Sulfated Ash

Sulfated ash in lubricating oils in greases NF T 60-143 ISO 3987 ASTM D 874 NF T 60-144 ASTM D 128 Weight of residue after treatment of the ash by sulfuric acid and calcination As above... 

Values for the iadustrial oils were stated to be for the regular, aot the sulfated ash. 

Sulfated ash tests found in BP and EP are considered equivalent to the USP residue on ignition test, except where noted (19). ... 

Ash and Inorganic Constituents. Ash may be measured gravimetdcaHy by incineration in the presence of sulfudc acid or, more conveniendy, by conductivity measurement. The gravimetric result is called the sulfated ash. The older carbonate ash method is no longer in use. Ash content of sugar and sugar products is approximated by solution conductivity measurements using standardized procedures and conversion factors. 

XRD analysis on sulfated ash residue of new additive packages in lubricating oils has indicated the presence of nonstoichiometric mixed salts of the elements Mg, Ca, Zn, P and B [60],... 

Sulfated ash. When miconazole is tested according to the general method (2.4.14), not more than 0.1%, determined on 1 g. 

The sulfated ash in oxytetracycline is determined using the general test method ... 

Pharmacopeial compendia establish a couple of tests that should be carried out with raw material batches to determine their level of impurities. Concomitants usually detected are heavy metals, chloride, or sulfated ash. The presence of byproducts varies from raw material to raw material. Examples can be both innocuous substances such as monohydrogen phosphate, which is an impurity in dihydrogen phosphate salts and glycine, which is an impurity in alanine, and toxic substances, such as the classical enantiomer S of thalidomide. 

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