Report on Magnesium and Manganese in Fertilizers

Fertilizers

“…Contamination w7ith manganese is avoided by precipitating the phosphate in the presence of an alkali cyanide (275). Acidimetric titration of magnesium ammonium phosphate has been further investigated, wdth special reference to choice of indicator (239,264,275). The best results are obtained with methyl orange or neutral red-bromocresol green mixture; the latter gives the sharpest and most easily discernible change (264).…”

“…Although considerable attention has been given to laboratory methods of evaluating water-insoluble magnesium in fertilizer materials and mixtures (103,151,219,254,363,264,289), especially with reference to solubility in ammonium citrate solutions, no official procedure for this determination has yet been adopted.…”