Ultrasonic oscillation dialysis-graphite furnace atomic absorption spectrometer method for determination of "free" copper and exchangeable copper in serum.
BACKGROUND
The determination of copper (Cu) in human blood is important in medical diagnosis. However, its biological activities strongly depend on the chemical forms, and thus data for total Cu concentration is not sufficient for medical diagnosis or mechanism study. Therefore, analyses of copper species in serum have much more physiologically meaningful.


METHODS
Ultrasonic oscillation dialysis procedure was introduced in the determination of "free" Cu, more precisely PBS dialysis Cu (DiaCu), and exchangeable Cu (EXCu) by graphite furnace atomic absorption spectrometry (GFAAS). Then the levels of serum "free" Cu and EXCu from hepatitis, liver cancer, and cervical cancer patients were determined.


RESULTS
The accuracy of the method ranged from 92% - 97% for PBS DiaCu and 90% - 107% for EXCu when using a dialysis membrane pore size of 25 kDa. The regression equation of the calibration curve was expressed as y = bChi + a, with linear regression coefficients (r2) of 0.9999 for ultrapure water and 0.9998 for PBS buffer and EDTA buffer. The limit of detection is 0.76 microg/L. Application of this method to serum samples showed that the levels of"free" Cu and EXCu in serum changed in various pathophysiological conditions.


CONCLUSIONS
Ultrasonic oscillation dialysis-GFAAS method described here for the speciation of "free" Cu and EXCu in serum is simple with good reproducibility and small sample volume.
Yuan
Y
Zhang
Yaowen
Y
Chen
Zhexuan
Z
Lin
Qi
Q
Li
Yichang
Y
Chen
Lin
L
Peng
Ming
M
Han
D000328:Adult; D001774:Blood Chemical Analysis / Q000379:methods*; D003300:Copper / Q000097:blood*; D003956:Dialysis; D005260:Female; D006505:Hepatitis / Q000097:blood; D006801:Humans; D008113:Liver Neoplasms / Q000097:blood; D008875:Middle Aged; D013054:Spectrophotometry, Atomic; D014462:Ultrafiltration; D014465:Ultrasonics; D002583:Uterine Cervical Neoplasms / Q000097:blood
D003300:Copper