Defective point estimation method and liquid chromatograph

A defective point estimation method for estimating a defective point of a liquid chromatograph, the method comprising:

• discharging a solvent into a flow path by a double plunger pump including a first plunger pump, a second plunger pump disposed downstream of the first plunger pump, and a plurality of consumables relating to the discharge of the solvent;
• introducing a sample into the flow path;
• detecting a pressure of the solvent discharged by the double plunger pump;
• separating components of the sample by a separation column;
• detecting the components separated by the separation column;
• estimating a defective consumable among the plurality of consumables based on a first pressure detected in a first section in which the first plunger pump discharges the solvent into the flow path and a second pressure detected in a second section in which the second plunger pump discharges the solvent into the flow path;
• discharging a solvent different from the solvent into the flow path by one or a plurality of double plunger pumps different from the double plunger pump;
• acquiring a retention time of an internal standard substance supplied to the flow path when the component of the sample is detected, and comparing the retention time with a predetermined value to determine whether the retention time is earlier or later than the predetermined value;
• and estimating a defective double plunger pump among the plurality of double plunger pumps based on a determination result of the retention time, a type of the separation column, and a type of the solvent.

A defective point estimation method for estimating a defective point of a liquid chromatograph, the method comprising:

• discharging a solvent into a flow path by a double plunger pump including a first plunger pump, a second plunger pump disposed downstream of the first plunger pump, and a plurality of consumables relating to the discharge of the solvent;
• introducing a sample into the flow path;
• detecting a pressure of the solvent discharged by the double plunger pump;
• separating components of the sample by a separation column;
• detecting the components separated by the separation column;
• and
• estimating a defective consumable among the plurality of consumables based on a first pressure detected in a first section in which the first plunger pump discharges the solvent into the flow path and a second pressure detected in a second section in which the second plunger pump discharges the solvent into the flow path, wherein
• the plurality of consumables include a first seal of the first plunger pump, a first check valve disposed upstream of the first plunger pump, a second check valve disposed downstream of the first plunger pump, and a second seal of the second plunger pump, and
• estimating the defective consumable includes:
• estimating that the second check valve is defective when the first pressure is not abnormal and the second pressure is abnormal,
• estimating that the first seal or the first check valve is defective when the first pressure is abnormal and the second pressure is not abnormal, and
• estimating that the second seal is defective when the first pressure and the second pressure are abnormal.

A liquid chromatograph, comprising:

• a double plunger pump including a first plunger pump, a second plunger pump disposed downstream of the first plunger pump, and a plurality of consumables relating to discharge of a solvent;
• a pressure sensor configured to detect a pressure of the solvent discharged by the double plunger pump;
• a dispensing unit configured to introduce a sample into a flow path;
• a separation column connected downstream of the dispensing unit and configured to separate the sample into components;
• a detection unit configured to detect the components separated by the separation column;
• a control unit configured to estimate a defective consumable among the plurality of consumables based on a first pressure detected by the pressure sensor in a first section in which the first plunger pump discharges the solvent into the flow path and a second pressure detected by the pressure sensor in a second section in which the second plunger pump discharges the solvent into the flow path;
• and
• one or a plurality of double plunger pumps different from the double plunger pump and configured to discharge a solvent different from the solvent into the flow path, wherein
• the control unit acquires a retention time of an internal standard substance supplied to the flow path when the component of the sample is detected, compares the retention time with a predetermined value to determine whether the retention time is earlier or later than the predetermined value, and estimates a defective double plunger pump among the plurality of double plunger pumps based on a determination result of the retention time, a type of the separation column, and a type of the solvent.

A liquid chromatograph, comprising:

• a double plunger pump including a first plunger pump, a second plunger pump disposed downstream of the first plunger pump, and a plurality of consumables relating to discharge of a solvent;
• a pressure sensor configured to detect a pressure of the solvent discharged by the double plunger pump;
• a dispensing unit configured to introduce a sample into a flow path;
• a separation column connected downstream of the dispensing unit and configured to separate the sample into components;
• a detection unit configured to detect the components separated by the separation column;
• and
• a control unit configured to estimate a defective consumable among the plurality of consumables based on a first pressure detected by the pressure sensor in a first section in which the first plunger pump discharges the solvent into the flow path and a second pressure detected by the pressure sensor in a second section in which the second plunger pump discharges the solvent into the flow path, wherein
• the plurality of consumables include a first seal of the first plunger pump, a first check valve disposed upstream of the first plunger pump, a second check valve disposed downstream of the first plunger pump, and a second seal of the second plunger pump, and
• the control unit
• estimates that the second check valve is defective when the first pressure is not abnormal and the second pressure is abnormal,
• estimates that the first seal or the first check valve is defective when the first pressure is abnormal and the second pressure is not abnormal, and
• estimates that the second seal is defective when the first pressure and the second pressure are abnormal.

A defective point estimation method for estimating a defective point of a liquid chromatograph, the method comprising:

• mixing a plurality of types of solvents and discharging the mixed solvents into a flow path by a plurality of plunger pumps;
• introducing a sample into the flow path;
• separating components of the sample by a separation column;
• detecting the components separated by the separation column;
• acquiring a retention time of an internal standard substance supplied to the flow path when the component of the sample is detected, and comparing the retention time with a predetermined value to determine whether the retention time is earlier or later than the predetermined value;
• and
• estimating a defective plunger pump among the plurality of plunger pumps based on a determination result of the retention time.

A liquid chromatograph, comprising:

• a plurality of plunger pumps configured to mix a plurality of types of solvents and discharge the mixed solvents into a flow path;
• a dispensing unit configured to introduce a sample into the flow path;
• a separation column connected downstream of the dispensing unit and configured to separate the sample into components;
• a detection unit configured to detect the components separated by the separation column;
• and
• a control unit configured to acquire a retention time of an internal standard substance supplied to the flow path when the component of the sample is detected, compare the retention time with a predetermined value to determine whether the retention time is earlier or later than the predetermined value, and estimate a defective plunger pump among the plurality of plunger pumps based on a determination result of the retention time.