Detection of potential chronic kidney disease markers in breath using gas chromatography with mass-spectral detection coupled with thermal desorption method

The analytical potential of chromatographic breath analysis towards detection of compounds suggested as markers of chronic kidney disease (CKD) was tested. Until now, trimethylamine (TMA) considered as a potential marker of renal disorder was detected mainly in plasma. Detection of TMA in breath was rarely undertaken due to analytical difficulties associated with amines’ properties. The results of our investigations confirmed that an application of thermal desorption (TD) and gas chromatography with mass-spectral detection (GC/MS) allows direct detection of TMA in breath. The preliminary studies allowed to determine the breath composition in case of patients suffering from CKD and to compare the obtained results to a control group. Breath samples were collected from 14 patients and 9 healthy volunteers. TMA was detected in all patients suffering from CKD in the range 1.76–38.02 ppb, but not in the control group. Acetone and isoprene were present in the exhaled air of all examined persons. The concentration of acetone was in the range of 26.52–329.46 ppb in the patient group and 73.11–437.14 ppb in the control group. Isoprene was detected in the range 57.17–329.8 ppb among CKD patients and 27.99–143.77 ppb in healthy volunteers. Additionally aliphatic hydrocarbons and sulfur compounds were determined in breath as compounds which could be essential in case of diseases coexisting with CKD. Apart from TMA and pentane no statistically significant differences were found using our analytical technique. TMA was detected in the breath of all patients with CKD and in none of breath samples in control group. TMA seems to be a promising marker of CKD.