distillation ( I S ) can be used to separate fluoride from these anions.
Table IV.
Molar Absorptivities a t
Species -4cid chloranilate ion
CONCLUSION
Fluoride in aqueous solutions can be determined by this method in one hour. Sensitivity can be increased over twofold by using the higher proportion of methyl Cellosolve. The method compares favorably in sensitivity and accuracy m-ith the classical distillationtitration method. It is superior to it because it is more rapid, a wide concentration range may be covered n-ithout aliquotting, and frequent recalibration is not required. LITERATURE CITED
(1) .irmstrong, TV. D., Singer, L., A N ~ L . CHEY.26, 1047 (1954). 1 2 ) Bertolacini, R. J., Barney, J. E., Zbid., 29, 281'(1957). ' (3) Ibid., 30, 202 (1998).
__
Solvent Kater, 1:9, 1: 3, or 1: 1 methyl Cellosolve-water Water 1: 1 methyl Cellosolve-water Water 1:9 methyl Cellosolve-water 1: 3 methyl Cellosolve-water 1: 1 methyl Cellosolve-water
Thorium chloranilate complex Reaction product of fluoride ion with thorium chloranilate
(4) Brandt, W.TV., Dusmalt, A. A, Ibid., 30, 1120 (1958). (5) Fine, L., Rynne, E. A, Microchem. J., in press. (6) Harris, IT. E., ASAL. CHEM.30, 1000 (1908). (7) Johannesson, J. K., Chem. R. Ind. (London)7,81 (1957). (8) Klipp, R' (8jpKlipp,' R.. -IT., IT:,Bahey, Barney, J. E., ANAL. CHEW31,596 (1999). (9) M$on, AI. G., Boltz, D. F., Ibid., 30, a34 (1958). (10) Schlvarzenbach. Schlvarzenbach, G.. G., Suter. Suter, €1.. €I., Helv. ' dhim. Acta 24, 617 (1941). Chzm. I
330 Mp
,
dbsorptivity 24,900 27,500 31,000 8,500 12,500 16,000
29 200 ~
(11) Thatcher, cher, L. L., Xiser, R. T., A s . 4 ~ . CHEM.31, $1, 776 (1959). (12) Killard, trd, H. H., Horton, C. A , , Ibid., 22, 11001 (1950). trd, H. H., Winter, 0. B., (13) Willard, B , ISD.
