Method for measuring change in physical quantity of adhered substance by qcm sensor

A silica-containing chemical solution for oil recovery which satisfies a relationship of ΔFA/ΔFB=0.8 to 400 and ΔDA/ΔDB=0.8 to 100 when a detection unit including a sensor in which a silicon dioxide-containing layer corresponding to bedrock is formed on a sensor part having a diameter of 15 mm in which a gold electrode is wired on a crystal resonator, and an oil layer corresponding to a petroleum layer is adhered onto the silicon dioxide-containing layer at 0.5 to 10 μg/cm2 is brought into contact with a fluid A containing, as components, salt water containing salts including sodium chloride at a concentration of 0.1 to 30% by mass and a silica-containing chemical solution for oil recovery or a fluid B containing the salt water but not containing the silica-containing chemical solution for oil recovery at a fluid flow rate of 0.01 to 5 mL/min at 25° C. and the sensor is resonated in a frequency range of 1 MHz to 100 MHz,

• wherein a value of ΔFA indicates a maximum value of a frequency change value ΔF indicating a change in a weight of the oil layer, which is detected by the sensor upon contact with the fluid A,
• a value of ΔDA indicates a local maximum value of an energy dissipation value ΔD indicating a change in an elastic modulus of the oil layer, which is detected by the sensor upon contact with the fluid A,
• a value of ΔFB indicates a maximum value of a frequency change value ΔF indicating a change in a weight of the oil layer, which is detected by the sensor upon contact with the fluid B, and
• a value of ΔDB indicates a local maximum value of an energy dissipation value ΔD indicating a change in an elastic modulus of the oil layer, which is detected by the sensor upon contact with the fluid B, and
• wherein the silica-containing chemical solution for oil recovery contains 0.0001 to 50% by mass of a silica and 0.001 to 40% by mass of a surfactant with respect to a mass of the silica.

A silica-containing chemical solution for oil recovery which satisfies a relationship of TC>TA when a detection unit including a sensor in which a silicon dioxide-containing layer corresponding to bedrock is formed on a sensor part having a diameter of 15 mm in which a gold electrode is wired on a crystal resonator, and an oil layer corresponding to a petroleum layer is adhered onto the silicon dioxide-containing layer at 0.5to 10 μg/cm2 is brought into contact with a fluid A containing, as components, salt water containing salts including sodium chloride at a concentration of 0.1 to 30% by mass and a silica-containing chemical solution for oil recovery or a fluid C containing the salt water and a silica-free chemical solution for oil recovery at a fluid flow rate of 0.01 to 5 ml/min at 25° C., and the sensor is resonated in a frequency range of 1 MHz to 100 MHz,

• wherein
• a value of TA is a time from when a change in an energy dissipation value ΔDA indicating a change in an elastic modulus of the oil layer starts until the energy dissipation value ΔDA reaches a maximum, which is detected by the sensor upon contact with the fluid A, and
• a value of TC is a time from when a change in an energy dissipation value ΔDC indicating a change in an elastic modulus of the oil layer (=ΔDB value) starts until the energy dissipation value ΔDC becomes a maximum, which is detected by the sensor upon contact with the fluid C.