Abstract
An improved preconcentration method using activated carbon loaded with zirconium (Zr-C*) allows determination of low levels of phosphorus(P) in environmental waters. The Zr-C* complex was prepared by mixing activated carbon, which was purified beforehand by immersing in 3M hydrochloric acid solution, in zirconyl nitrate solution (20 gZr⋅1-1). The Zr-C* complex was collected on a glass fiber filter and rinsed with 1M sodium hydroxide solution to decrease P in the blanks. The water sample (with pH adjusted to 2) was then filtered through the Zr-C* bed on the glass fiber filter and P in the water sample adsorbed to the Zr-C*. The adsorbed P was then recovered by eluting with IM sodium hydroxide solution. The P in the eluate was determined spectrophotometrically as molybdenum blue. The proposed preconcentration method enabled us to determine P down to 0.2μgP⋅1-1. This method was successfully applied to the waters in Lake Biwa during BITEX'93, 24 August - 12 September 1993.
