PL
Metodą spektrometrii atomowo-absorpcyjnej oznaczono zawartość ołowiu, kadmu i niklu w dwudziestu rodzajach herbat (liściastych i granulowanych) oraz w naparach o średniej mocy sporządzonych z tych samych próbek. Dla ołowiu i niklu określono stopień ekstrakcji do fazy wodnej.
EN
Lead, cadmium and nickel contents were determined in leaf and granulated tea and tea infusions by atomic absorption spectroscopy using a Pye Unicam SP 192 apparatus and air-acetylene flame. Various grades of tea were obtained from several retail shops and wholesale companies in Lublin during 1995. Grades of tea grown in India, China and Sri Lanka (Ceylon) were tested. Lead, cadmiun and nickel were assayed using extraction technique after the metals had been complexed with APDC (ammonium pyrrolidine dithiocarbamate). MIBK (4-methyl-2-pentanone) saturated with redistilled water was used as the organic phase. Values of lead content in dry leaf and granulated tea ranged on the average between 0.445 ppm to 1.615 ppm. From 30.1% to 60.0% dry-product total lead were extracted to medium-strong tea infusions. Average cadmium concentrations of the test tea grades were 0.012 ppm to 0.047 ppm. Trace amounts of cadmium were extracted to the tea infusions of medium strenght. Nickel content in dry tea was high, on average from 2.98 ppm to 9.29 ppm, and the degree of extraction to the water phase was 41.6% to 82.2%. Lead content of some leaf and granulated tea grades was higher than the admissible value specified by Polish regulations.