Dietary nicotine, as a source of nicotine biomarkers such as salivary cotinine, has been a controversial topic, mainly because of limited published data on nicotine in foods. Recently, a sample preparation method for nicotine in foods and an analytical method, based on gas chromatography with mass spectrometric detection, were developed and validated in our laboratory. Nicotine was determined in fresh, cooked and processed foods of the solanaceae family. In this study we have furthered this work to investigate the presence of cotinine in these vegetables, using GC–MS and HPLC-MS as independent alternative analytical techniques. A large number of samples was investigated, but cotinine was not detected in any of the samples, although very high sensitivity could be achieved. Based on the results, we report a monte carlo simulation of salivary cotinine levels obtained utilising dietary nicotine, food consumption data, and the variance in these parameters. In this estimate, a mean salivary cotinine concentration of 0.022 ng ml(-1) is predicted from dietary sources. This level is below the limit of detection for traditional analytical methods, but perhaps not for newly-developed methods.