The interference of severe lipid turbidity to sodium, potassium and chloride in serum tested by indirect ion selective electrode
NI Li1, FANG Mao2, ZHU Lidan1, GE Haifeng1, XU Xiaojie1, DING Hongxiang1
1.Department of Laboratory Mdeicine, the Second Affiliated Hospital of Wenzhou Medical University, Wenzhou 325027, China; 2.Department of Laboratory Medicine, Maternal and Child Health Hospital of Yuyao, Ningbo 315400, China
NI Li,FANG Mao,ZHU Lidan, et al. The interference of severe lipid turbidity to sodium, potassium and chloride in serum tested by indirect ion selective electrode[J]. JOURNAL OF WEZHOU MEDICAL UNIVERSITY, 2019, 49(11): 802-806.
Abstract：Objective: To study the interference of severe lipid turbidity to sodium, potassium and chloride in serum tested by indirect ion selective electrode method. Methods: According to EP7-A2 and EP9-A2, sodium, potassium and chloride in serum of 40 samples without lipid turbidity from inpatients admitted to the Second Affiliated Hospital of Wenzhou Medical University were measured by indirect ion selective electrode method (SIEMENS ADVIA 2400 automatic biochemical analyzer) and direct ion selective electrode method (Johnson VITROS 5600 dry chemical analyzer ). Another 40 samples with different lipid turbidity index from the same hospital were tested by the two methods. Samples of 3 different levels of sodium, potassium and chloride were collected for interference tests. Results: There were no obvious differences between the sodium, potassium and chloride in serum of 40 samples without lipid turbidity tested by indirect ion selective electrode method and those tested by direct ion selective electrode method (P>0.05). When triglyceride was greater than 35.3 mmol/L and turbidity index was greater than 965, interference test in vitro revealed that there was significant negative interference to sodium of 113 mmol/L in serum tested by indirect ion selective electrode method (bias>-2%). When triglyceride was greater than 28.4 mmol/L and turbidity index was greater than 710, there was significant negative interference to potassium of 5.8 mmol/L in serum tested by indirect ion selective electrode method (bias>-3%). When triglyceride was greater than 20 mmol/L and turbidity index was greater than 615, there was significant negative interference to chloride of 79.6 in serum tested by indirect ion selective electrode method (bias>-2.5%). Conclusion: There are negative interferences to sodium, potassium and chloride in serum with lipid turbidity tested by indirect ion selective electrode method. Sodium, potassium and chloride in serum with severe lipid turbidity should be measured by direct ion selective electrode method or measured by indirect ion selective electrode method after removing the lipid by high speed centrifugation.
