【国外标准】 Standard Test Method for Boron in Water

5.1 Because boron can be both essential and deleterious to plant growth, and because ingestion of large amounts can affect the central nervous system in humans, a method is required to determine its concentration in potable, natural, and wastewaters. This test method provides a means of determining the boron concentration of these waters. The holding time for the samples may be calculated in accordance with Practice D4841.5.2 Boric acid is used for chemical shim control of neutron flux in a nuclear reactor. This test method serves to determine if the boron concentration is within acceptable limits.1.1 This test method covers the determination of boron in water and wastewaters by the curcumin colorimetric-extraction method2 in concentrations between 0.1 and 1.0 mg/L. The range can be extended by dilution of the sample.1.2 Only dissolved boron is determined. This test method requires that the water sample be filtered through a 0.45-μm membrane filter before analysis.1.3 This test method is a colorimetric method that is very sensitive to low concentrations of boron in water and requires a relatively small sample volume for analysis.1.4 Precision and bias were obtained on natural and wastewaters. It is the user's responsibility to ensure the validity of this test method for waters of untested matrices.1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.