Abstract:
Ceylon tea is famous throughout the world for its unique taste. Over 95 % tea produced in Sri
Lankais exported. In recent times many tea importing countries have either changed or in the
process of changing their food safety laws, generally resulting in lower limits for heavy
metals.Tea is generally regarded as safe (GRAS) and was not included in random monitoring
programmesat the point of entries to those countries in the past. However, recently in many
countriesGRAS food items are also subjected to the random monitoring process. Thus, it is
I
importantthat base line levels of heavy metals for different types of Sri Lankan black teas are
fe-establishedand precautionary measures are taken to ensure that Sri Lankan tea complywith
thesenew regulations. Heavy metals in black tea could change due to various factors and one
of the main factors is the Agro-ecological region they grow. There are eleven main Agroecologicalregions and the quality of the made tea produced is different trom region to region.
In thisstudy, an attempt was made to understand the natural level of heavy metals in black tea
producedin different Agro-ecological regions and their variation among regions. Further,
metalswere analysedto establishbase line values.
Thirtyfive factories were selected from different Agro-ecological regions of Sri Lanka. Black
tea (BOPgrade) was analysed for the heavy metals namely, copper, nickel, cadmium and iron.
Atomicabsorption spectrophotometry was used as the analytical technique to analyse the
metal content in black tea. AOAC Official Methods of Analysis were followed as the
analyzingprocedure. Further, compliance of the sample with ISO 3720, specifications for
blacktea was also verified.
Copper content in black tea was well below the Sri Lankan Limit of 100 ppm in all regions. It
wasfound tha t copper content was below 40 ppm. Nickel content in black tea was below 8
ppmin all regions. Cadmium content was below 0.2 ppm. The current Sri Lankan Standard is
also0.2 ppm. Iron content in black tea was well below the Sri Lankan Limit of 500 ppm. It
wasfoundthat iron content was below 300 ppm. Copper, nickel and cadmium content in black
tea did not significantlychanged with Agro-ecological region. However, iron content in black
teahas a significantvariation within Agro-ecologicalregions.
