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Nano-LC columns of different lengths (14–35 cm), 75 μm i.d., were packed with solid-core C18 particles using a conventional HPLC system at low pressure (375 bar) and without expensive tools and fittings. Solid-core particles consist of a solid, non-porous core surrounded with a shell of a porous layer with a very narrow particle size distribution. This geometry allows a faster diffusion of the analytes compared to porous particles, reducing the C term of the Knox plot. Different slurries of packing material were evaluated and tested. The packing procedure was carried out at room temperature and at 70 °C to evaluate the influence of this parameter on the overall process. The synergic action of pressure, temperature and sonication contributed to columns of various lengths in the packing process. The columns were tested at room temperature taking into account the following parameters: Knox plots, specific permeability and peak capacity. Reduced heights of theoretical plates, h, ranged between 3.8 and 5.1 at ν between 2 and 6. An LC-MS test was carried out with a Direct-EI LC-MS instrument.

We present the validation of a multiresidue method for the concurrent SPE of organochlorine (OCP) and phenoxy-acidic pesticides (PA) in river water. The two classes of compounds show very different chemical characteristics. The analyses were performed by gas chromatography–mass spectrometry and by liquid chromatography–electrospray ionization–mass spectrometry. The method was validated at three different concentrations: method limit of quantitation, 0.5 and 5 μg L−1. The recoveries were in the range 65–135% for all the target compounds and in the range 83–113% with RSD

The generation of a micro-gradient for micro HPLC capillary columns is described. The system used is a modified and improved version of a split flow gradient elution device. Gradient tests have been performed and have shown good reproducibility under all conditions. The system has been successfully coupled with a particle beam LC-MS interface and the analysis of a mixture of twenty seven basic or neutral pesticides is reported.

Very low concentrations (down to 0.2 ng/mL) of an antispasmodic drug (Eperison) can be extracted from human plasma and analyzed by GC/MS. For sample preparation and preconcentration, solid phase extraction (SPE) has been employed. A double focussing mass spectrometer was interfaced with a capillary GC column for the GC/MS analysis. The gas chromatograph was equipped with an on-column injector to avoid thermal decomposition.