Microanalytical azomethine‐H method for boron determination in plant tissue

Abstract

Abstract A microanalytical technique for boron determination using the azomethine‐H reagent was developed. The effects of sample size, extractant and extracting conditions were tested. The technique is quite sensitive to minute amounts of B with a minimum threshold of 05 ppm B. Determinations of B in orchard leaves, NBS reference material No. 1571, agreed with the certified value of 33 ± 3 ppm B, routinely producing a 3% coefficient of variation. The most efficacious procedure resulted from dry ashing a 20 mg oven‐dried sample at 500°C and extracting in 200 μl 1.0N sulfuric acid for 1 hr at 20°C. Key words: Boron determinationmicrotechniqueplant tissueazomethine‐H