Application of Solid Phase Extraction on Multiwalled Carbon

Abstract: A novel and highly sensitive method for the determination of some heavy

metals in skin whitening cosmetics creams using multiwalled carbon nanotubes MWCNTs

as solid phase extraction sorbent for the preconcentration of these heavy metals prior to

their determination by inductively coupled plasma atomic emission spectrometry is

described. Different practical parameters have been thoroughly investigated and the

optimum experimental conditions were employed. The developed method was then applied

for the determination of arsenic, bismuth, cadmium, mercury, lead and titanium in samples

of skin whitening cosmetics. The detection limits under these conditions for As, Bi, Cd, Pb,

Hg and Ti were 2.4, 4.08, 0.3, 2.1, 1.8, and 1.8 ng·mL−1, respectively. The relative standard

deviations (RSDs) were found to be less than 2.0%. For validation, a certified reference

material of NIST SRM 1570a spinach leaves was analyzed and the determined values were

in good agreement with the certified values. The recoveries for spiked samples were found

to be in the range of 89.6–104.4%.

كمال الدين عمر احمد محمد