Polarographic determination of ascorbic acid in roselle juice samples
Ascorbic acid which is also known as vitamin C cannot be synthesised in human body. Hence, it is important to get the vitamin C from other source such as roseile juice. The recommended daily intake of vitamin C is 60 mg/day. Polarography technique has been used to determine the concentration of v...
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| Format: | Monograph |
| Language: | English |
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Universiti Sains Malaysia
2015
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| Online Access: | http://eprints.usm.my/60469/ http://eprints.usm.my/60469/1/ROSLINA%20BINTI%20OMAR%20-%20e.pdf |
| _version_ | 1848884454366380032 |
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| author | Omar, Rosila |
| author_facet | Omar, Rosila |
| author_sort | Omar, Rosila |
| building | USM Institutional Repository |
| collection | Online Access |
| description | Ascorbic acid which is also known as vitamin C cannot be synthesised in human
body. Hence, it is important to get the vitamin C from other source such as roseile juice.
The recommended daily intake of vitamin C is 60 mg/day. Polarography technique has
been used to determine the concentration of vitamin C in the roseile juice samples. The
parameters for polarography technique for ascorbic acid determination are as follows: start
potential: -0.0499 V, end potential: 0.1299 V, deposition potential: 0.55 V, deposition
time: 15 s, equilibrium time: 10 s, voltage step: 0.005951 V, voltage step time: 0.6 s,
sweep rate: 0.0099 V/s, pulse amplitude: 0.05 V, and pulse time: 0.04 s. The electrolytes
used were 10 ml deionised water and 1 ml acetate buffer with pH of 4.64. The peak
potential of ascorbic acid was found at 0.063 V. From five commercial roseile juice
samples, three of them give a positive result on the ascorbic acid content. In the analysis of
raw samples, it was found that the leaves have higher levels of vitamin C compared to
calyces. As the conclusion, polarography technique was a successful applied for the
determination of ascorbic acid in commercial roseile juice samples and raw samples such
as roseile calyces and leaves. |
| first_indexed | 2025-11-15T19:06:58Z |
| format | Monograph |
| id | usm-60469 |
| institution | Universiti Sains Malaysia |
| institution_category | Local University |
| language | English |
| last_indexed | 2025-11-15T19:06:58Z |
| publishDate | 2015 |
| publisher | Universiti Sains Malaysia |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | usm-604692024-05-13T06:27:17Z http://eprints.usm.my/60469/ Polarographic determination of ascorbic acid in roselle juice samples Omar, Rosila R Medicine (General) R735-854 Medical education. Medical schools. Research Ascorbic acid which is also known as vitamin C cannot be synthesised in human body. Hence, it is important to get the vitamin C from other source such as roseile juice. The recommended daily intake of vitamin C is 60 mg/day. Polarography technique has been used to determine the concentration of vitamin C in the roseile juice samples. The parameters for polarography technique for ascorbic acid determination are as follows: start potential: -0.0499 V, end potential: 0.1299 V, deposition potential: 0.55 V, deposition time: 15 s, equilibrium time: 10 s, voltage step: 0.005951 V, voltage step time: 0.6 s, sweep rate: 0.0099 V/s, pulse amplitude: 0.05 V, and pulse time: 0.04 s. The electrolytes used were 10 ml deionised water and 1 ml acetate buffer with pH of 4.64. The peak potential of ascorbic acid was found at 0.063 V. From five commercial roseile juice samples, three of them give a positive result on the ascorbic acid content. In the analysis of raw samples, it was found that the leaves have higher levels of vitamin C compared to calyces. As the conclusion, polarography technique was a successful applied for the determination of ascorbic acid in commercial roseile juice samples and raw samples such as roseile calyces and leaves. Universiti Sains Malaysia 2015 Monograph NonPeerReviewed application/pdf en http://eprints.usm.my/60469/1/ROSLINA%20BINTI%20OMAR%20-%20e.pdf Omar, Rosila (2015) Polarographic determination of ascorbic acid in roselle juice samples. Project Report. Universiti Sains Malaysia. (Submitted) |
| spellingShingle | R Medicine (General) R735-854 Medical education. Medical schools. Research Omar, Rosila Polarographic determination of ascorbic acid in roselle juice samples |
| title | Polarographic determination of ascorbic acid in roselle
juice samples |
| title_full | Polarographic determination of ascorbic acid in roselle
juice samples |
| title_fullStr | Polarographic determination of ascorbic acid in roselle
juice samples |
| title_full_unstemmed | Polarographic determination of ascorbic acid in roselle
juice samples |
| title_short | Polarographic determination of ascorbic acid in roselle
juice samples |
| title_sort | polarographic determination of ascorbic acid in roselle
juice samples |
| topic | R Medicine (General) R735-854 Medical education. Medical schools. Research |
| url | http://eprints.usm.my/60469/ http://eprints.usm.my/60469/1/ROSLINA%20BINTI%20OMAR%20-%20e.pdf |