Determination of Boron in Water, Nutrient Media, and Chlorella Cells

Methods are presented for determining submicrogram amounts of boron in distilled water, nutrient media, and in Chlorella cells Boron is determined colorimetrically as a boron-curcumin complex after the sample is either dried or ashed in the presence of calcium hydroxide Boron is removed from distilled water by passing it through a column of Dowex-1 ion exchange resin in the hydroxl form Ions which interfere with the boron analysis are removed on small columns of Dowex-1 and Dowex-50 in the formate and sodium forms, respectively. Neither of the columns retains boron. Approximately 80% of a 1-μg boron standard added to Chlorella cells is recovered when calcium hydroxide is used to trap the boron during the evaporation and ashing steps Regardless of the amount of boron supplied to Chlorella during its growth, only trace amounts of boron were found in the cells