Analysis of sodium benzoate and potassium sorbate in local brands of pre-packed pineapple juices using UV-VIS spectrophotometry
Date of Publication
2004
Document Type
Bachelor's Thesis
Degree Name
Bachelor of Science in Chemistry
Subject Categories
Chemistry
College
College of Science
Department/Unit
Chemistry
Thesis Adviser
Julita C. Robles
Defense Panel Member
Nancy Lazaro-Llanos
Derrick Ethelbert C. Yu
Abstract/Summary
UV-VIS Spectrophotometry was used to analyze the chemical preservatives sodium benzoate and potassium sorbate present in two local brands of pre-packed pineapple juices purchased in Manila and Muntinlupa. The maximum limit set by the Bureau of Food and Drugs for sodium benzoate and potassium sorbate in food are 0.1 % (5mg/5 mL) and 0.3 % (15mg/mL) respectively. The AOAC Official Method 980.17 (Preservatives in Ground Beef) was adapted for the quantitative determination of these preservatives. Standard solutions of sodium benzoate and potassium sorbate were extracted using petroleum ether and 1:1 M hydrochloric acid and the absorbance of the standard and sample solutions were measured at 2גּmax = 228 (benzoic acid) and גּmax = 255 (sorbic acid). Results show that Brand X (Manila) contains 0.295 mg/mL sodium benzoate (2.00 % RSD) and 0.0853 mg/5 mL potassium sorbate (3.70 % RSD) while Brand X (Muntinlupa) contains 0.0878 mg/5mLsodium benzoate (6.00 & RSD) and 0.278 mg/5mL potassium sorbate (9.10% RSD). Brand Y (Manila) contains 0.321 mg/5mL sodium benzoate (4.50 %RSD) and 0.0212 mg/5mL potassium sorbate (2.30 %RSD) while Brand Y (Muntinlupa) contains 0.0197 mg/5mL sodium benzoate (6.60 % RSD) and 0.113 mg/5mL potassium sorbate (5.60 % RSD). The concentration of these additives in the juice samples were found to be within the limits set by the Bureau of Food and Drugs. Standard addition was found to be not suitable because of the significant deviations from linearity between the absorbance and concentration of the added standard solution.
Abstract Format
html
Language
English
Format
Accession Number
TU17470
Shelf Location
Archives, The Learning Commons, 12F, Henry Sy Sr. Hall
Physical Description
90, [4] leaves : illustrations (some color) ; 28 cm.
Keywords
Sodium benzoate; Benzoates; Potassium; Spectrophotometry; Pineapple; Fruit juices
Recommended Citation
Lo, P. S., & Viray, P. G. (2004). Analysis of sodium benzoate and potassium sorbate in local brands of pre-packed pineapple juices using UV-VIS spectrophotometry. Retrieved from https://animorepository.dlsu.edu.ph/etd_bachelors/8926