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Vitamin C Determination in Various Fruit Juices Over Time

Vitamin C Determination in Various Fruit Juices Over Time. Andrew Mullenax Sam Yatzkan. Instrumentation. UV-Vis LC/MS HPLC. Procedure. Samples diluted 1:10 (v/v) Room Temperature Half Opened, Half Closed Vacuum Filtered-Samples with visible solids. Samples. Simply Lemonade Brand.

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Vitamin C Determination in Various Fruit Juices Over Time

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  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 Simply Lemonade Brand Dole 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 H2O and Methanol • LC/MS: Retention Time of ~1.6 minutes • Solvent Mixture of .75mL/min degassed Methanol and .25mL/min degassed H2O

  6. Data – UV-Vis

  7. HPLC Calibration Curve

  8. Data - HPLC

  9. LC/MS Calibration Curve

  10. Data – LC/MS

  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.

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