Due to the knowledge of the rotation period and the presence of a rather strong surface magnetic field , the sharp-lined young Herbig Ae star HD 101412 with a rotation period of 42 d has become one of the most well-studied targets among the Herbig Ae stars . High-resolution HARPS polarimetric spectra of HD 101412 were recently obtained on seven different epochs . Our study of the spectral variability over the part of the rotation cycle covered by HARPS observations reveals that the line profiles of the elements Mg , Si , Ca , Ti , Cr , Mn , Fe , and Sr are clearly variable while He exhibits variability that is opposite to the behaviour of the other elements studied . Since classical Ap stars usually show a relationship between the magnetic field geometry and the distribution of element spots , we used in our magnetic field measurements different line samples belonging to the three elements with the most numerous spectral lines , Ti , Cr , and Fe . Over the time interval covered by the available spectra , the longitudinal magnetic field changes sign from negative to positive polarity . The distribution of field values obtained using Ti , Cr , and Fe lines is , however , completely different compared to the magnetic field values determined in previous low-resolution FORS 2 measurements , where hydrogen Balmer lines are the main contributors to the magnetic field measurements , indicating the presence of concentration of the studied iron-peak elements in the region of the magnetic equator . Further , we discuss the potential role of contamination by the surrounding warm circumstellar matter in the appearance of Zeeman features obtained using Ti lines .