ISO 15681-2:2018 PDF

Scope: This document specifies continuous flow analysis (CFA) methods for the determination of orthophosphate in the mass concentration range from 0,01 mg/l to 1,00 mg/l P, and total phosphorus in the mass concentration range from 0,10 mg/l to 10,0 mg/l P. The method includes the digestion of organic phosphorus compounds and the hydrolysis of inorganic polyphosphate compounds, performed either manually, as described in ISO 6878 and in References [4], [5] and [7], or with an integrated ultraviolet (UV) digestion and hydrolysis unit. This document is applicable to various types of water, such as ground, drinking, surface, leachate and waste water. The range of application can be changed by varying the operating conditions. This method is also applicable to the analysis of seawater, but with changes in sensitivity by adapting the carrier and calibration solutions to the salinity of the samples. It is also applicable to analysis using 10 mm to 50 mm cuvettes depending on the desired range. For extreme sensitivity, 250 mm and 500 mm long way capillary flow cells (LCFCs) can be used. However, the method is not validated for these two uses. Changes in sensitivity and calibration solutions could be required. Annex A provides examples of a CFA system. Annex B gives performance data from interlaboratory trials. Annex C gives information of determining orthophosphate-P and total-P by CFA and tin(II) chloride reduction.

ISO 15681-2:2018 Referenced Document

ISO 3696:1987 Water for analytical laboratory use; Specification and test methods
ISO 5667-1:2006 Water quality - Sampling - Part 1: Guidance on the design of sampling programmes and sampling techniques
ISO 5667-3:2018 Water quality - Sampling - Part 3: Preservation and handling of water samples
ISO 6878:2004 Water quality - Determination of phosphorus - Ammonium molybdate spectrometric method
ISO 8466-1:1990 Water quality; calibration and evaluation of analytical methods and estimation of performance characteristics; part 1: statistical evaluation of the linear calibration function
ISO 8466-2:2001 Water quality - Calibration and evaluation of analytical methods and estimation of performance characteristics - Part 2: Calibration strategy for non-linear second-order calibration functions

2018 ISO 15681-2:2018 Water quality - Determination of orthophosphate and total phosphorus contents by flow analysis (FIA and CFA) - Part 2: Method by continuous flow analysis (CFA)
2003 ISO 15681-2:2003 Water quality - Determination of orthophosphate and total phosphorus contents by flow analysis (FIA and CFA) - Part 2: Method by continuous flow analysis (CFA)