Sample and reagents were sequenced in  the holding coil in the sandwich configuration (A) using the software protocol that did not include the stop flow period (B). The flow cell had 15cm long light path and the holding coil was thermostated at 60 C.
The sampling frequency of the serial assay was 109s/hr (C) that is  lower than 124s/hr,  corresponding to 29 seconds length of  the duration  of  the sampling cycle (D). This is because data collection and evaluation causes a delay between individual cycles (see also 2.2.18.).
The calibration graph (E), nonlinear  past 400ppB  can be extended up to 800 ppB by decreasing sample volume from 75 to 50 microliters. Further extension up to 1200 ppB P can be achieved by splitting the sample zone (2.2.30.) . For higher sensitivity and  lower LOD  the SFC method should be used (2.2.26.)
When using DI water as a carrier the reagent solutions (3% ascorbic acid and 0.5% ammonium molybdate in 0.75 M sulfuric acid,) cause  a change  of baseline absorbance  in front and at the end of the peak. Programming the data collection window (22 to 25 seconds) eliminates the influence  of these baseline changes, caused by refractive index. By injecting sample into reagent sequence assembled  in the holding coil, the initial drop of baseline can be eliminated (2.2.27.), but if the injected sample  causes baseline to drop (e.g. when analyzing sea water 2.2.28.) the use of data  collection window is a recommended.

   Phosphate Assay by SHC