,4-diaminobutane, dimethyl methylphosphonate, and 2,3-butanediol, at concentrations below 50 ppb(v) were generated with permeation tubes in a test atmosphere generator. The concept of using a set of molecular probes to evaluate gas-phase electrospray ionisation of volatile analytes was assessed and the feasibility of adopting a unified ionisation approach for gas and liquid contamination of exobiotic environments established.

Free flow isotachophoresis in an injection moulded miniaturised separation chamber with integrated electrodes.

An injection moulded free flow isotachophoresis (FFITP) microdevice with integrated carbon fibre loaded electrodes with a separation chamber of 36.4mm wide, 28.7 mm long and 100 microm deep is presented.