Rapid and Sensitive Determination of Methylxanthines in Commercial Brands of Tea Using Ultra-High-Performance Liquid Chromatography-Mass Spectrometry

<table class="table-group" id="tab5"><tr><td><table class="table"><tr><td class="thead-hr" colspan="4"><hr/></td></tr><tr class="thead"><td class="align_left" rowspan="2">Concentration (<i>μ</i>g/mL)</td><td class="align_center" colspan="3">Mean recovery (%) ± %RSD (<i>n</i> = 3)</td></tr><tr class="thead"><td class="align_center">Theobromine</td><td class="align_center">Theophylline</td><td class="align_center">Caffeine</td></tr><tr><td class="thead-hr" colspan="4"><hr/></td></tr><tr><td class="align_left">0.1</td><td class="align_center">86.9 ± 3.6</td><td class="align_center">83.4 ± 2.2</td><td class="align_center">82.4 ± 3.7</td></tr><tr><td class="align_left">1.0</td><td class="align_center">95.7 ± 1.6</td><td class="align_center">96.6 ± 1.0</td><td class="align_center">93.7 ± 1.1</td></tr><tr><td class="align_left">3.0</td><td class="align_center">95.7 ± 1.6</td><td class="align_center">94.1 ± 1.6</td><td class="align_center">96.2 ± 2.3</td></tr><tr class="table-tr"><td colspan="4"><hr class="tbody-hr"/></td></tr></table></td></tr></table>

<div>Recovery and repeatability of the proposed analytical method at three different spiking levels.</div>

International Journal of Analytical Chemistry

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Table 5

Table 5: Rapid and Sensitive Determination of Methylxanthines in Commercial Brands of Tea Using Ultra-High-Performance Liquid Chromatography-Mass Spectrometry 

Table 5 | Rapid and Sensitive Determination of Methylxanthines in Commercial Brands of Tea Using Ultra-High-Performance Liquid Chromatography-Mass Spectrometry 