Specific and robust ion chromatographic determination of hypothiocyanite in saliva samples
The enzymatic system in saliva, consisting of salivary peroxidase (SPO), hydrogen peroxide (H2O2), and thiocyanate (SCN−), produces hypothiocyanite (OSCN−) as a high effective antibacterial compound. OSCN− is of great importance for the natural non-specific antibacterial resistance in the oral cavity. However, no analytical method currently exists to selectively quantify OSCN− in saliva samples. A robust and specific analytical method for the determination of OSCN− was developed based on ion chromatography with combined UV and electrochemical detection. Calibration was achieved by calculating a derived calibration factor based on the known ratio of molar extinction coefficients of SCN− and OSCN−. Thus, the specific quantification of OSCN− in saliva samples is possible, as demonstrated here. The median value of 200 saliva samples was determined to be 0.56 mg L−1 (median), with a maximum of 3.9 mg L−1; the minimum value was below the detection limit (< 0.09 mg L−1). The recovery rate in individual saliva samples was 95 ± 8%.
KeywordsHypothiocyanite Thiocyanate Ion chromatography Saliva peroxidase
The study was supported by the European Regional Development Fund: V-630-S-137-2012/024, V-630-F-137-2012/023, V-630-VB243-2012/022 (Mecklenburg-Western Pomerania Ministry for Economics, Employment and Tourism/Bmp Bulk Medicines & Pharmaceuticals Production GmbH) and by University Medicine Greifswald.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflicts of interest.
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