Patent ID: 11913917
Assignee: SHIMADZU CORPORATION
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 9:
10. A sample injection apparatus that injects a sample into a mobile phase that flows through an analysis flow path that extends from a high-pressure pump to a column in a chromatograph, the analysis flow path including an upstream analysis flow path comprising the high-pressure pump and a downstream analysis flow path comprising the column, the sample injection apparatus comprising:
a retention flow path that includes a needle at a downstream end and holds the sample suctioned from a sample container through the needle;
an injection flow path that includes an injection port at an upstream end and serves to inject into the analysis flow path, the sample injected from the needle into the injection port;
a low-pressure flow path having an upstream end connected to a measuring pump and a cleaning pump; and
a state switch valve that switches between a first state and a second state, the first state being a state in which the upstream analysis flow path and the downstream analysis flow path are connected to each other and a downstream end of the low-pressure flow path and an upstream end of the retention flow path are connected to each other, the second state being a state in which the upstream analysis flow path and the upstream end of the retention flow path are connected to each other and a downstream end of the injection flow path and the downstream analysis flow path are connected to each other;
wherein:
the retention flow path includes an upstream retention flow path on a side of the state switch valve and a downstream retention flow path on a side of the needle,
the low-pressure flow path includes an upstream low-pressure flow path on a side of the measuring pump and the cleaning pump and a downstream low-pressure flow path on a side of the state switch valve,
the sample injection apparatus further comprises:
a switch apparatus that includes a plurality of switch units, each of the switch units being made up of a combination of the upstream retention flow path, the injection flow path, the state switch valve, and the downstream low-pressure flow path,
a first multi-way switch valve that is provided in a midway along the retention flow path and makes switching of one of the upstream retention flow paths connected to the downstream retention flow path on a side of the downstream end of the retention flow path, and
a second multi-way switch valve that is provided in a midway along the low-pressure flow path and makes switching of one of the downstream low-pressure flow paths connected to the upstream low-pressure flow path on a side of an upstream end of the low-pressure flow path.