Development of a Simple and Accurate Spectrophotometric Method for the Determination of Trace Levels of Cu, Zn and Pb in Adult Egyptian Blood Samples Using (1,5-Diphenylthiocarbazone)

Abstract

Aims: Development of a simple and accurate spectrophotometric method for the determination of Cu, Zn and Pb in adult Egyptians’ blood, plasma and serum using dithizone. Place of Study:  Hematology Laboratory, Armed Forces Laboratories for Medical Research and Blood Bank, Kobry El-Kobba, Cairo, Egypt. Methodology:  100 blood samples from adults frequenting the Hematology Lab services were randomly obtained.  The tested group comprised 57 males aging from 22 to 55 years and 43 females aging from 27 to 57 years.  Three methods: Ready-to-use Kit (Reference method), ICP-MS (validation method) and Dithizone spectrophotometric method were used to determine Cu, Zn and Pb levels in these samples. Results: The results for the proposed dithizone revealed that the Cu levels were higher than those obtained for Zn content.  As for the per gender levels, the Cu concentration range was (60 -148.11 µg/dL) for males and for females, it was (60.71-159.19 µg/dL).  The measured Zn levels for males ranged between 72.2-132.83 µg/dL but for females, it was between 55.95 – 123.62 µg/dL.  Pb levels obtained ranged from 0 - 25.8 µg/dL and the results showed no gender distinction.  The proposed method was validated and showed a linear regression coefficient (R2) above 0.99 for all elements.  The limit of detection (LOD) for the developed method was 4.47, 4.37 and 3.97 µg/dL for Cu, Zn and Pb, respectively.  As well, the limit of quantification (LOQ) was 13.55, 13.25 and 12.03 µg/dL for Cu, Zn and Pb respectively. The modality of the data obtained was tested statistically. Conclusion: The developed method provided wider calibration and working ranges for Cu, Zn and Pb in the tested blood samples than that reported for the reference and validation methods.  The higher levels of Cu and Zn may be linked to dietary/nutrition intake while Pb content may be more linked to anthropogenic exposure.