Automatic determination of boron in plants

The disadvantages of the automated procedures available for the determination of boron are the use of very acidic solutions, or difficulty in obtaining pure reagents. Boron forms a fluorescent complex with carminic acid at pH 7, and this has been used for its determination in plants, soils and water. A number of cations seriously interfere with the determination. This paper describes an automated fluorimetric method for the determination of boron using carminic acid at pH 7. The method is more sensitive than the automated procedures reported earlier, and interference by cations is eliminated by ion exchange. (author)