ABL800 FLEX
Interference
Radiometer has experience in designing sensors that prevent fluctuations in results caused by interference and this is documented by various studies [1]. One of the major contributors to suppression of interference is a specially designed membrane that prevents interfering substances from getting to the electrode.
The Clinical Laboratory Standards Institute (CLSI) approved guideline for interference testing in clinical chemistry, EP7-A, Vol. 22, No. 27 [3] states:
”Manufacturers and other developers of laboratory methods are responsible for characterizing the analytical performance of their methods and analyzing hazards to patients caused by interfering substances. Manufacturers are required to provide information about interference susceptibility to those who use their systems.”
Sixty-two different endogenous and exogenous substances were identified and subjected to the interference test protocol EP-7A recommended by CLSI.
The test results proved that interference is suppressed: none of the 62 substances showed detectable signs of interference!
| Substance | Test concentration |
Interference (μmol/l) |
| Ascorbic acid | 227 µmol/L | < |8| |
| Acetoacetate | 10 mmol/L | < |8| |
| Acetone | 10 mmol/L | < |8| |
| Acetylsalicylic acid | 3.3 mmol/L | < |8| |
| Ammonia | 1 mmol/L | < |8| |
| Ampicillin | 152 µmol/L | < |8| |
| Beta-hydroxybutyrate | 10 mmol/L | < |8| |
| Bilirubin | 400 µmol/L | < |8| |
| Bleomycin sulfate | 45 mg/L | < |8| |
| Calcium chloride | 3 mmol/L | < |8| |
| Cephalexin | 337 µmol/L | < |8| |
| Cephalothin | 759 µmol/L | < |8| |
| Cefotaxime | 671 µmol/L | < |8| |
| Cefoxitin | 1.6 mmol/L | < |8| |
| Chlorpromazine | 6.3 µmol/L | < |8| |
| Creatine | 200 µmol/L | < |8| |
| Citrate | 50 mmol/L | < |8| |
| Cyclosporin | 12 µmol/L | < |8| |
| D(+)-Glucose | 60 mmol/L | < |8| |
| Dipyrone | 50 mg/L | < |8| |
| Dobutamine | 10 µg/L | < |8| |
| Dopamine | 5.9 µmol/L | < |8| |
| Doxycycline | 67.5 µmol/L | < |8| |
| Ethanol | 86.8 mmol/L | < |8| |
| Fluoride | 50 mmol/L | < |8| |
| Gentisic acid | 117 µmol/L | < |8| |
| Glutamate sodium salt | 2 g/L | < |8| |
| Glutathione – oxidized | 10 mg/L | < |8| |
| Glutathione – reduced | 10 mg/L | < |8| |
| HCO3– | 40 mmol/L | < |8| |
| Heparin (Li-salt) | 80000 U/L | < |8| |
| Hepes | 20 mmol/L | < |8| |
| Hemoglobin | 10 % hemolysis | < |8| |
| Hemoglobin | 3.5 % hemolysis | < |8| |
| Hydroxyurea | 100 µmol/L | < |8| |
| Ibuprofen | 2.4 mmol/L | < |8| |
| Intralipid | 5 % | < |8| |
| Intralipid | 2.5 % | < |8| |
| L-DOPA | 20 µmol/L | < |8| |
| L(+)-Glucose | 60 mmol/L | < |8| |
| Lithium nitrate | 3.2 mmol/L | < |8| |
| L-Lactic acid | 30 mmol/L | < |8| |
| L-Proline | 250 µmol/L | < |8| |
| Lidocaine hydrochloride | 100 µmol/L | < |8| |
| Lidocaine powder | 100 µmol/L | < |8| |
| 6-Mercapcenterurine | (13.1 mmol/L)* | < |8| |
| Magnesium nitrate | 3 mmol/L | < |8| |
| Methotrexate | 2.0 mmol/L | < |8| |
| Methyldopa | 71 µmol/L | < |8| |
| Oxo-(2)-butyric acid | 5 mmol/L | < |8| |
| Paracetamol (acetaminophen) | 1.7 mmol/L | < |8| |
| pH 8.0 | - | < |8| |
| pH 6.0 | - | < |8| |
| Phenylbutazone | 325 µmol/L | < |8| |
| Pyruvate | 3 mmol/L | < |8| |
| Rifampicin | 78.1 µmol/L | < |8| |
| Sarcosine | 1 µmol/L | < |8| |
| Sodium hydrogen carbonate | 40 mmol/L | < |8| |
| Sodium hydrogen phosphate | 2 mmol/L | < |8| |
| Theophyllin | 222 µmol/L | < |8| |
| Theophyllin acetic acid | 200 µmol/L | < |8| |
| Thiocyanate | 24 mmol/L | < |8| |
| Urea | 50 mmol/L | < |8| |
| Uric acid | 3 mmol/L | < |8| |
*Saturated stock solution
1. Kost,GJ, Nguyen,TH, Tang,Z. Whole-blood glucose and lactate. Arch Pathol Lab Med 2000; 124: 1128-34.
2. Myers GL, Miller WG, Coresh J et al. Recommendations for improving serum creatinine measurement: a report from the National Kidney Disease Education Program. Clin Chem 2006; 52: 5-18.
3. McEnroe RJ, Burrit MF, Powers DM et al. Interference testing in clinical chemistry; approved guideline. CLSI document EP7-A2 Vol 25, No 27. CLSI, 940 West Valley Road, Suite 1400, Wayne, Pennsylvania 19087-1898, USA, 2005.
