Tartaric acid spectrometry

Numerous examples of stereospecific reactions in the gas phase are reported in the mass spectrometric literature [1,2]. Many if not most of them, however, deal with relatively rigid systems, e.g., 1, or polyfunctional molecules such as derivatives of tartaric acid [6] the latter gave rise to the first chirality effect observed in mass spectrometry [7]. For stereogenic centers linked by flexible alkyl chains, however, diastereoisomeric differentiation in ion fragmentation is often poor. Two epimers of the aminoalkanol 2, for example, show quite small differences in their mass spectra whereas these differences increase if the two centers are linked by cyclization upon formation of 3 as indicated in Scheme 2 with the epimeric center being marked by an asterisk [8]. 

Ayora-Canada, M. J. and B. Lendl. 2000. Sheath-flow Fourier transform infrared spectrometry for the simultaneous determination of citric, malic and tartaric acids in soft drinks. Anal. Chim. Acta 417(l) 41-50. 

Phosphorus is analyzed by atomic absorption and ICP emission spectrometry and neutron activation techniques. The total phosphorus contents can be estimated colorimetrically by classical wet methods (American Public Health Association... 1995). Phosphorus is oxidized to orthophosphate by digesting with potassium persulfate. The solution is treated with ammonium molybdate and antimony potassium tartarate in an acid medium to form an antimony-phosphomolybdate complex that is reduced by ascorbic acid to form a deep blue coloration, the intensity of which is proportional to the concentration of phosphorus. The absorbance is measmed at 650 nm by a spectrophotometer. Alternatively, it can be analyzed colorimetrically by an autoanalyzer (Technicon model). 

The most frequently studied organic acids are a-hydroxyacids, such as glycolic, citric, lactic, tartaric, etc. Glycyrrhizic and glycyrrhetinic and others can also be determined. Most of the methods are based on the use of LC. CE, GC, infrarred spectrometry (IR) and other techniques are sometimes used. Fatty acids and derivatives are determined by GC or LC. 

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