Chemical analyses, standard approach automation

For the automation of chemical analysis, incorporation of sample handhng, treatment and detection into a flow system is a popular approach [2] These flow systems can be built up from a number of standard components such as reaction coils, T-junctions, pumps, valves, detectors, etc The use of standard modules allows for a flexible setup of the systems and can easily be adapted to a specific analysis Silicon micromachining lends itself very well for the fabrication of both passive and active components of small dimensions required for the miniaturization of flow systems As the base material is usually a silicon wafer, it will be clear that the thus febricated components are in principle planar structures... 

As an example, I will use the determinations of DOC and DON, partly because the discussions are very recent and partly because they are very familiar to me. The question of the accuracy of measurements of DOC in seawater has been disputed at least since the publications of Putter [62] and Krogh [63] the early work has been reviewed at length in an earher pubhcation [64]. While a variety of wet oxidation methods [65] were proposed for marine samples, the use of persulfate [35] provided the first real approach to a standard method. Persulfate oxidation, however, hke all purely chemical oxidations, was a batch process, and not easily automated. A number of workers proposed photo oxidation using ultraviolet (UV) hght [66-70], and automated analytical systems which produced data almost in real time were soon constructed [71-73]. Commercial units soon appeared, but many of the units in the field were jerry-built, constructed out of parts scavenged from discarded autoanalyzers formerly used for nutrient analysis. 

---