Search

The aim of this paper is to quantify the levels of DDT and its main metabolites (DDE, DDD) and also of the HCH congeners in biological samples collected from birds living in the Lower Prut Floodplain Natural Park, Romania. In order to limit the stress on the bird species, a non-invasive approach was performed using chorioallantoic membrane of the eggs and feathers as representative samples. DDTs are the main organohalogen compounds in both categories of samples. Differences appear between species and categories of samples; for Anas sp. , the concentration is up to 10 times higher in eggshells than feathers. [ABSTRACT FROM AUTHOR]

The present paper describes the voltammetric behaviour and the quantitative determination of caffeic acid (CA) on a disposable pencil graphite electrode (PGE). The anodic peak current of CA recorded by differential pulse voltammetry (DPV) varies linearly with CA concentration in the range 1 × 10 −7 –3 × 10 −3 M. The detection and quantification limits were 8.83 × 10 −8 M and 2.94 × 10 −7 M caffeic acid, respectively. The mean recoveries of CA from Turkish green, white and black teas were 98.30%, 99.57% and 91.46%. For these three tea types the corresponding total polyphenolic contents (TPCs) evaluated by DPV on PGE were 35.81, 34.59 and 31.21 mg caffeic acid equivalent/g tea, respectively. These TPC values were in good accordance with those obtained by the Folin–Ciocalteu method. The developed DPV on PGE method constitutes a simple and inexpensive tool for the rapid assessment of TPC of tea samples. [ABSTRACT FROM AUTHOR]