EN ISO 15681-1:2004

Foreword
Introduction
1 Scope
2 Normative references
3 Interferences
   3.1 General interferences
   3.2 Interferences in the determination of total-P
4 Principle
   4.1 Determination of orthophosphate
   4.2 Total phosphorus with manual digestion
5 Reagents
6 Apparatus
   6.1 Flow injection analysis (FIA)
   6.2 Additional apparatus
   6.3 Additional apparatus for the determination of total
       phosphorus
7 Sampling and sample preparation
8 Procedure
   8.1 Analysis preparation
   8.2 Instrument performance check
   8.3 Reagent blank check
   8.4 Calibration
   8.5 Check of digestion efficiency for determination of
       total-P
   8.6 Measurement
   8.7 Closing down the system
9 Calculation of results
10 Expression of results
11 Test report
Annex A (informative) Example of an FIA system
Annex B (informative) Precision and accuracy
Annex C (informative) Determination of orthophosphate-P and
                      total-P by FIA using ascorbic acid
                      reduction
Annex D (informative) Replacement of hydrazine sulfate by DEHA
                      (N,N-diethylhydroxylamine)
Bibliography

ISO 15681-1:2003 specifies flow injection analysis (FIA) methods for the determination of orthophosphate in the mass concentration range from 0,01 mg/l to 1,0 mg/l (P), and total phosphorus by manual digestion in accordance with ISO 6878 for the mass concentration range from 0,1 mg/l to 10 mg/l (P). The range of application can be changed by varying the operating conditions.ISO 15681-1:2003 is applicable to various types of water (such as ground, drinking, surface, leachate and waste waters).This method is also applicable to the analysis of seawater, but with changes in sensitivity, by adaptation of the carrier and calibration solutions to the salinity of the samples.