Flotation is used for separating mineral particles. Flotation is accompanied by entrainment of hydro- philic particles which is an undesirable process. Flotation and entrainment depend on numerous pa- rameters, among them the presence and concentration of frother. This work was devoted to investi- gate the borderline between entrainment and flotation of quartz particles in the so-called monobubble Hallimond tube in the presence of varying concentrations of selected frothers. The following frothers were used: octyl alcohol, isoamyl alcohol, α-terpineol, tricosene-ethyleneglycol 1-hexadecanoic ether and corflot (a mixture of butyl ethers of di-, tri- and tetraethylene glycols). Entrainment of the quartz particles in pure water has also been conducted as a reference test. The work has confirmed that en- trainment depends on particle size. It also confirmed the role of the frother used. Two of the frothers: tricosene-ethylene glycol 1-hexadecanoic ether and octyl alcohol have exhibited both frothing and collecting properties.