Authors:Wei Fan, Yongde Yue, Feng Tang, Haiqun Cao, Jing Wang, and Xi Yao
A high-performance thin-layer chromatographic (HPTLC) method for simultaneous analysis of temephos and fenitrothion in green tea has been established and validated. The sample was extracted with ethyl acetate by mechanical vibration at room temperature and the extract was cleaned by use of an SPE tandem column, before elution with dichloromethane. The extract was applied as bands to glassbacked silica gel 60F254 HPTLC plates. The plates were developed with acetone-hexane 3+7 (v/v), in an unsaturated glass twin-trough chamber. The developed HPTLC plates were evaluated densitometrically. The detection limits of temephos (RF 0.55) and fenitrothion (RF 0.69) were 20 and 10 ng, respectively. Recovery from green tea of the two pesticides at levels of 0.2 to 4 mg kg−1 was 80–107% with relative standard deviations of 4.4–20.2%. The precision and accuracy of the method were generally fit for analysis of temephos and fenitrothion residues in green tea.
Authors:Zsanett Bodor, Bianka Pergel, and Csilla Benedek
., 2018; Gardner et al., 2007 ). The bioactive compounds in greenteas are mainly flavan-3-ols (catechins), proanthocyanidins (tannins) and flavonols, while black tea contains theaflavins and thearubigins ( Malongane et al., 2017 ). Lemon and honey are
Authors:D. Das, S. Tamuly, M. Das Purkayastha, B. Dutta, C. Barman, D.J. Kalita, R. Boro, and S. Agarwal
1 Introduction With a long-established tradition of consumption in China, India, and East Asia, greentea ( Camellia sinensis ) is one of the most lauded food commodities for its gamut of health benefits. Its array of beneficial properties is
Authors:Mingyu Zhao, Ercheng Zhao, Junxue Wu, Yuqi Li, and Baotong Li
5 min to remove bubbles. The hydrophobic deep eutectic solvents (h-DESs) was successfully synthesized after cooling to the room temperature. Analytical method Packaged orange juice and greentea were purchased from local supermarket (Beijing, China
In some tea tree planting areas within 300 km from the TEPCO’s Fukushima Daiichi Nuclear Power Plant (FNPP), it was found
that newly emerged tea plant leaves for green tea contained two radiocesium species (cesium-134 and cesium-137). In this study,
using processed green tea leaves for drinking, extraction ratios of radiocesium under several brew conditions were observed.
When 90 °C water was used, 50–70% of radiocesium was extracted into the water, while 54–60% of radiocesium was extracted with
60 °C water. A part of radiocesium would be removed from leaves if the leaves were washed with 20 and 60 °C water before brewing,
and the efficiencies were 11 and 32%, respectively. Newly emerged camellia leaves were used to simulate the radiocesium removal
ratio from raw tea leaves by washing and boiling; radioactivity concentration was decreased to 60% of the original concentration
with washing and 10 min boiling. From these results, it was found that almost half of the radiocesium would not be removed
from raw or processed tea leaves. The values obtained in the present study could be used for internal radiation dose estimation
from tea leaves.