Spectrophotometric determination of boron in dates of some cultivars grown in Saudi Arabia.

The formation of a red complex between boron and the quinalizarin reagent was investigated and used as the basis for a simple and sensitive spectrophotometric method for boron in date cultivars. At 620 nm, the absorbance was linear (r = 0.999) over the 0.25-2.5 micrograms/mL concentration range. The molar absorptivity was found to be 2.23 x 10(3) mol-1 cm-1 and the relative standard deviation for 10 replicates (1.0 micrograms/mL) was 0.97%.