Automatic analyzer including HPLC and control method for the same
An automatic analyzer includes a liquid feed unit including a liquid feed unit and a liquid feed flow passage and feeding a mobile phase, a sample introduction unit introducing a sample to the mobile phase, a separation column separating the sample into plural components, a detector detecting the component, and a control unit. A pressure sensor detecting pressure of the liquid feed flow passage is provided, and the control unit calculates a pressure rise rate of the time immediately after starting liquid feeding of the mobile phase based on the pressure detected by the pressure sensor and a compression pressure variation amount and a pressure average after continuing liquid feeding of the mobile phase for a certain time, and determines completion of equilibration of the separation column.
1 . A control method of an automatic analyzer for HPLC, wherein the automatic analyzer includes:
a liquid feed unit including a liquid feed device and a liquid feed flow passage connected to the liquid feed device and feeding a mobile phase;
a sample introduction unit introducing a sample to the mobile phase fed from the liquid feed unit;
a separation column, the sample being introduced to the separation column from the sample introduction unit, the separation column separating the sample into a plurality of components;
a detector detecting the component separated by the separation column; and
a control unit controlling the liquid feed unit, the sample introduction unit, and the detector,
the liquid feed unit including a purge valve connected to the liquid feed flow passage and a waste liquid flow passage, the liquid feed unit and the sample introduction unit being connected to each other through a first analysis flow passage,
the purge valve being allowed to selectively connect the liquid feed flow passage to the first analysis flow passage or the waste liquid flow passage,
the sample introduction unit including a sample introduction valve introducing the sample to the mobile phase introduced from the first analysis flow passage,
the control method of an automatic analyzer for HPLC comprising steps of:
detecting pressure of the liquid feed flow passage;
calculating a pressure rise rate immediately after starting liquid feeding of the mobile phase by the liquid feed unit and a compression pressure variation amount and a pressure average after continuing liquid feeding of the mobile phase by the liquid feed unit by a certain time based on the pressure detected;
determining whether or not the pressure rise rate is within a specified rise rate value, the compression pressure variation amount is within a specified compression pressure variation amount value, and the pressure average is within a specified pressure range;
when the pressure rise rate is greater than the specified rise rate value, allowing a display unit to display an alarm for replacing the separation column, liquid feed flow passage, waste liquid flow passage, or first analysis flow passage;
in a case the pressure rise rate is within a specified rise rate, when the compression pressure variation amount is not within the specified compression pressure variation amount value, determining whether or not the pressure variation amount is within the specified pressure variation amount value by a predetermined number of times of determination, and when the compression pressure variation amount is not within the specified compression pressure variation amount value, allowing the display unit to display an alarm of purging and cleaning of the feed flow passage, waste liquid flow passage, or first analysis flow passage; and
in a case the pressure rise rate is within a specified rise rate and the pressure variation amount is within the specified pressure variation amount value, when the pressure average is within a specified pressure range, determining completion of equilibration of the separation column, when the pressure average is higher than a specified pressure upper limit value, allowing the display unit to display an alarm of replacing a separation column or piping, and when the pressure average is lower than a specified pressure lower limit value, determining in where leakage has occurred.
2 . The control method of an automatic analyzer for HPLC according to claim 1 , further comprising steps of:
when the pressure average is lower than the specified pressure lower limit value, determining whether or not the compression pressure variation amount is a specified compression pressure variation amount or below, when the compression pressure variation amount is the specified compression pressure variation amount or below, allowing the display unit to display an alarm that leakage of feed liquid has occurred from a cylinder within the liquid feed unit;
when the compression pressure variation amount is not the specified compression pressure variation amount or below, executing pressure check of the purge valve, when result of the pressure check is not within the specified pressure variation amount value, allowing the display unit to display an alarm that leakage of feed liquid has occurred on the upstream side of the purge valve;
when result of the pressure check of the purge valve is within the specified pressure variation amount value, executing pressure check of the sample introduction valve, when result of the pressure check of the sample introduction valve is not within the specified pressure variation amount value, allowing the display unit to display an alarm that leakage of feed liquid has occurred between the sample introduction valve and the purge valve, and when result of the pressure check of the sample introduction valve is within the specified pressure variation amount value, allowing the display unit to display an alarm that leakage of feed liquid has occurred downstream of the sample introduction valve.
3 . The control method of an automatic analyzer for HPLC according to claim 1 , the separation column being a plurality of separation columns arranged to be parallel to each other, the automatic analyzer including:
a bypass flow passage arranged in parallel to a plurality of the separation columns;
a first column switching valve capable of selectively connecting any one of a plurality of the separation columns and the bypass flow passage and the sample introduction valve to each other and capable of setting a state of not being selectively connected to any one of a plurality of the separation columns and the bypass flow passage; and
a second column switching valve capable of selectively connecting any one of a plurality of the separation columns and the bypass flow passage and the detector and capable of setting a state of not being connected selectively to any one of a plurality of the separation columns and the detector,
the control method of an automatic analyzer including HPLC comprising steps of:
when the pressure average is lower than the specified pressure lower limit value, determining whether or not the compression pressure variation amount is a specified compression pressure variation amount or below, when the compression pressure variation amount is the specified compression pressure variation amount or below, allowing the display unit to display an alarm that leakage of feed liquid has occurred from a cylinder within the liquid feed unit;
when the compression pressure variation amount is not the specified compression pressure variation amount or below, executing pressure check of the purge valve, when result of the pressure check is not within the specified pressure variation amount value, allowing the display unit to display an alarm that leakage of feed liquid has occurred on the upstream side of the purge valve;
when result of the pressure check is within the specified pressure variation amount value, executing pressure check of the sample introduction valve, when result of the pressure check of the sample introduction valve is not within the specified pressure variation amount value, allowing the display unit to display an alarm that leakage of feed liquid has occurred between the sample introduction valve and the purge valve, when result of the pressure check of the sample introduction valve is within the specified pressure variation amount value, executing pressure check of the first column switching valve, when result of the pressure check is not within the specified pressure variation amount value, allowing the display unit to display an alarm that leakage of feed liquid has occurred between the sample introduction valve and the first column switching valve;
when result of the pressure check of the first column switching valve is within the specified pressure variation amount value, executing pressure check of the second column switching valve, when result of the pressure check of the second column switching valve is not within the specified pressure variation amount value, allowing the display unit to display an alarm that leakage of feed liquid has occurred between the first column switching valve and the second column switching valve, and when result of the pressure check of the second column switching valve is within the specified pressure variation amount value, allowing the display unit to display an alarm that leakage has occurred on the downstream side of the second column switching valve.