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High mass stars form in groups or clusters within massive cores in densemolecular clumps with sizes of 1pc and masses of 200Msun which are importantlaboratories for high-mass star formation in order to study the initialconditions. We investigate the physical and chemical properties of high-massclumps in order to better understand the early evolutionary stages and findtargets that show star formation signs. We selected the high-mass clumps fromATLASGAL survey that were identified as dark at 8/24$\mu$m wavelengths and usedMALT90 data which provides a molecular line set to investigate the physical andchemical conditions in early evolutionary stages. Eleven sources havesignificant SiO detection (over 3$\sigma$) which usually indicates outflowactivities. Thirteen sources are found with blue profiles in both or eitherHCO$^+$ and/or HNC lines and clump mass infall rates are estimated to be in therange of 0.2E+3 Msunyr$^{-1}$ $-$ 1.8E-2 Msunyr$^{-1}$. The excitationtemperature is obtained as <24K for all sources. The column densities foroptically thin lines of H$^{13}$CO$^{+}$ and HN$^{13}$C are in the range of0.4-8.8(E+12) cm$^{-2}$, and 0.9-11.9(E+12) cm$^{-2}$, respectively, while itis in the range of 0.1-7.5(E+14) cm$^{-2}$ for HCO$^{+}$ and HNC lines. Thecolumn densities for N$_{2}$H$^{+}$ were ranging between 4.4-275.7(E+12)cm$^{-2}$ as expected from cold dense regions. Large line widths ofN$_{2}$H$^{+}$ might indicate turbulence and large line widths of HCO$^{+}$,HNC, and SiO indicate outflow activities. Mean optical depths are 20.32, and23.19 for optically thick HCO$^{+}$ and HCN lines, and 0.39 and 0.45 for theiroptically thin isotopologues H$^{13}$CO$^{+}$ and HN$^{13}$C, respectively.This study reveals the physical and chemical properties of 30 high-mass IR-darkclumps and the interesting targets among them based on their emission linemorphology and kinematics.

MALT90 molecular content on high-mass IR-dark clumps