Blood collection tubes: an aspect of preanalytical variations of copper and zinc analyses

Blood collection devices are essential for specimen quality. The aim of the present study is to examine the applicability of newly produced Barricor LH tubes for copper (Cu) and zinc (Zn) in view of influence due to tube additives and components. Comparison to already existing tubes for trace elements is made.
Blood is drawn from 32 volunteers into 3 types BD tubes: Barricor LH (REF 365032), K2EDTA (REF 368381) and Trace element (TE) serum (REF 368380). Cu and Zn concentrations are measured by flame atomic absorption using AAnalyst 400, Perkin Elmer.
Statistically significant differences between Cu results exist depending on tube type (P<0.001). Median (IQR) perceived effort levels for the K2EDTA, Barricor LH and TE tubes running trial are 19.06 (14.76 to 31.59), 19.43 (4.76 to 31.96) and 19.34 (15.01 to 35.23), respectively. Analysis points no statistically significant differences between mean Zn levels for three types of tubes (P=0.753). Median (IQR) perceived effort levels for the K2EDTA, Barricor LH and TE tubes running trial are 10.74 (3.06 to 15.45), 10.25 (2.91 to 14.38) and 10.71 (2.91 to 16.14), respectively. Very strong correlation between the results in three types of tubes for both elements is established: Cu (R>0.991) and Zn (R>0.851).
Cu and Zn results for Barricor LH plasma tubes are comparable to those, designed for trace analysis: K2EDTA plasma and TE serum. It could be recommended for each laboratory to test the preferred blood collected tubes for determination of Cu and Zn especially when low concentrations have been suspected.