Abstract: In this contribution, a new calibration technique for flow injection analysis is presented. The technique is based on a multiple-injection system complemented with multivariate evaluation. A standard the sample and another standard solution are injected in a fast sequence. A partial mixing of the solutions occurs due to dispersion. However, the overlapping measurement signals can be deconvoluted reliably employing partial least-squares regression. The simultaneous calibration technique enables a fast adaptation to changes in the reaction system, while the time lost by rapid threefold injection and the signal evaluation is minimal. Applying simultaneous calibration the change of the sensor sensitivity is considered inherently. To test the simultaneous calibration technique, it was applied to measurements of a flow injection system for the determination of glucose while the temperature of the reaction coil was changed.

Abstract: In this paper, multisyringe flow injection analysis (MSFIA) is presented as a powerful and promising tool for automated liquid-phase chemiluminescence (CL) assays. The capability of operation under discontinuous forward flow regime while handling minute, well-defined volumes of sample and reagents in a multicommuted format offers unrivalled analytical features. As opposed to the parent flow injection (FI) and sequential injection (SI) analysis, CL reactions with divergent pH and kinetic demands can be easily implemented in a single protocol sequence, as demonstrated in the bulk of the text via luminol-based methods. MSFIA is proven extremely suitable for accommodating enzymatic CL assays in a renewable fashion by exploiting soluble enzymes, with no need for the typical immobilization procedures used in FI and SI systems. Solid-phase CL sensors have also gained full advantage of the benefits of MSFIA. In this context, a novel optosensor devised for on-line monitoring of trace levels of orthophosphate is described. Similar configurations are proposed for the selective and sensitive determination of metals, Vitamins, nutrients and saccharides in environmental and biological samples as well as beverages, which denotes the versatility of this automated flow technique. Special emphasis is also given to the simple instrumental set-up, including a dedicated flow-through luminometer, arranged for a multitude of CL assays.