JPS6338096B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is provided between a gas chromatograph and a subsequent analysis device such as a mass spectrometer, and is used to detect substances representing peaks that do not require analysis among the solvent and sample components flowing out from the gas chromatograph. This relates to a device that blocks the flow into a subsequent analysis device.

This type of device is generally called a solvent diverter, etc., and is used to prevent the inside of the subsequent analyzer from being contaminated with unnecessary components, but the conventional solvent diverter is as shown in Figure 1. A branch pipe D is provided in the middle of the pipe system T that connects the gas chromatograph G and another analyzer M, and this branch pipe D is connected to the exhaust pump P via the opening valve V to prevent unnecessary gas from passing through. The structure was such that the valve V was opened to remove it by suction. However, in this configuration, when the valve V is closed and the necessary components flow toward the analyzer M, the space inside the branch pipe D and the valve V becomes a dead space, and even after the peak of the sample component has passed, this dead space remains. Sample components that have diffused into the dead space and stayed or adhered to the wall may gradually flow out of the dead space, resulting in a peak with a trailing tail, or may be mixed into other components as they pass through. There was a problem that the accuracy of analysis was reduced. The present invention aims to solve the above-mentioned problems in conventional solvent diverters.

Figure 2 shows an embodiment of the device of the present invention, which is a device in which a gas chromatograph and a mass spectrometer are connected via a molecular separator. Connect S with T-shaped tube J, and connect T-shaped tube J.
An exhaust pump P is connected to the branch path J2 through an on-off valve V, and while components unnecessary for analysis are flowing out from the gas chromatograph G, the valve V is opened and the components are discharged from the branch path J2. In this configuration, the diameter of the communication port A to the branch passage J2 opened in the inner wall of the main passage J1 of the T-shaped pipe J is set as the branch passage J.
The branch path J2 is formed smaller than the inner diameter of J2.
A ball B is housed inside the branch passage J2, and the ball B is pressed against the communication port A by the spring pressure of a weak spring R inserted into the branch path J2, thereby closing the communication port A. Actually, as shown in FIG. 2b, the outflow side piping of the on-off valve V merges with the exhaust pipe of the molecular separator S and is connected to the exhaust pump P. In Fig. 2a, the spring R is required because the branch J2 is provided facing downward, but the ball's own weight is used as a means to bias the ball toward the opening between the branch and the main pipe. If this is utilized and the branch path J2 is provided facing upward, the ball B will close the communication port A with its own weight, so the spring R will be unnecessary.

When the on-off valve V is opened and the pressure inside the branch passage J2 is reduced, the ball B, which had been in contact with the communication port A with a slight pressure, is pushed due to the pressure difference between the main passage J1 and the branch passage J2. The gas flow, which was opened and directed from the gas chromatograph G to the molecular separator S, changes direction and is discharged from the branch path J2.

The present invention is constructed as described above, and when unnecessary gas is not discharged to the branch passage J2, the communication port A provided on the inner wall of the main passage J1 to the branch passage J2 is connected to the ball B. As a result, the branch pipe D and valve V do not become a dead space as in the past, and as a result, solvents and unnecessary components may remain in the dead space or adhere to the walls within the dead space. It has the advantage that there is no risk of it later flowing into the main flow path and reducing analysis accuracy.

[Brief explanation of the drawing]

FIG. 1 is a schematic system diagram showing a conventional example, FIG. 2a is a sectional view of essential parts showing an embodiment of the apparatus of the present invention, and FIG. 2b is a schematic system diagram of the same. G is a gas chromatograph, C is a column, S is a molecular separator, M is an analyzer, J is a T-tube, J1
is a main flow path, J2 is a branch path, B is a ball, R is a spring, A is a communication port, V is an on-off valve, and P is an exhaust pump.

Claims (1)

[Claims] 1 Connect a branch line to the main line connecting the end of the gas chromatograph column and the subsequent device, connect this branch line to the exhaust pump via an on-off valve,
In a configuration in which unnecessary components in the gas flowing out from the glass chromatograph are discharged from the branch passage, the diameter of the communication port opened in the inner wall of the main pipe of the branch passage is set to be larger than the inner diameter of the branch passage itself. A gas chromatograph and subsequent analysis characterized in that the ball is formed small and housed in the branch channel, and the ball is brought into pressure contact with the communication port by means of urging the ball toward the communication hole to close the communication port. Sample introduction cutoff device between devices.