Interference Due to Haemolysis in Routine Photometric Analysis—A Survey

Abstract

To assess the affect of haemolysis on routine photometric methods used by participants in the Irish External Quality Assessment Scheme for Clinical Biochemistry (IEQAS) a sample was distributed with a supplied diluent containing haemoglobin. A sample of the same batch had previously been circulated as a normal distribution. Many analytes/methods were affected by the haemolysis. The range of values reported for each analyte was as follows. Albumin 34-48 g/L (baseline 37 g/L). Calcium 2.16-2.68 mmol/L (baseline 2.34 mmol/L). Urate 90-470 mumol/L (baseline 195 mumol/L). Creatinine 55-161 mumol/L (baseline 140 mumol/L). Glucose 4.1-5.6 mmol/L (baseline 4.8 mmol/L). Bilirubin 14-60 mumol/L (baseline 36 mumol/L). Urea 3.4-7.3 mmol/L (baseline 3.8 mmol/L). Iron 17.9-55.0 mumol/L (baseline 26.8 mumol/L). Inorganic phosphorus 0.22-2.41 mmol/L (baseline 1.59 mmol/L). Cholesterol 3.0-5.9 mmol/L (baseline 4.1 mmol/L). In some situations the use of an appropriate blank may solve the problem, but it must be remembered that interference caused by haemoglobin may be more complex than merely spectral.