Zone Splitting

A flow system with zone splitting is generally designed in the single-line configuration and therefore tends to be simpler than a typical system exploiting zone sampling. 

---

TABLE 7.2 Selected Applications of Zone Sampling and Zone Splitting... 

Acyclovir Pharmaceutical formulations UV-Vis 4.8 to 17.3 50-1200 mg L 1 Sequential injection chromatography with monolithic column/zone splitting [114]... 

A1 Crystallised fruits UV—Vis N 0.1,0.6,0.8 mg L 1 Multi-commuted flow system with three analytical ranges/zone splitting [115]... 

Aminocaproic acid Pharmaceutical formulations Fluorimetry 100 to 1000 2.5 x 10 7 mol I. 1 Sequential injection analysis combined to tandem streams/zone splitting [116]... 

Ca Plants, milk, anti-acid tablets, fertilisers, rocks UV—Vis 2.15 to 754 7.0 pg L-1 Expert multi-commuted flow system/zone sampling combined with zone splitting [27]... 

Chloride Estuarine waters UV-Vis 1250 0.0—2.5% w/v Commutation for implementing zone splitting [60]... 

Creatinine Urine UV-Vis 70 0.5—2.0 g IA1 Kinetic determination based on Jaffe s reaction/zone splitting/zone stopping [120]... 

Isoniazid Drug dissolution samples Fluorimetry 10 to 240 34.3 ng mLA1 Multi-commuted flow system/zone splitting [62]... 

Phosphate Urine UV-Vis 101 0.05-3 x 10 2 mol L-1 Zone splitting/sequential injection analysis [63]... 

In the original proposal [58], three pumps with intermittent stop /go actions were used, and the feasibility of replacing the reactor Rc2 by a mixing chamber was discussed. Further, use of a single commutator to implement the innovation was demonstrated [60]. Another possibility is to exploit discretely operated pumps and valves [61]. With multicommutation facilities, implementation of the zone splitting strategy is easily accomplished [62]. 

Zone splitting is a simple and efficient strategy for attaining high (and variable) degrees of sample dilution, as demonstrated by applications listed in Table 7.2. 

Zone splitting [54], Most of the flowing sample zone is discarded and only its trailing edge is handled (see 7.4.1). As the mean analyte concentration in this portion of the sample zone is very... 

---