TSKgel TECHNICAL INFORMATION SHEET No. 131

Transcription

1 TSKgel TECNICAL INFORMATION SEET No. Analysis of Synthetic Sweeteners in Coffee by PLC Synthetic sweeteners are used in many foods because they have fewer calories than sugar. Acesulfame potassium (Acesulfame-K), designated as a food additive in April, has times the sweetness of sugar, and because it has zero calories, is used in sweets and soft drinks as a substitute for sugar. Standards established for use in food include g/kg as a sugar substitute in foods (for coffee, etc.), and.g/kg in soft drinks. The examples shown here were produced by analyzing Acesulfame-K in coffee using a hydrophilic interaction liquid chromatography (ILIC) column. Under these analytical conditions, saccharine can also be analyzed simultaneously. Samples were pretreated in compliance with the Methods of Analysis in ealth Science and Acesulfame-K in canned coffee was analyzed. Quantitation limits (S/N=) in this analytical method were.mg/l for saccharine and.mg/l for Acesulfame-K. Also shown for reference purposes is an example of simultaneous analysis of Acesulfame-K, saccharine, and aspartame conducted under analytical conditions that comply with the Methods of Analysis in ealth Science (reversed phase chromatography using ion pair reagents). Figure. Chromatograms of standard sample (top) Coffee beverage extract (bottom) : Saccharin mg/l : Acesulfame K mg/l Retention time, (minutes) Table. Analytical conditions in ILIC mode Retention time, (minutes)

2 Table. Analytical Conditions Column: TSKgel N -6, 4.6mm ID x cm Mobile phase:.% PO 4 / acetonitrile = /7 Flow rate:.ml/min Detection: UV@nm Temperature: 4 Injection vol.: μl Figure. Procedure for pretreatment of coffee beverage. Inject g of coffee beverage into dialysis tube together with ml of internal dialysis fluid.. Place this dialysis tube into a vessel containing ml of external dialysis fluid and add external dialysis fluid to a total volume of ml.. Leave at room temperature for 4 hours while gently shaking. 4. Mix external dialysis fluid, and dilute with solvent to prepare sample to be analyzed. Internal dialysis fluid: External dialysis fluid: % phosphoric acid % phosphoric acid + % sodium chloride Figure. Simultaneous analysis by reversed phase chromatography using ion pair reagent (standard substance) : Acesulfame K : Saccharin : Aspartame (mg/l each) Retention time, min Retention time (minutes) Table. Analytical Conditions Column: TSKgel ODS-V, µm, 4.6mm ID x cm Mobile phase: mm tetra-n-propylammonium hydroxide in C O/ = /7, p 4. ( PO 4) Flow rate:.ml/min Detection: UV@nm Temperature: 4 Injection vol.: μl

3 TSKgel TECNICAL INFORMATION SEET No. 4 Analysis of Sweetener (Sucralose) in Coffee: Application example using an evaporative light scattering detector (ELSD) Sucralose (4,',6 -trichlorogalactosucrose) is a synthetic sweetener with 6 times the sweetness of sucrose, and a structure in which of the hydroxyl groups in sucrose have been selectively replaced by chlorine atoms. With a sweetness similar in character to sucrose, and lacking any bitter or metallic taste (acridity), sucralose offer excellent preservation stability and heat stability, and consequently is used in many products including beverages and desserts. Since its discovery in 976, sucralose has been approved by more than nations, and was approved in Japan in 999. Standard limits established for use in food include.8g/kg in Japanese cakes and sweets, and.4g/kg in beverages and alcoholic drinks. Usually UV detectors set at low wavelength (nm) or a RI detector are used to detect sucralose. ere, sucralose in a coffee beverage (sugarless) was analyzed using ELSD detectors in combination with a TSKgel Amide-8 ILIC column. Under these analytical conditions, analysis could be conducted simultaneously with aspartame and glycyrrhizic acid, which are also synthetic sweeteners. Figure. Structural formula of sucralose Cl C O O O O O C Cl O O O C Cl Figure. Chromatogram of standard sample (.g/l) 8 6 : Sucralose : Aspartame : Glycyrrhizic Acid Retention time time, (minutes)

4 Table. Analytical conditions Column: TSKgel Amide-8, μm, 4.6mm ID x cm Mobile phase: A: mm ammonium formate buffer (p.7) Gradient: Flow rate: Detection: Temperature: 4 C Injection vol.: μl B: acetonitrile min (9%B) min (6%B) 6min (6%B) 7min (9%B).mL/min ELSD (Agilent Technologies) Temp.: 4, Nebulizer gas; N, Gas pressure: 7kPa, Gain; 4 Figure. Pretreatment of coffee beverage (sugarless) Dilute coffee beverage fold with 9% acetonitrile aqueous solution Mix, then let stand Filter [Maishori disc (PTFE filter, pore size:.μm)], then analyze the filtrate Figure 4. Chromatogram of coffee beverage (sugarless) : Sucralose (.9 g/l) Retention Retention time, time (minutes) min

5 TSKgel TECNICAL INFORMATION SEET No. 4 Analysis of Sweeteners (Sugar Alcohols) in Food: Application example using evaporative light scattering detector (ELSD) Sugar alcohols are sugars produced by reducing the carbonyl group in aldose or ketose to a hydroxyl group. These sugars are not readily absorbed in the intestine, and thus are used as sweeteners in health foods and low-calorie foods. RI detectors are generally used to analyze sugar alcohols in food, but because gradient elution cannot be used, simultaneous analysis of more than one component is difficult. ere, various sugar alcohols were separated using the ILIC in gradient elution, with detection performed by ELSD. Also shown are application examples for analysis of sugar alcohols in sugarless candy and functional jelly beverages. Table. Analytical conditions Column: Mobile phase: A: water Gradient: Flow rate: Detection: Temperature: Injection vol.: μl TSKgel Amide-8, μm, 4.6mmI.D. x cm B: acetonitrile min (97%B) min (7%B) min (7%B) min (97%B).mL/min ELSD (Agilent Technologies) Temp.: 4, Nebulizer gas; N, Gas pressure: 6kPa, Gain; Figure. Chromatogram of sugar alcohols (.g/l each) Retention time time, (minutes) Samples:.erythritol. mannitol. adonitol 6. inositol. xylitol 7. maltitol 4.sorbitol 8. lactitol

6 Figure. Pretreatment of functional jelly beverages and sugarless candy Weigh out.g of functional jelly beverage (.g of sugarless candy), and add ml of water Shake and heat Filter supernatant [(Maishori disc W (cellulose acetate, pore size:.4μm)] Take ml of filtrate and dilute fold with 8% acetonitrile aqueous solution After filtering [(Maishori disc (PTFE, pore size:.μm)], analyze filtrate Figure. Chromatogram of functional jelly beverage : Erythritol (.87g/L) Retention time, (minutes)

7 Figure 4. Chromatogram of sugarless candy : Erythritol (.64g/L) : Xylitol (.g/l) : Maltitol (.7g/L) Retention Retention time time, (minutes) TIS4 8 TSKgel is a registered trademark of Tosoh Corporation.