1. Vitamin C Determination in Various Fruit Juices Over Time Andrew Mullenax Sam Yatzkan

2. Instrumentation UV-Vis LC/MS HPLC

3. Procedure Samples diluted – 1:10 (v/v) Room Temperature Half Opened, Half Closed Vacuum Filtered-Samples with visible solids

4. Samples Dole Brand Simply Lemonade Brand

5. Ascorbic Acid Standards 5, 10, 20, 30ppm Spiked Samples Characterized Wavelength: 262nm HPLC: Retention Time of ~1.6 minutes – Solvent Mixture of.50mL/min degassed H 2 O and Methanol LC/MS: Retention Time of ~1.6 minutes – Solvent Mixture of.75mL/min degassed Methanol and.25mL/min degassed H 2 O

6. Data – UV-Vis Samples Day 1 Characterized Wavelength Day 2 Characterized Wavelength (nm) Day 3 Characterized Wavelength (nm) Day 4 Characterized Wavelength (nm) Cran-Apple Juice Closed255257251 Pineapple Juice Closed276278274 White Grapefruit Closed301316298 Lemonade Closed227228226 Cran-Apple Juice Opened252253250 Pineapple Juice Opened280284307 White Grapefruit Opened200331 Lemonade Opened232281

7. HPLC Calibration Curve

8. Data - HPLC SamplesDay 1 Concentration (ppm)Day 2 Concentration (ppm)Day 3 Concentration (ppm)Day 4 Concentration (ppm) Cran-Apple Juice Closed423.01094.01117.01249.0 Pineapple Juice Closed1101.0940.01171.01073.0 White Grapefruit Closed353.0354.067.099.0 Lemonade Closed69.0183.0163.0262.0 Cran-Apple Juice Opened1160.0873.0781.01231.0 Pineapple Juice Opened1296.0922.0563.0460.0 White Grapefruit Opened534.0178.464.0 Lemonade Opened35.0230.036.0

9. LC/MS Calibration Curve

10. Data – LC/MS Samples Day 1 Concentration (ppm) Day 2 Concentration (ppm) Day 3 Concentration (ppm) Day 4 Concentration (ppm) Pineapple Juice Closed264.0220.230.7 Lemonade Closed266.5291.11080.2 Cran-Apple Closed733.3126.3291.9 White Grapefruit Closed699.5640.3246.0 Pineapple Juice Opened542.230.7299.5 Lemonade Opened300.9161.1535.2 Cran-Apple Juice Opened348.7203.873.5446.4 White Grapefruit Opened924.41268.3307.2

11. Conclusion Results not very reliable since we had varying retention times Did not get very good separation in chromatographs of the samples Too difficult to tell whether or not vitamin c concentration actually decreased over time

12. Improvements To Be Made Better solvent system Better/Different Instrument Settings Dilute more Vacuum Filter All Samples Regardless

13. References Lee, H. S. HPLC Method for Separation and Determination of Nonvolatile Organic Acids in Orange Juice. JAFC, 1993, 41(11), pp. 1991-1993. Nisperos-Carriedo, M. O.; Buslig, B. S.; Shaw, P. E. Simultaneous Detection of Dehydroascorbic, Ascorbic, and Some Organic Acids in Fruits and Vegetables by HPLC. Chem. Anal. 1992, 40(7), pp 1127-1130. Silva, F. O.; Total ascorbic acid determination in fresh squeezed orange juice by gas chromatography. Food Control, 2005, 16(1), pp 55-58. V., K.; D., S.; E., M. Ascorbic acid content of commercial fruit juices and its rate of loss upon storage. Food Chemistry, 2000, 70(3), pp 325-328.