Robotic sample pretreatment-immunoassay determination of chlorpyrifos metabolite (TCP) in soil and fruit.

A fully automated method for leaching of TCP (3,5,6-trichloro-2-pyridinol, the major degradation product of the widely used chlorpyrifos insecticides) from soil and fruit with subsequent determination by ELISA is reported. The automation of the weighing and leaching steps enables unattended development of sample preparation. The determination of the target analyte, traditionally performed by liquid chromatography, has been substituted by specific immunoassay using a non-commercial monoclonal antibody which enables the determination of TCP within the range 0.01-7 ng 1(-1) with an R.S.D. of 8.6%.

Full automated robotic method for the determination of chloride, nitrite and nitrate in cured meat products.

A completely automated method to determine the most common parameters in cured meat products is proposed. The approach to full automation is based on the coupling of a robotic station for development of preliminary operations (namely weighing of the sample, grinding, leaching, filtration and transport to the aspiration zone) and a continuous unsegmented manifold for derivatisation and spectrophotometric monitoring of the reaction coloured products. This assembly works in an unattended fashion thus eliminating the bottleneck produced by the determination of these parameters in routine laboratories. The good agreement between results obtained by the proposed method and those from conventional methods for target analytes confirms its excellent performance and usefulness.

Fully robotic method for characterization of toxic residues.

A fully automated method for the determination of toxic residues was developed using a robotic station. The robot performs the weighing of the solid sample and applies the standard leaching method based on continuous stirring with discontinuous pH monitoring and control by addition of acid solution for 24 h; it then filters the sample and prepares the different dilutions for application of the luminescence test which is monitored by aspiration of the solutions into the flow cell of a luminescence detector. The data from both the sample mass and dilution step are used together with those from the detector by the computer for calculation of the toxicity. The two manual procedures usually applied in routine laboratories were developed by the robotic station; the results obtained by both methods were compared with those provided by the manual method and showed excellent agreement. The main advantage of the proposed method is that it is fully automated as opposed to the constant human attendance (for at least 28 h) required by the manual method.

Fully automated determination of vitamins A and E in milk-based products using a robotic station-HPLC arrangement.

An automated method, which includes an extraction procedure based on the AOAC official method of analysis for vitamins A and E in milk-based infant formula, was developed. The whole procedure is carried out automatically in a robotic station coupled to a liquid chromatograph with a UV detector for individual separation and quantification of the vitamins. Different commercial products (milk, infant formula and nutritional supplements) were analysed, and the data were compared with those obtained using the manual AOAC extraction method. Relative standard deviations using the automated method were 5.92 and 2.57% for vitamin A and E, respectively.