Differentiation of eight tea (Camellia sinensis) cultivars in China by elemental fingerprint of their leaves

Abstract

BACKGROUND: Tea is an infusion made from dried leaves of tea (Camellia sinensis) and can be a good dietary source of essential trace metals for humans. Therefore, it is necessary to consider variations in element content of tea leaves among tea cultivars. Thus, elemental fingerprint techniques, based on elemental contents (Al, B, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, P, Pb, and Zn) determined by inductively coupled plasma atomic emission spectrometry (ICP-AES) and multivariate statistical analysis, have been used to differentiate eight tea cultivars.

Simple and Fast Sample Preparation Procedure Prior to Multi-element Analysis of Slim Teas by ICP OES

“…Results for Mn presented in our study are generally comparable to those reported by Chen et al (2009), Colak et al (2005, Dash et al (2008), Narin et al (2004a, Malik et al (2008), McKenzie et al (2010) and Nookabkaew et al (2006). Concentrations of Fe in slim teas are very similar to those obtained by Aksuner et al (2012), Colak et al (2005), Kara (2009) andMcKenzie et al (2010), but higher than those determined by Chen et al (2009), Matsuura et al (2001 and Narin et al (2004b). Contents of Zn found in this work are consistent with the findings of Matsuura et al (2001) and Xie et al (1998).…”

“…Narin et al (2004b) established that the concentration of Zn in black tea produced in Turkey was within the range of 110-146 μg g −1 . In the case of Cu, our results are close to values found in teas by Aksuner et al (2012), Chen et al (2009), Colak et al (2005, Kara (2009) and Soylak et al (2007) and are significantly lower than those reported by Malik et al (2008) and Salahinejad and Aflaki (2010).…”

“…In general, Ca, Mg and P are the major mineral constituents of slim teas. Concentrations of (Chen et al 2009;Malik et al 2008;Nookabkaew et al 2006;Szymczycha-Madeja et al 2013), indicating that the aforementioned elements are the most abundant in many herbal medicines and teas. Teas and herbs can be an important source of such essential elements as Mn, Fe, Zn and Cu, which are crucial for biochemical reactions in the human body.…”

“…Generally, the determination of total concentrations of various macro-and micro-elements in different teas as well as medicinal plants is carried out with the use of flame atomic absorption spectrometry (FAAS) (Aksuner et al 2012;Colak et al 2005;Kumar et al 2005;Li et al 2006;Malik et al 2008;Narin et al 2004a,b;Seenivasan et al 2008;Soylak et al 2007), graphite furnace atomic absorption spectrometry (GF AAS) (Dash et al 2008;Seenivasan et al 2008), inductively coupled plasma optical emission spectrometry (ICP OES) (Chen et al 2009;Dash et al 2008;Kara 2009;Malik et al 2008;Matsuura et al 2001;McKenzie et al 2010;Mierzwa et al 1998;Özcan et al 2008), inductively coupled plasma mass spectrometry (ICP MS) (Kara 2009;Matsuura et al 2001;Nookabkaew et al 2006;Shen and Chen 2008) and X-ray fluorescence spectrometry (XRFS) (Salvador et al 2002;Xie et al 1998). As a rule, the decomposition of the matrix of tea samples is an indispensable and mandatory step before their elemental analysis by the majority of these spectrometric methods.…”

“…Typically, the digestion is carried out by a conventional hot-plate or microwave-assisted heating of tea samples with oxidizing reagents, including HNO 3 , HNO 3 + H 2 O 2 , HNO 3 +H 2 SO 4 +H 2 O 2, HNO 3 +H 2 O 2 +HF, HNO 3 + HClO 4 , HNO 3 + HCl, HNO 3 + HCl + HF, (Aksuner et al 2012;Colak et al 2005;Kumar et al 2005;Narin et al 2004a,b;Dash et al 2008;Matsuura et al 2001;McKenzie et al 2010;Mierzwa et al 1998;Nookabkaew et al 2006;Salahinejad and Aflaki 2010;Shen and Chen 2008;Soylak et al 2007). Except for the mentioned wet ashing procedures, dry-ashing procedures, as described by the Association of Analytical Chemistry (Seenivasan et al 2008) or modifications of this official method (Chen et al 2009;Li et al 2006;Malik et al 2008;Narin et al 2004b), are also used at the stage of the sample preparation of tea before its spectrochemical analysis.…”