Aspartame with saccharin sodium

FIGURE 13-7. Effect of pH on the retention times of the beverage additives , benzoic acid , aspartame , caffeine o, saccharin. Conditions are the same as Figure 13-6 with the pH of the acetic-acid component adjusted with 50% sodium hydroxide to the desired pH. (Note Actual separation will depend upon the quality of the mobile phase and column packing.) (Reproduced from reference 6 with permission.)... 

Synergistic effects for combinations of sweeteners have been reported. Saccharin sodium is often used in combination with cyclamates and aspartame since the saccharin sodium content may be reduced to minimize any aftertaste. 

Many excipients have been associated with adverse reactions in those ingesting drugs and vitamin/mineral formulations containing these compoundsJ78 79 Antioxidants (e.g., sodium sulfite, sodium and potassium bisulfites, and metabisulfites), bacterial preservatives (e.g., benzyl alcohol and benzalkonium chloride), artificial sweeteners (e.g., aspartame and saccharine), coloring agents (e.g., FD C yellow 5, blue 2, and red 40), and propylene glycol. A few examples of the toxic effects of these follow. 

The instructor will prepare a mixed standard of the four components, consisting of 200 mg of aspartame, 40 mg of benzoic acid, 40 mg of saccharine, and 20 mg of caffeine in 100 mL of solvent. The solvent for these standards is a mixture of 80% acetic acid and 20% methanol, buffered to pH 4.2 with 50% sodium hydroxide. The lab instructor will also run an HPLC of this standard mixture beforehand, and you should obtain a copy of the results. Some of the steps described in the next two paragraphs may be completed in advance by your instructor. 

Bitencourt-Mendes et al. [90] described a method for saccharin determination in liquid sweetener products. The method is based on the precipitation reaction of Ag(I) ions with saccharin in aqueous medium (pH 3.0), using a FIA system with merging zones, the suspension was stabilized with 5 g/L Triton X-100. Based on interference studies performed with the substances commonly found in liquid sweeteners, such as sodium cyclamate, methylparaben, sodium aspartame, and benzoic and citric acids, at the analyte-to-interferent mole ratio of up to 1 10 no interference with the saccharin determination was observed. The presence of chloride ions interferes with the method, but a preceding liquid-liquid saccharin extraction with ethyl acetate was successfully employed to overcome this drawback. 

The artificial sweeteners erythritol, sodium saccharin, and aspartame (Fig. 25) were also studied. Figure 26 shows potential oscillation in the presence of these artificial sweeteners [22]. The oscillation modes of these substances differed considerably. For erythritol above 10 mM, Fa.sds slightly shifted to more negative potentials. and Fb.sds were essentially unaffected by this sweetener. Erythritol thus induces change in the oscillation mode in much the same way as sugars. At 1 mM-1 M sodium saccharin, E and Fa.sds shifted to more negative values with increase in its concentration. For aspartame at less than 10 mM, there was no change in potential. 

Chen et al. (1997a) analysed sodium saccharin in soft drinks, orange juice and lemon tea after filtration by injection into an ion-exclusion column with detection at 202 nm. Recoveries of 98-104% were obtained. They reported that common organic acids like citric and malic and other sweeteners did not interfere. Qu et al. (1999) determined aspartame in fruit juices, after degassing and dilution in water, by IC-PAD. The decomposition products of aspartame, aspartic acid and phenylanaline were separated and other sweeteners did not interfere. The recoveries of added aspartame were 77-94%. Chen et al. (1997b) separated and determined four artificial sweeteners and citric acid. 

There is a recent trend towards simultaneous CE separations of several classes of food additives. This has so far been applied to soft drinks and preserved fruits, but could also be used for other food products. An MEKC method was published (Lin et al., 2000) for simultaneous separation of intense sweeteners (dulcin, aspartame, saccharin and acesulfame K) and some preservatives (sorbic and benzoic acids, sodium dehydroacetate, methyl-, ethyl-, propyl- and isopropyl- p-hydroxybenzoates) in preserved fruits. Ion pair extraction and SPE cleanup were used prior to CE analysis. The average recovery of these various additives was 90% with good within-laboratory reproducibility of results. Another procedure was described by Frazier et al. (2000b) for separation of intense sweeteners, preservatives and colours as well as caffeine and caramel in soft drinks. Using the MEKC mode, separation was obtained in 15 min. The aqueous phase was 20 mM carbonate buffer at pH 9.5 and the micellar phase was 62 mM sodium dodecyl sulphate. A diode array detector was used for quantification in the range 190-600 nm, and limits of quantification of 0.01 mg/1 per analyte were reported. The authors observed that their procedure requires further validation for quantitative analysis. 

Reverse-phase chromatography has been used extensively for the determination of saccharin. Smyly et al. (30) and Eng et al. (39) used /rBondapak Cl 8 and 5% acetic acid for the determination of saccharin. Based on this work, an Association of Official Analytical Chemists (AOAC) collaborative study was conducted, and the method using a mobile phase buffered to pH 3 with sodium acetate and modified with 3% isopropanol was adopted. Webb and Beckman (61) used this method successfully for the separation of saccharin from aspartame, caffeine, sodium benzoate, and artificial colors and flavors. Veerabhadrarao et al. (27) added methanol to the mobile phase (methanol acetic acid water, 4 1 1, v/v) for improved separation of saccharin from caffeine, benzoic and p-hydroxybenzoic acids, vanillin, aspartame, acesulfame-K, and dulcin. Saccharin was also determined using LiChrosorb Cl8 and 4 6 v/v methanol phosphate buffer,... 

With the general name of cyclohexylsulphamate, this sweetener was discovered in 1937 by Michael Sveda at the University of Illinois. The sodium salt is the most commonly used form. It is a white crystalline salt with good solubility. The relative sweetness of cyclamate is comparatively low, at approximately 35, in most food systems (Bakal, 1983). The taste quality of cyclamate as a sole sweetener has a slow onset time and can have a sweet/sour aftertaste at high concentrations (Franta et al., 1986). Sweetness quality is greatly unproved in combination with other sweeteners. Cyclamate is synergistic with acesulfame K (Von Rymon Lipinsky, 1985), aspartame (Searle, 1971), saccharin (Von Rymon Lipinsky, 1987) and sucralose (Tate Lyle Pic, 2002). 

Titrimetric methods Titrimetric assays have been developed for acesulfame-K (titrated with sodium methoxide in benzene), aspartame, sodium cyclamate, and sodium saccharin (titrated with perchloric acid), and for saccharin (acid form) with potassium hydroxide as titrant. Precipitation, chelatometric, and redox titrations are proposed for the determination of cyclamate. The oldest methods for saccharin involve its determination by means of a Kjeldahl procedure. 

RPLC with MS detection was used for the analysis of seven artificial sweeteners (aspartame, saccharin, acesulfame-K, neotame, sucralose, cyclamate, and alitame) and one natural sweetener (stevioside). Samples were extracted using methanokwater and injected without any cleanup into the LC—MS system. Separation is carried out using a Cis column and gradient elution. Sweeteners were quantified using selective-ionization recording (SIR) at m/z 178, 397, 377, 293, 641, 312, 162, and 182 for cyclamate, sucralose, neotame, aspartame, stevioside, alitame, acesulfame-K, and saccharin, respectively, with a warfarin sodium m/z = 307) used as an internal standard [24]. For a detailed discussion of other analytical methods to determine artificial sweeteners, refer to [25]. 

A flow injection system coupled to a monolithic column has been described for the simultaneous determination of antioxidants (PG and BHA), sweeteners (potassium acesulfame, sodium saccharin, and aspartame), and preservatives (methylparaben, eth-ylparaben, propylparaben, and butylparaben), using photometric detection [56]. The monolithic column used as separation system was a 5 mm commercial precolumn of silica Cjg. The mixture was separated in only 400 s with resolution factors greater than 1.1 in all cases. Detection was accomplished by means of a DAD at the respective wavelength of each compound. The detection limit obtained for PG was 0.02 pg/mL. The method was applied to the analysis of food and cosmetic samples and the results were compared with those obtained using a conventional LC method. 

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