Context. High mass stars form in groups or clusters in dense molecular clumps with sizes of 1 pc and masses of 200 M _⊙ . Infrared-dark clumps and the individual cores within them with sizes < 0.1 pc and masses < 100 M _⊙ are important laboratories for high-mass star formation in order to study the initial conditions.

Aims. We investigate the physical and chemical properties of high-mass clumps in order to better understand the early evolutionary stages and find targets that show star formation signs such as infall motions or outflows.

Methods. We selected the high-mass clumps from ATLASGAL survey that were identified as dark at 8/24 μ m wavelengths. We used MALT90 Survey data which provides a molecular line set (HCO ⁺ , HNC, HCN, N ₂ H ⁺ , H ¹³ CO ⁺ , HN ¹³ C, SiO) to investigate the physical and chemical conditions in early stages of star formation.

Results. Eleven sources have significant SiO detection (over 3 σ ) which usually indicates outflow activity. Thirteen sources are found with blue profiles in both or either HCO ⁺ and/or HNC lines and clump mass infall rates are estimated to be in the range of 0.2 × 10 ⁻³ M _⊙ yr ⁻¹  − 1.8 × 10 ⁻² M _⊙ yr ⁻¹ . The excitation temperature is obtained as < 24 K for all sources. The column densities for optically thin lines of H ¹³ CO ⁺ and HN ¹³ C are in the range of 0.4–8.8 (×10 ¹² ) cm ⁻² , and 0.9–11.9 (×10 ¹² ) cm ⁻² , respectively, while it is in the range of 0.1–7.5 (×10 ¹⁴ ) cm ⁻² for HCO ⁺ and HNC lines. The column densities for N ₂ H ⁺ were ranging between 4.4–275.7 (×10 ¹² ) cm ⁻² as expected from cold dense regions. Large line widths of N ₂ H ⁺ might indicate turbulence and large line widths of HCO ⁺ , HNC, and SiO indicate outflow activities. Mean optical depths are 20.32, and 23.19 for optically thick HCO ⁺ and HCN lines, and 0.39 and 0.45 for their optically thin isotopologues H ¹³ CO ⁺ and HN ¹³ C, respectively.

Conclusions. This study reveals the physical and chemical properties of 30 high-mass IR-dark clumps and the interesting targets among them based on their emission line morphology and kinematics.