Ammonium ion, qualitative tests

Ammonium ion, qualitative tests for, in cyanates, 2 89 Ammonium metavanadate, 3 117 Ammonium monofluorophosphate, 2 155... 

Qualitative. The classic method for the quaUtative determination of silver ia solution is precipitation as silver chloride with dilute nitric acid and chloride ion. The silver chloride can be differentiated from lead or mercurous chlorides, which also may precipitate, by the fact that lead chloride is soluble ia hot water but not ia ammonium hydroxide, whereas mercurous chloride turns black ia ammonium hydroxide. Silver chloride dissolves ia ammonium hydroxide because of the formation of soluble silver—ammonia complexes. A number of selective spot tests (24) iaclude reactions with /)-dimethy1amino-henz1idenerhodanine, ceric ammonium nitrate, or bromopyrogaHol red [16574-43-9]. Silver is detected by x-ray fluorescence and arc-emission spectrometry. Two sensitive arc-emission lines for silver occur at 328.1 and 338.3 nm. 

Further applications of coupled h.p.l.c.-m.s. systems have appeared. The efficacy of adding ammonium acetate to the mobile phase to enhance MH and [M+NH, ] ion intensities was tested with a variety of underivatized, per-Q-acetylated, and per-Q-alkylated carbohydrates. Qualitative analysis of crude saponins containing oligoglycoside and oligoglycosyl ester moieties was performed on a system with a new FRIT-FAB interface. ... 

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