Abstract
A SPECTROPHOTOMETRIC METHOD FOR DETERMINING LOW LEVELS OF WATER-SOLUBLE BORON IN FERTILIZERS UTILIZES THE CARMINE COLOR DEVELOPMENT AFTER THE BORON HAS BEEN EXTRACTED AND INTERFERING IMPURITIES REMOVED WITH 2-ETHYL-1,3-HEXANEDIOL IN CHLOROFORM. AFTER EXTRACTION, ALIQUOTS ARE ACIDIFIED WITH HCL AND H2S04 AND A KNOWN VOLUME OF CARMINE SOLUTION ADDED. ABSORBANCE OF THE COLORED SOLUTION IS MEASURED AT 600 NM AGAINST A REAGENT BLANK. RECOVERY OF BORON INCREASED WITH A DIOL CONCENTRATION UP TO TEN PERCENT; THE DESCRIBED PROCEDURE GAVE A 90 PERCENT RECOVERY USING A 10 PERCENT DIOL SOLUTION. A 5-MINUTE EXTRACTION WITH AN AQUEOUS NAOH SOLUTION RESULTED IN MAXIMUM RECOVERY OF BORON. SIX COMMERCIALLY AVAILABLE INORGANIC FERTILIZERS WERE ANALYZED FOR BORON BY THIS METHOD. SAMPLES OF EACH OF THESE FERTILIZERS WERE SPIKED WITH KNOWN AMOUNTS OF BORIC ACID AND AGAIN ANALYZED. AVERAGE RECOVERY FOR THESE SAMPLES WAS 102.4 PERCENT. (SYNDER-BATTELLE)