The levels of some selected essential, non-essential, toxic elements and water-soluble inorganic anions (WSIAs) leached from green tea (GT) leaves infusion in boiled water at various time breaks were determined. A number of 29 GT samples were analyzed by Inductively Coupled Plasma-Mass/optical emission Spectrometry (ICP-OES/MS) and Ion chromatography (IC). The levels of studied elements and WSIAs (F⁻, Cl⁻, NO₃⁻, PO₄³⁻ and SO₄²⁻) leached from GT leaves in boiled water increased on growing infusion time. Chemical speciation (labile and complexed fractions) of P, Al, Cu, Pb and Cd in GT leaves in boiled water was estimated. At 95% confidence level (P > 0.50), the student t-test values as calculated for essential and toxic metals were smaller than the critical value indicating no significant differences between element concentrations in the tested samples. The average daily dietary intake (ADDIs) for selected elements and the average daily intake (ADI) and the chronic reference dose (RFD) for Cd (μg kg⁻¹ BW day⁻¹) were critically determined. Evaluation of inorganic composition allows quantification of the leaching percentage and the hazard beyond provisional acceptable average daily intake (ADI) values.

Practical applications

WSIAs plays a significant role in green tea quality monitoring. Calculation and speciation of the mineral configuration and selected elements of GTs is of prime importance to evaluate the intake of hazard metals and biocomponent associated with the eating of infusions. Therefore, the levels of WSIAs leached in boiled tea infusions using IC and ICP-OES/MS were determined. However, the number of GT samples and their origins are limited. The work clearly indicated that, the differentiation and classification of tea samples from various provinces in many countries could be possible employing pattern recognition and analytical techniques. The levels of the elements K, P, Si, Fe, Cu, Al, Pb and Cd may be used as appropriate descriptors for identification of GTs origin.

中文翻译：

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绿茶中微量元素的痕量测定和形态分析

确定了在不同的时间间隔从绿茶（GT）叶浸入开水后浸出的一些必需的，非必需的，有毒的元素和水溶性无机阴离子（WSIAs）的水平。通过电感耦合等离子体质谱/光发射光谱法（ICP-OES / MS）和离子色谱法（IC）分析了29个GT样品。研究的元素和WSIAs水平（F ^- ，氯^-，NO ₃ ^-，PO ₄ ^3-和SO ₄ ^2-）的开水从GT叶浸出增加上生长滴注时间。估算了白开水中GT叶片中P，Al，Cu，Pb和Cd的化学形态（不稳定和复杂的组分）。在95％置信水平下（P > 0.50），对于必需和有毒金属计算的学生t-检验值小于临界值，表明被测样品中元素浓度之间无显着差异。严格确定选定元素的平均每日饮食摄入量（ADDIs）和Cd（μgkg ^-1 BW day ^-1）的平均每日摄入量（ADI）和慢性参考剂量（RFD）。评估无机成分可以对浸出百分比和危害进行定量，超出临时可接受的平均日摄入量（ADI）值。

实际应用

WSIA在绿茶质量监测中起着重要作用。GTs的矿物构型和选定元素的计算和形成对于评估摄入有害物质的有害金属和生物成分的摄入至关重要。因此，确定了使用IC和ICP-OES / MS在煮沸茶浸液中浸出的WSIAs的水平。但是，GT样本的数量及其来源是有限的。这项工作清楚地表明，利用模式识别和分析技术，可以对许多国家不同省份的茶样品进行分类和分类。元素K，P，Si，Fe，Cu，Al，Pb和Cd的水平可用作识别GTs来源的适当描述符。