<abstract xmlns="http://www.w3.org/1999/xhtml"><p>Introduction: Camellia sinensis, a widely used plant, optimally grows in a low pH soil that in most cases contains high amounts of aluminum. Objectives: The aluminum content of the tea obtained from Camellia sinensis and other plants was compared. The influence of pH on the aluminum content of the tea was also measured. Materials and methods: The aluminum content of 48 samples was measured using a colorimetric method. The method is based on the ability of aluminum to form a stable complex with xylenol orange at low pH; this complex has an absorption maximum of 555 nm. Results: The method was validated for tea obtained with water and for tea obtained with water containing citric acid. The method proved linear over the rage of 0.7 – 7 ug/ml, coefficient of variation ranged between 2.6 – 7.68% (was dependent on the pH of the solution used to obtain the tea), accuracy was suitable for quantitative measurement (92.39-102.92%) and the complex proved to be stable for at least 1 hour. The following concentrations were measured: green tea (1.59 - 7.70 µg/ml), black tea (1.39 - 5.60 µg/ml), fruit tea (1.01 - 5.63 µg/ml) and herbal tea (1.03 - 5.24 µg/ml). Conclusion: The method proved useful and easily applicable for screening aluminum content of plants used for tea brewing. Camellia sinensis both green and black types had significantly higher aluminum contents than other type of teas. Adding citric acid, as would result from use of lemon juice, significantly increased the aluminum extraction from the plants used for tea brewing.</p></abstract>

Introduction: Camellia sinensis, a widely used plant, optimally grows in a low pH soil that in most cases contains high amounts of aluminum. Objectives: The aluminum content of the tea obtained from Camellia sinensis and other plants was compared. The influence of pH on the aluminum content of the tea was also measured. Materials and methods: The aluminum content of 48 samples was measured using a colorimetric method. The method is based on the ability of aluminum to form a stable complex with xylenol orange at low pH; this complex has an absorption maximum of 555 nm. Results: The method was validated for tea obtained with water and for tea obtained with water containing citric acid. The method proved linear over the rage of 0.7 – 7 ug/ml, coefficient of variation ranged between 2.6 – 7.68% (was dependent on the pH of the solution used to obtain the tea), accuracy was suitable for quantitative measurement (92.39-102.92%) and the complex proved to be stable for at least 1 hour. The following concentrations were measured: green tea (1.59 - 7.70 µg/ml), black tea (1.39 - 5.60 µg/ml), fruit tea (1.01 - 5.63 µg/ml) and herbal tea (1.03 - 5.24 µg/ml). Conclusion: The method proved useful and easily applicable for screening aluminum content of plants used for tea brewing. Camellia sinensis both green and black types had significantly higher aluminum contents than other type of teas. Adding citric acid, as would result from use of lemon juice, significantly increased the aluminum extraction from the plants used for tea brewing.

Aluminium contamination of several types of tea

University of Medicine, Pharmacy, Sciences and Technology of Tîrgu Mureş

Faculty of Pharmacy, Department of Toxicology and Biopharmacy

Bulletin of Medical Sciences

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

{"article-title":"Aluminium contamination of several types of tea"}

Introduction: Camellia sinensis, a widely used plant, optimally grows in a low pH soil that in most cases contains high amounts of aluminum. Objectives: The...

Aluminium contamination of several types of tea

Publié en ligne: 13 févr. 2020

Pages: 42 - 46

Reçu: 27 févr. 2019

Accepté: 02 avr. 2019

DOI: https://doi.org/10.2478/orvtudert-2019-0003

Mots clés
tea, aluminum, colorimetric method, citric acid

© 2019 Fogarasi Erzsébet et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Aluminium contamination of several types of tea

Publié en ligne: 13 févr. 2020

Pages: 42 - 46

Reçu: 27 févr. 2019

Accepté: 02 avr. 2019

DOI: https://doi.org/10.2478/orvtudert-2019-0003

Mots cléstea, aluminum, colorimetric method, citric acid

© 2019 Fogarasi Erzsébet et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Mots clés
tea, aluminum, colorimetric method, citric acid