In the collision mode the detection limit of the studied elements decreases by order of two when helium flow rate increases. At the rise of the helium flow rate more than 2.5 ml/min, the changes of the detection limit are marginal (by order of one). In spite of the fact that maximum reduction of the detection limit of the studied elements is obtained at the helium flow rate of 3.2 ml/min, the intensity of the analytical signal is the lowest.