To evaluate the effect of sample type, storage time and temperature on serum potassium detection.

The 12 cases in the physical examinations in hospital from May 2017 to June 2017 were selected and their blood were collected under quiet and empty stomach. The separate blood specimens were collected from contains glue and heparin anticoagulant sample tube, centrifugal separation of serum and plasma after respectively at 4 ℃, 20 ℃, 70 ℃ refrigerator storage. Repeated measurement of serum potassium was conducted three times at 8 time points: 1 h, 3 h, 6 h, 24 h, 48 h, 72 h, 1 w and 2 w. The variation trend of serum potassium content with time and temperature in different sample containers was analyzed.

Two kinds of sample tube of potassium determination results in constant temperature, the measured value with the extension of time showed a trend of slow decline and heparin tube decline significantly, the difference was statistically significant (4 ℃ F value of 17.42, P<0.05). The plasma potassium level was acceptable within 1 h of the 4 degree refrigerator, and the <6% was acceptable at -20 ℃ and -70 ℃ for 3 h. Serum potassium bias <6% in serum 72 h at 4 ℃, -20 ℃ and -70 ℃ was acceptable; There was no significant difference in blood potassium detection between two specimen types (P>0.05).

Both heparin sodium tube and separation rubber tube can be used to detect serum potassium level, the stability of serum potassium tube is better than that of heparin sodium tube, and heparin sodium tube is better than that of separation rubber tube in emergency detection. Each laboratory shall evaluate the type and storage conditions of serum potassium test samples in the laboratory.

Potassium; Plasma; Serum; Temperature; Time