Sugars qualitative detection

The same investigators qualitatively examined the organic acids in orange juice by GLC (100). They reported the following acids lactic, oxalic, malonic, phosphoric, succinic, benzoic, adipic, malic, tartaric, iso-citric, aconitic and citric. They (100,101) also examined commercial sucrose and citric acid in an attempt to detect acidic impurities in these adulterants. Differences in the acid patterns were observed, but they concluded that the levels in sugar and citric acid were too low to be useful in detecting adulterations. 

Meyer and Wolfrom and their coworkers detected the uronic acid in the barium acid salt of heparin both qualitatively and quantitatively, and considered it to be the source of the acidity in the acid salt. Amino sugar was also estimated. These results, which cannot be said to be as precise as the elemental data, indicate a ratio of 1 1 for amino sugar and hexuronic acid. 

The most useful detection mode in IC seems to be MS. Because of its flexibility, this coupling method has numerous possible applications in ion analysis. IC coupled with spectrometric detector (IC-MS) is a modem determination method for quantitative and qualitative analysis. Similar analytes are separated by IC and subsequently detected by a mass spectrometer. Both ionic substances (anionic and cationic) and polar substances (e.g., organic acids or sugars) can be determined with this very sensitive detection system. 

Nondestructive detection methods have been used primarily for qualitative determination of sugars, but recent developments in near-infrared(WR) imaging detector arrays should enable the development of NIR video densitometers (78-80). Compared to derivatization reagents, detection limits achieved by this hyphenated technique are relatively high and exceed 1 pg per spot of selected sugar (80). 

Benedict s Qualitative Copper Reagent 17-3 gm. crystalline CUSO4.5H2O, with 173 gm. Na citrate and 100 gm. anhydrous Na2C03 in 1,000 ml. water. Used for detecting reducing sugars in urine. 

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