JPH0687055B2 - Hydride generator - Google Patents

Description

The present invention relates to an atomic absorption spectrophotometer and a hydride generator applied to a high frequency induction plasma emission spectroscopic analyzer.

(B) Conventional technology It is possible to obtain good results by hydrogenating and vaporizing elements such as arsenic, selenium and antimony and performing atomic absorption analysis or high frequency induction plasma emission analysis. Conventionally, a device shown in FIG. 3 is known as a device for generating this hydride.
The hydride generator 21 is roughly divided into a hydrogenation reaction section 22 and a gas-liquid separation section 26.

The hydrogenation reaction section 22 includes a reaction coil 23, and at one end 23a thereof, the liquid sample S, hydrochloric acid (HCl) A, and a reducing agent R are
Pumped in. While the reaction solution formed by mixing the liquid sample, hydrochloric acid, and the reducing agent flows through the reaction coil 23, the reduction and hydrogenation reaction of the test element are performed. In addition,
At the reaction coil end 22a, a carrier gas (an inert gas such as argon is used) cg ₂ is further mixed in order to increase the moving speed of the reaction liquid in the reaction coil 23.

The gas-liquid separating section 26 is composed of a U-shaped tube 27. One end of the U-shaped pipe 27 is used as an introduction part 28 and the other end is used as a discharge part 32. The introduction portion 28 has the other end 23 of the reaction coil 23.
b is connected, and the reaction solution together with the carrier gas cg ₁
It is introduced into the introduction unit 28. In this introduction part 28, the hydrogenated and vaporized test element (hydride) and the reaction residual liquid are separated. The separated hydride is carried to a carrier gas and, in the case of atomic absorption analysis, is guided to a heating absorption cell 36. On the other hand, the reaction residual liquid D collects at the bottom of the U-shaped pipe 27, and the amount exceeding the predetermined level is discharged from the discharge port 32a.

(C) Problems to be Solved by the Invention In the above-described conventional hydride generator 21, since the hydride and the carrier gas are not completely mixed, the S / N ratio of the atomic absorption signal is reduced.
There was a problem that the ratio decreased and the measured value was not stable.

Further, the liquid droplets (mist) of the reaction residual liquid D are heated by the heat absorption cell 36.
However, there is a problem in that this is accumulated on the inner surface of the heat absorption cell 36 and causes noise. Not only that, the quartz glass forming the heat absorption cell 36 is heated in a water atmosphere due to the intrusion of this mist, and there is a risk that the heat absorption cell 36 will be devitrified and damaged. .

The present invention has been made in view of the above, and an object thereof is to provide a hydride generator capable of enhancing the mixing of a hydride and a carrier gas and preventing the reaction residual liquid mist from entering a heating absorption cell or the like.

(D) Means for Solving the Problems In order to solve the above problems, the hydride generation apparatus of the present invention has a hydrogenation reaction part for hydrogenating a test element in a sample, and the hydrogenation reaction part at its introduction part. A reaction liquid and a carrier gas are introduced from the above part, the test element hydride and the reaction residual liquid are separated, and the separated reaction liquid residue is discharged from the discharge part. In this case, the introduction part is divided into upper and lower parts by providing a small diameter part, and the carrier gas is introduced into the introduction part above from the tangential direction of the cross section of the introduction part, and the hydrogenation reaction part is present below the introduction part. The reaction liquid is further introduced from the tangential direction of the cross section of the introduction portion.

(E) Action In the hydride generator of the present invention, since the carrier gas and the reaction liquid are introduced into the introduction part from the tangential direction of the cross section, a vortex flow of the hydride in the carrier gas and the reaction liquid is formed in the introduction part. , The mixing of carrier gas and hydride is promoted.

On the other hand, since the introduction part is divided through the small diameter part and the reaction liquid is introduced to the lower side thereof, the mist of the residual reaction liquid is blocked by the small diameter part and does not easily go to the upper side, and is connected to the upper end of the introduction part. It is possible to prevent the mist from entering the heat absorption cell or the like.

(F) Embodiment One embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

FIG. 1 is an explanatory view showing a partially broken view of the hydride generator of the embodiment. The hydrogenation reaction section 2 has a reaction coil 3 similar to the conventional one. At one end 3a of the reaction coil 3,
The tube 4 is connected. This pipe 4 is branched into four parts 4a, 4b, 4c and 4d. Liquid samples S, hydrochloric acid A and sodium borohydride solution R are respectively supplied to the branches 4a, 4b and 4c by an ironing pump or the like. It has been sent. Further, the carrier gas cg ₂ is introduced from the branch 4d.

On the other hand, the gas-liquid separating section 6 is composed of a J-shaped tube 7 and a residual liquid chamber 13. One end of the J-shaped tube 7 serves as an introduction portion 8, and its upper end 9 is connected to a heating absorption cell or the like (not shown). Further, a small diameter portion 10 is formed in the introduction portion 8, and the introduction portion 8 is divided into an upper side 8a and a lower side 8b.

The carrier gas introduction pipe 11 and the reaction coil end 3b are introduced into the introduction part upper side 8a and the introduction part lower side 8b, respectively. As shown in FIG. 2A, the carrier gas introducing pipe 11 and the reaction coil end portion 3b are introduced from the tangential direction of the cross section of the introducing portion 8, and are arranged diagonally and opposite to each other.

The other end of the J-shaped pipe 7 serves as a discharge part 12 and opens upward at an appropriate level. The discharge part 12 is open in the residual liquid chamber 13, and the reaction residual liquid D overflowing from the discharge part 12 drops into the residual liquid chamber 13 and is discharged to the outside from the outlet 14. In addition, 15 is
This is an air vent hole of the residual liquid chamber 13.

Next, the operation of the example hydride generator 1 will be described.

Sample S, hydrochloric acid A, which respectively flowed in from the branches 4a, 4b, 4c,
The sodium borohydride solution R mixes in the tube 4 to form a reaction solution. This reaction solution is sent to the reaction coil 3 and the hydrogenation reaction of the test element in the sample proceeds. The carrier gas cg ₂ is blown in to increase the moving speed of the reaction liquid in the reaction coil 3.

The reaction liquid that has passed through the inside of the reaction coil 3 is introduced from the end portion 3b to the lower side 8b of the introduction portion. On the other hand, the carrier gas cg ₁ is introduced into the introduction part upper side 8a by the introduction pipe 11.

On the lower side 8b of the introduction part, vaporized hydride and carrier gas
cg ₂ is separated from the reaction liquid, and the remaining reaction liquid is accumulated in the bottom portion 7a of the J-shaped tube as the reaction residual liquid D. At this time, the hydride and the carrier gas cg ₂ form a vortex in the clockwise direction as shown by the chain double-dashed line in FIG. On the other hand, as shown in FIG. 2 (a), the carrier gas cg
A clockwise swirl of ₁ is formed. The mixing of the carrier gas and the hydride is promoted by these two vortexes. The mixed gas of the carrier gas and the hydride is introduced from the upper side 9 to a heating absorption cell (not shown) or the like.

On the lower side 8b of the introduction part, a mist of the reaction residual liquid is naturally generated, but this mist is blocked by the small diameter part 10
Since it is hard to reach the 8a, it is possible to prevent the mist from entering the heat absorption cell or the like.

When the reaction residual liquid D accumulated at the bottom of the J-shaped tube 7 exceeds the level h, it overflows from the discharge part 12 into the residual liquid chamber 13 and is further discharged from the outlet 14. The second (b) shows a modified example of the arrangement of the carrier gas introduction pipe 11 and the reaction coil end portion 3b. In this example, the carrier gas introduction pipe 11 and the reaction coil end portion 3b are introduced in the same direction and symmetrically with respect to the center plane C, and a counterclockwise vortex flow is introduced in the introduction portion upper side 8a. Clockwise vortices are formed on the lower side 8b of the introduction portion.

As shown in FIG. 2 (c), a carrier gas introducing pipe
It is also possible to arrange the 11 and the reaction coil end portion 3b so as to be in a straight line with the central axis of the J-shaped tube 7 in between when viewed from above. In this case, since eddy currents are hardly generated, promotion of mixing of the carrier gas and hydride cannot be expected so much, but intrusion of mist can be sufficiently prevented.

(G) Effect of the Invention As described above, the hydride generator of the present invention is
The introduction part is provided with a small diameter part and is divided into upper and lower parts, and the carrier gas is introduced into the introduction part upper side from the introduction part cross-section tangential direction, and the reaction liquid from the hydrogenation reaction part is introduced into the introduction part lower side. Since it is characterized in that it is introduced from the tangential direction of the cross section, it has the advantages that the mixing efficiency of the carrier gas and hydride can be increased and that the mist of the reaction residual liquid can be prevented from entering the heating absorption cell etc. is doing.

[Brief description of drawings]

FIG. 1 is a view showing a part of a hydride generator according to an embodiment of the present invention in a cutaway manner, and FIG. 2 (a) is taken along line II-II in FIG. 1 of the hydride generator. Sectional views, FIGS. 2 (b) and 2 (c) are cross-sectional views each illustrating a modification of the hydride generator, and FIG. 3 is a diagram illustrating a conventional hydride generator. . 2: Hydrogenation reaction part, 3b: Reaction coil end part, 6: Gas-liquid separation part, 8: Introduction part, 10: Small diameter part, 11: Carrier gas introduction pipe, 12: Discharge part, D: Reaction residual liquid.

Claims (1)

[Claims] 1. A hydrogenation reaction part for hydrogenating a test element in a sample, and a reaction liquid and a carrier gas from this hydrogenation reaction part are introduced into the introduction part to react with a test element hydride. In a hydride generation device comprising a gas-liquid separation unit in which a residual liquid is separated and the separated reaction residual liquid is discharged from the discharge unit, the introduction unit is divided into upper and lower parts by providing a small diameter part. The carrier gas is introduced from the introduction section cross-section tangential direction to the introduction section upper side, and the reaction liquid from the hydrogenation reaction section is introduced from the introduction section cross-section tangential direction to the introduction section lower side. Hydride generator.