Investigation of the heavy metal contents of commercially available tea

• Main Authors: Li, Jian-Zhang, 李健彰
• Other Authors: Duh, Ming-Chin
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/766bvm

碩士 === 國立清華大學 === 應用科學系所 === 106 === According to the market selling twenty-six kinds of tea through the aqua regia digestion , microwave digestion and infusion pretreatment . The tea was classified as five categories: non-fermented tea, partially fermented tea, completely fermented tea, Herbal tea and others.the metal contents (Zn , Ni , Cd , Mn , Pb , Cu , Co and Cr) of tea prepared solution were analyzed by using （Inductively Coupled Plasma Optical Emission Spectrometry) ICP-OES . The concentration of aqua regia digestion pretreatment sample were in the range of Zn: 8.2 ~ 53.3ppm、Ni: N.D ~ 16.5 ppm、Mn: 45.7 ~ 1403 ppm、Cu: N.D ~ 22.9 ppm and Cr: N.D ~ 5.5 ppm; The concentration of microwave digestion pretreatment sample were in the range of Zn: 10.5 ~ 58.8 ppm、Ni: N.D ~ 16.6 ppm、Mn: 47.4 ~ 1492 ppm、Cu: N.D ~ 23.2 ppm and Cr: N.D ~ 6.4 ppm; The concentration of infusion pretreatment sample were in the range of Zn: 4.0 ~ 29.9 ppm、Ni: N.D ~ 15.7 ppm及Mn: 24.9 ~ 958 ppm. The metal Cd , Pb and Co was not detected by two digestion pretreatment ,and other metal by infusion extract , Cu and Cr was not detected.