Acidic sulfates, differentiation

Problem Diluted acids can dissolve base metals and produce hydrogen and a salt solution. In the case of the reaction of magnesium with dilute sulfuric acid, hydrogen and magnesium sulfate solution are produced. Concentrated acids dissolve a metal too however no hydrogen is formed. In the reaction of concentrated sulfuric acid with zinc, the gas hydrogen sulfide is produced which has a rotten-egg smell. It is therefore important, in the case of sulfuric acid to differentiate between the pure acid from the diluted acidic solution and should be labeled carefully. Both reactions are not acid-base reactions - they are redox reactions (see Chap. 8). 

Differentiation of hyaluronic acid from the other glycosauninoglycusono-glycans is difficult. This has been responsible in the past for the description of non-existent entities, such as mucoitin sulfate and hyaluronic acid sulfate. 

The gaseous ammonia is passed through electrostatic precipitators for particulate removal and mixed with the cooled gas stream. The combined stream flows to the ammonia absorber where the ammonia is recovered by reaction with a dilute solution of sulfuric acid to form ammonium sulfate. Ammonium sulfate precipitates as small crystals after the solution becomes saturated and is withdrawn as a slurry. The slurry is further processed in centrifuge faciHties for recovery. Crystal size can be increased by employing one of two processes (99), either low differential controUed crystallization or mechanical size enlargement by continuous compacting and granulation. 

Synthetic ethyl alcohol (known as ethanol to differentiate it from fermentation alcohol) was originally produced hy the indirect hydration of ethylene in the presence of concentrated sulfuric acid. The formed mono-and diethyl sulfates are hydrolyzed with water to ethanol and sulfuric acid, which is regenerated ... 

The ability of sulfonic acids to form anhydrides was already described on page 81. In contrast to aqueous acids and alkalis, LAS is stable. This behavior is used in the differentiation between alkyl sulfates and alkylether sulfates, which are easily hydrolyzed from aqueous acids. 

JJ)M,A. Laccetti, S. Semel M. Roth, AnalChem 31, 1049—50(1959). The fermus sulfate-sulfuric acid method is used to differentiate HMX and RDX from NGu, Tetryl, TEGN, PETN, NG K nitrate. Following the procedure given (which requires the colorimetric measurement of the color produced on dissolving the sample in the reagent) reveals that HMX and RDX have Beet s Law... 

The pattern of spots is evaluated in reference to the standard mixture. Dermatan sulfate yields two spots, one of which can overlap with hyaluronic acid. Abnormal presence of dermatan sulfate and heparan sulfate is an indication of MPS I or MPS II, while a prominent heparan sulfate spot points to MPS III. The subtypes of MPS III can only be differentiated by enzyme studies. Elevated excretion of keratan sulfate is indicative of MPS IV. In contrast, high dermatan sulfate excretion is most likely to be associated with MPS VI, while milder cases of MPS I may also show such a pattern (cf. Table 4.1.5) [56]. 

One adaptation of this approach uses a further temperature cycle to 220 °C, which volatilizes ammonium sulfate and bisulfate in aerosols but not nonvolatile sulfates (e.g., Na2S04) (37, 40). Ammonium bisulfate and ammonium sulfate are not differentiated by this approach. Another adaptation collects the aerosol sulfuric acid on a heated denuder tube (38) for —15 min, then removes it thermally for FPD analysis while collecting another sample on a second denuder tube. Because the sample is preconcentrated in this approach, the more sensitive version of the FPD is not required. 

Vietri M, Pietrabissa A, Spisni R, et al. Differential inhibition of hepatic and duodenal sulfation of (—)-salbutamol and minoxidil by mefenamic acid. Eur J Clin Pharmacol 2000 56(6-7) 477 179. 

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