JPS60207038A - Flow cell for liquid chromatography - Google Patents

Abstract

PURPOSE:To reduce the background of a detector, by making the fused surfaces of cell members black, thereby avoiding the transmission of the excited light on the fused surfaces, scattered light of stray light and light, which is reflected and turned by the cell members, into the side of a fluorescent spectroscope. CONSTITUTION:Four transparent quartz cell members 20-1-20-4 having a trapezoidal cross section are fused at fusing surfaces 21-1-21-4 in the diagonal directions. Thus a hollow prism shaped flow cell having a an internal diameter of about 1mm. is formed. The fused surfaces 21-1-21-4 have a black color. A sample flows in the flow cell at a moving phase. Exciting light 3 is inputted and fluorescent light 5 is extracted. At this time, even though the exciting light 3 or stray light is reflected by the fused surface 21-1 and scattered light 22 is obtained, the light is shielded by the black fused surface 21-2 and is not transmitted in the direction of the fluorescent light 5, i.e., the direction, where a fluorescent spectroscope is present. Even though the excited light or the stray light is reflected between the emitting surface and incident surface of the cell member 20-1 and transmitted through the inside of the cell member 20-1, the light is likewise shielded by the black fused surface 21-2 and is not transmitted in the direction of the fluorescent light 5.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a flow cell used in a liquid chromatograph using a spectrofluorometer as a detector.

(Prior Art) FIG. 1 shows a fluorescence measurement system used as a detector for a liquid chromatograph.

(2) is a flow cell, through which the sample components separated by the column are sent along with the mobile phase. Excitation light 3 emitted from a light source 2 such as a xenon lamp or a mercury lamp is separated by an excitation light spectrometer 4 and irradiated onto the sample in the flow cell 1.The excitation light irradiation excites the emitted fluorescence 5. The light is extracted in a direction perpendicular to the light 3, separated by a fluorescence spectrometer 6, and then detected by a photodetector 7 such as a photomultiplier tube.

As shown in FIG. 2, a conventional flow cell 1 is formed into a hollow prismatic shape by welding together four transparent quartz cell members 9, through which a mobile phase passes as shown by the arrow. The four fused surfaces 10 are also transparent.

By the way, when excitation light 3 enters such a transparent flow cell, the excitation light 3 or stray light is scattered by the fusion surface 10-1 and transmitted through the fusion surface 10-2 as shown in FIG. The excitation light 3 becomes scattered light 11 in a direction perpendicular to 3, or travels through the interior of the cell member 9 into which the excitation light 3 is incident, and reaches the fusion surface 10-2.
, and enters the fluorescence spectrometer 6 as scattered light 12 in a direction orthogonal to the excitation light 3 from the cell member 9 on the side surface. This scattered light 11, 12 becomes strong background light, increases base noise, and poses a problem of worsening the detection limit.

(Objective) An object of the present invention is to provide a blow cell for liquid chromatography that prevents excitation light and stray light from being scattered in the direction of a fluorescence spectrometer.

(Structure) The flow cell of the present invention is formed into a hollow prismatic shape by welding four cell members, and the fused surface is blackened or a black member is interposed on the fused surface. By doing so, the scattered light is prevented from passing through the fused surface, thereby preventing the scattered light from entering the fluorescence spectrometer.

(Example) FIG. 4 represents one embodiment of the present invention.

Four transparent quartz cell members 20-1 to 20-2 with trapezoidal cross sections
0-4 are welded to diagonal welding surfaces 21-1 to 21-4 to form a hollow prismatic flow cell with an inner diameter of about 1 mm. Each of the fusion surfaces 21-1 to 21-4 is black.

In order to blacken the fused surfaces 21-1 to 21-4, a thin black quartz plate or a thin black glass plate may be interposed on the fused surfaces and fused. Further, after the surfaces of the cell members 20-1 to 20-4 to be fused are blackened by black quartz technology, the fused surfaces 2o-1 to 20-4 are fused.
1-1 to 21-4 may be blackened.

When a mobile phase is flowed through the flow cell of this embodiment and excitation light 3 is made incident as shown in FIG. 5 to extract fluorescence 5, the excitation light 3 or stray light is reflected by the fusion surface 21-1 and the scattered light 22
Even if , the light is blocked by the black fusion surface 21-2,
It does not transmit in the direction of the fluorescence 5, that is, in the direction of the fluorescence spectrometer.

Furthermore, even if the excitation light or stray light is reflected between the exit surface and the entrance surface of the cell member 20-1 and propagates inside the cell member 20-1, the light is still blocked by the black fusion surface 21-2 and the fluorescence is A T-note that is transparent in the direction of 5.

FIG. 6 shows another embodiment of the present invention, in which four prismatic quartz cell members 30-1 to 30-4 are fused together to form a hollow prismatic flow cell. In this embodiment, the fusion surface 3
1-1 to 31-4 are surfaces parallel to the side surfaces of the flow cell, which are colored black using the same technique as in FIG. 4.

In this embodiment as well, the blackened fused surface prevents the excitation light and scattered light of stray light from exiting to the fluorescence spectrometer side, as in the case of FIG.

FIG. 7 shows an example of a holding method when the flow cell of the present invention is used in a liquid chromatograph. The upper and lower end surfaces of the flow cell 40 are sandwiched between pipe members 42 and 42 via backings 41 and 41, and each member is held by a holding member 44 using screws 43 and 43. The mobile phase flows through the formed channel 45, the excitation light 3 is incident through the opening 46 of the holding member 44 in a direction perpendicular to the plane of the paper, and the fluorescence 5 from the sample excited by the excitation light is transmitted to the holding member 44. The excitation light 3 is extracted in a direction perpendicular to the excitation light 3 through an opening 47.

(Effects) In the flow cell of the present invention, the fused surface of the cell member is blackened, so that excitation light and scattered light from stray light on the cell fused surface, as well as wraparound light reflected within the cell member, can be detected by fluorescence spectroscopy. This has the effect of reducing the background of the detector and improving detection accuracy.

[Brief explanation of drawings]

Figure 1 is a perspective view of a liquid chromatograph fluorescence measurement system, Figure 2 is a perspective view of a conventional flow cell, and Figure 3 is a perspective view of a conventional flow cell.
The figure is a plan view showing the state of scattering of excitation light and stray light in the same flow cell, FIG. 4 is a perspective view showing one embodiment of the present invention, and FIG. A plan view showing,
FIG. 6 is a perspective view showing another embodiment, and FIG. 7 is a sectional view showing an example of use of the flow cell of the present invention. 20-1~20-4.30-4~30-4...
cell parts. 21-1~21-4.31-1~31-4...
Fusion surface, 40...flow cell. Agent Patent Attorney Shigeo Noguchi

Claims (1)

[Claims] (1) In the flow cell for graphing liquid chroma 1,
A flow cell characterized in that four quartz cell members are fused together in a prismatic shape, and the fused surfaces are blackened or a black member is interposed on the fused surfaces.