Flow cell

Abstract

The flow cell is composed of a cell block and a cell holder. The cell block is light transmittable and is provided with a plurality of cells communicated with each other and mutually different in optical path length and an inlet and an outlet communicated with the cell. The plurality of cells include a short optical path length cell having an optical path length of 100 m or less. The short optical path length cell is constituted by a groove formed on an inner joining surface of a plurality of laminated light transmitting substrates. The optical path length of the short optical path length cell is defined by a depth of the groove. The cell holder is configured to accommodate the cell block therein, and is provided with an incident window for allowing light to enter the cell block and an emission window for emitting the light transmitted through the cell block.

Claims

1. A flow cell comprising: a light transmitting cell block, wherein the cell block is provided with a plurality of cells communicated with each other and mutually different in optical path length and an inlet and an outlet communicated with the cells and formed on a surface of the cell block, the cell block being formed from a plurality of light transmitting substrates laminated with each other, the plurality of cells being constituted by grooves having different depths from each other and are formed on a surface of a common transmitting substrate of the plurality of light transmitting substrates, the optical path length of each cell being defined by the depth of a respective one of the grooves, and one of the plurality of cells is a short optical path length cell having an optical path length of 100 m or less; and a cell holder configured to accommodate the cell block therein and provided with an incident window for allowing light to enter the cell block and an emission window for emitting the light transmitted through the cell block.

2. The flow cell as recited in claim 1, wherein the plurality of cells of the cell block include a long optical path length cell configured by a through-hole provided in an intermediate substrate sandwiched between the plurality of light transmitting substrates.

3. The flow cell as recited in claim 2, wherein the optical path length of the long optical path length cell is 1 mm or more.

4. The flow cell as recited in claim 1, wherein the cell holder includes: a fixed block provided with an incident window and fixed in position; and a movable block configured to hold the cell block and provided with the emission window, the movable block being fixed to the fixed block in a state in which the cell block is positioned with respect to the incident window so that a desired cell is arranged on an optical axis of the incident light from the incident window.

5. The flow cell as recited in claim 4, wherein an engagement structure for defining a relative position between the fixed block and the movable block for placing a desired cell on the optical axis of the incident light from the incident window on mutual abutting surfaces of the fixed block and the movable block.

6. The flow cell as recited in claim 4, wherein the movable block is provided with a flow path therein communicated with the inlet and the outlet of the cell block.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a cross-sectional view showing a cell block in a flow cell of one embodiment.

(2) FIG. 2 is a cross-sectional view schematically showing the structure of the flow cell of the embodiment.

(3) FIG. 3 is a cross-sectional view showing a state in which the position of the cell block is changed in the aforementioned embodiment.

(4) FIG. 4 is a cross-sectional view showing a cell block in a flow cell of another embodiment.

EMBODIMENTS FOR CARRYING OUT THE INVENTION

(5) Hereinafter, one embodiment of a flow cell will be described below with reference to the drawings.

(6) First, a cell block 2 in the flow cell of this embodiment will be described with reference to FIG. 1.

(7) The cell block 2 used for the flow cell of this embodiment is constituted by joining quartz substrates 4 and 6 which are two light transmitting substrates. In the cell block 2, a cell 8 and a cell 10 continuously communicated with the cell 8 are provided. On a surface of the substrate 4 opposite to the inner joining surface thereof, an inlet 12 communicated with the end of the cell 8 and an outlet 14 communicated with the end of the cell 10 are provided. A sample flows into the cell block 2 from the inlet 12, flows through the cell 8 and the cell 10 in order, and then flows out from the outlet 14 to the outside of the cell block 2.

(8) In the following description, of the main surfaces of the cell block 2, the surface on the side where the inlet 12 and the outlet 14 are provided is denoted as a front surface, and the surface on the opposite side thereof is denotes as a rear surface.

(9) The cell block 2 is used so that light travels in a direction perpendicular to the front surface and the rear surface of the substrates 4 and 6 (in the vertical direction in the drawing). The optical path length a1 of the cell 8 is about 100 m, and the optical path length a2 of the cell 10 is about 10 m. That is, the cell block 2 has two short optical path length cells each having an optical path length of 100 m or less.

(10) The cell block 2 can be easily produced by using an etching technique. First, a groove having a depth a1 and a groove having a depth a2 are formed on one surface of a quartz substrate 4 by using an etching technique, and then through-holes communicated with the ends of the grooves are formed by drilling or laser processing. Thereafter, a substrate 6 is stacked on one surface side of the substrate 4, and the two substrates 4 and 6 are joined by thermal fusion bonding or the like. As a result, a cell block 2 having two short optical path length cells 8 and 10 different in optical path length therein is completed.

(11) Next, an embodiment of a flow cell using the cell block 2 will be described with reference to FIG. 2 and FIG. 3.

(12) The cell block 2 is accommodated in a cell holder composed of a fixed block 16 and a movable block 18. The movable block 18 is fixed to the fixed block 16 by fastening bolts (not shown). By loosening the bolts, the movable block 18 can be moved relative to the fixed block 16 in the direction parallel to the abutting surface abutting with the fixed block 16 (in the vertical direction in the drawing). The cell block 2 is held by the movable block 18.

(13) The movable block 18 is composed of a first block 24 arranged on the fixed block 16 side and abutting against the fixed block 16 and a second block 26 arranged on the opposite side of the fixed block 16 across the first block 16. A recess 25 for fitting the cell block 2 is provided on the surface of the second block 26 side (the right side in the drawing) of the first block 24, and an opening 40 is provided on the bottom surface of the recess 25.

(14) The cell block 2 is fitted into the recess 25 so that its front surface and rear surface are parallel to the movement direction (vertical direction in the drawing) of the movable block 18 and the surface on which the inlet 12 and outlet 14 are provided is arranged on the second block 26 side. The opening 40 is provided in such a size that the range where the cells 8 and 10 are provided on the back surface of the cell block 2 is exposed to the fixed block 16 side.

(15) The second block 26 is provided with flow paths 30 and 32 respectively communicated with the inlet 12 and the outlet 14 of the cell block 2. The second block 26 is fastened to the first block 24 by fastening the bolts 28 in a state in which O-rings 34 and 36 are sandwiched between the ends of the flow paths 30 and 32 on the cell block 2 side and the inlet 12 and the outlet 14. Although not shown, the flow paths 30 and 32 are communicated with piping connection ports for connecting pipes.

(16) In the fixed block 16, as shown by the broken line arrow in the drawing, an incident window 20 for allowing light to be incident in a direction (left and right direction in the drawing) perpendicular to the front and rear surfaces of the cell block 2 held by the movable block 18 is provided. In the second block 26 of the movable block 18, an emission window 22 for emitting the light incident from the incident window 20 and passed through the cell block 2 is provided.

(17) The mutual abutting surfaces of the fixed block 16 and the first block 24 have an engagement structure for positioning the cell block 2 with respect to the incident window 20. In this embodiment, a protrusion 42 is provided on the fixed block 16 side, and recesses 44a and 44b for fitting the protrusion 42 are provided on the first block 24 side.

(18) The recess 44a defines the position of the cell block 2 for placing the cell 10 on the optical axis of the incident light from the incident window 20. By positioning the movable block 18 so that the protrusion 42 is fitted in the recess 44a and fastening the fixed block 16 and the movable block 18 by tightening bolts (not shown), the cell block 2 is positioned so that the incident light passes through the cell 10 (the state of FIG. 2).

(19) Further, the recess 44a defines the position of the cell block 2 for placing the cell 8 on the optical axis of the incident light from the incident window 20. By positioning the movable block 18 so that the protrusion 42 is fitted in the recess 44b and fastening the fixed block 16 and the movable block 18 by tightening bolts (not shown), the cell block 2 is positioned so that the incident light passes through the cell 8 (the state of FIG. 3).

(20) In this manner, by changing the relative positional relationship between the fixed block 16 and the movable block 18, it becomes possible to change the optical path length of the cell through which the light incident from the incident window 20 passes. Thus, even without changing the flow cell itself, it is possible to change the optical path length according to the concentration of the sample.

(21) Note that the engagement structure for positioning the cell block 2 is not limited to the above, and for example, protrusions 42 may be provided on the first block 24 side, and recesses 44a and 44b may be provided on the fixed block 15 side.

(22) Next, another embodiment of a flow cell will be described. Since the structure of the cell holder for accommodating the cell block and changing the position of the cell block is basically the same as that of the above-described embodiment, only the structure of the cell block will be described in detail here.

(23) The cell block 2 used for the flow cell of this embodiment is constituted by stacking three light transmitting substrates 46, 48, and 50. The substrates 46, 48 and 50 are, for example, quartz substrates. In the cell block 2, three cells 52, 54, and 56 communicated with each other and having optical path length different from each other are provided. In the same manner as in the cell block 2 of the above-described embodiment, the cell block 2 is used by passing light in a direction (vertical direction in the drawing) perpendicular to the front and rear surfaces of the substrates 46, 48, and 50. The optical path length a3 of the cell 52 is about 1 mm, the optical path length a4 of the cell 54 is about 100 and the optical path length a5 of the cell 56 is about 10 m.

(24) On the surface of the cell block 2 on the substrate 46 side, an inlet 58 communicated with the end of the cell 52 and an outlet 60 communicated with the end of the cell 56 are provided. A sample flows into the cell block 2 from the inlet 58, flows through the cell 52, the cell 54, and the cell 56 in order, and then flows out from the outlet 60 to the outside of the cell block 2.

(25) This cell block 2 can be easily produced by using an etching technique in the same manner as in the cell block 2 of the above-described embodiment. In the cell block 2 of this embodiment, the cell 52 is formed by a through-hole provided in the intermediate substrate 48 sandwiched between the substrate 46 and the substrate 50. The cells 54 and 56 are formed by grooves provided on one surface of the substrate 46.

(26) In the flow cell using this cell block 2, by placing any one of the cells 52, 54, and 56 on the optical axis of the incident light from the incident window, the optical path length of light passing through the sample flowing cell can be changed. In particular, in the cell block 2, the cell 52 having a relatively long optical path length which is the same length as the thickness a3 of the substrate 48 is provided in addition to the short optical path length cells 54 and 56 having the optical path length of 100 m or less. Therefore, the selection range of the optical path length according to the concentration of the sample is wide, and the dynamic range of the detector can be increased.

DESCRIPTION OF REFERENCE SYMBOLS

(27) 2, 2 cell block 4, 6, 46, 48, 50 light transmitting substrate 8, 10, 52, 54, 56 cell 12, 58 inlet 14, 60 outlet 16 fixed block 18 movable block 20 incident window 22 emission window 24 first block 26 second block 30, 32 flow path 34, 36 O-ring 40 opening 42 protrusion 44a, 44b recess