Applicable to concentrations between 0.01 mg and 1 mg of boron per litre in potable water and in ground, surface and saline waters that are not heavily polluted.
BS 6068-2.40:1991 history
1991BS 6068-2.40:1991 Water quality. Physical, chemical and biochemical methods. Method for the determination of borate by spectrometry using azomethine-H