Arsenic in Natural Phosphates and Phosphate Fertilizer

Abstract

Introduction ___________________________________ Arsenic in calcined, sintered, nodulized, and Method oC analysis_____________________________ 1 defluorinated phosphate rocks________________ 19 Reagents and glassware____________________ 2 superphosphates phosphoric Arsenic acid in .____ and 21.Separation of arsenic Crom the sample_______ 2 Procedure used_____________________________ 3 Arsenic in ammonium phosphate, bone, and Arsenic in mineral phosphates__________________ 5 miscellaneous phosphate fertilizers .. __________ 25 Arsenic-bearing constituents._______________6 Effect of arsenic on plants and soil organisms____ 27 Primary anti secondary deposits____________ 13 Arsenic supplied to soil by superphosphate__ 28 Geologic age and arsenic content ....__ ..____ 16 Summary and conclusiol's__________________ .__20 Phosphates compared with other rocks, Literature cited___________________________ _____ 31 minerals, coals, soils, sediments, and waters____________________________________ 17 I liOO-ml.Kjl'ldahl Ollsks of Pyrex ~lass., :-<rw flasks, not pm\'iouslj' lI~ed; all oth,'r lifgl'stions wen' wade in nlk~ks that had been used a number of times.3 Florida IlInd pebble, stnndarrl snmpll' :-<0.12() of the Nati(JDal Bureau of Standards, contained a.76 percent of (luorine (78).By eareful selection of th(> chemicals and the use of low-arsenic glassware, th(> l'(~a.!:ent blanks were kept below 0.006 mg. of arSClllC throughout this invf'stigation.SEPARATION OF ARSENIC FHOllJ THE SAMPI.E " The au( ..s' l'e.cov(>ry of fl,t'senie from monopotassium a.rsena.te,alone and ',11 tll(> presence' of phosplw.trl'OCI\:, is shown in tablf' 2. The results are in good agrcomen t with those reported by Deemer and Schricker (30), 'Also, SIlETTEIIL\', F. F. Privntc communication.('ornin~ Glass I\'orks, Corning, N. Y. For exarnple, the 1II1lt,rillls listed. in tllllle 17 1.5 ~os.