JPH0223829B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to an analyzer for reducing vaporizable elements, and particularly relates to a hydrogen analyzer suitable for analyzing gaseous hydride elements and simple elements produced by reduction reactions. The present invention relates to an analysis device equipped with a chemical generator.

[Background of the invention]

It is known that elements such as arsenic, selenium, antimony, and bismuth easily become hydrogen compounds and become gaseous vapors in the presence of nascent hydrogen produced by chemical reactions. It is also known that mercury vaporizes as free mercury in the presence of a reducing agent. Highly sensitive analysis has already been carried out by applying the above-mentioned properties of these elements. One method is to put a certain amount of a sample containing the target element into a sealable glass container, add an acid and a reducing agent into the container, vaporize the target element as a hydride, and after a certain period of time, The hydride vapor is introduced into the atomization section of the atomic absorption spectrometer to atomize the target element and perform atomic absorption measurement.

In this method, the acid used is hydrochloric acid or sulfuric acid, and the reducing agent used is metallic zinc or sodium borohydride. This method is a so-called batch method, and it requires preparing as many containers as the number of samples, changing containers for each sample, or having the measurer perform the above operations, making it difficult to perform quick measurements. It was difficult to automate.

For these reasons, recently, solutions of acids and reducing agents are continuously flowed, and they are merged to generate nascent hydrogen, and a sample containing the target element is merged at the confluence point to generate hydrides. A method was considered in which the vapor was generated and introduced into the atomization section of the atomic absorption spectrometer using argon gas or the like. This method is a so-called flow method, and has improved the above-mentioned problems. However, looking at the amount of signal, in the case of the batch method, the amount of sample is large, and the signal obtained is the peak signal that indicates the saturation of the elements contained in the sample, whereas in the flow method, the signal obtained is the peak signal of the saturation of the elements contained in the sample. Because the elemental amounts are obtained as a continuous signal, the recorded signal height is much larger with the batch method, and the sensitivity of the flow method is lower.

[Purpose of the invention]

An object of the present invention is to provide an analyzer for reductive vaporizable elements that can achieve highly sensitive measurement using a flow method in which sample components undergo a reduction reaction within a flow path.

[Summary of the invention]

The present invention includes a mixing section in which an acid solution and a reducing agent solution are constantly supplied and hydrogen is generated, a sample measuring section for weighing a fixed amount of a sample, and a processing section for introducing the sample from the sample measuring section into the mixing section. A pressurized inert gas supply means is provided.

[Embodiments of the invention]

A preferred embodiment of the present invention has a plurality of pump functions for transporting the sample, the acid, and the reducing agent, and the sample flow path system has a part for weighing a certain amount of the sample, It has various flow path systems in which this fixed amount of sample is mixed with acid and reducing agent,
Inside the flow path system, there is a flow path for other types of gas that transports hydride and hydrogen gas generated when the sample, acid, and reducing agent are mixed to the atomization section, and one of the gas flow paths is A hydride generator for atomic absorption spectrometry that is connected in front of the part where a fixed amount of sample is weighed, and after a fixed amount of sample is weighed, the sample is pumped by the pressure of this gas and mixed with acid and reducing agent. can be provided. In a preferred embodiment, the part for weighing a fixed amount of the sample is composed of electrically movable valves, and has at least two or more timers for driving the valves, and the valve is switched after weighing the fixed amount of the sample. It has the function of setting the time for feeding the sample with gas, the time for reaction to occur and hydride to be generated, and the time for returning to the original state after the measurement is completed.

In the embodiment of the present invention, while taking advantage of the characteristics of the flow method, such as rapid measurement, ease of operation, and ease of automation, the disadvantage of low sensitivity is eliminated by weighing a fixed amount in the sample flow path. By rapidly sending the weighed sample to the reaction section under the pressure of carrier gas, a highly sensitive measurement result is obtained by obtaining the sum of the elements contained in the weighed sample as a peak signal.

FIG. 1 shows an embodiment of the present invention. In this embodiment, a sample measuring section 17 is provided, and a weighed sample is rapidly fed into a manifold 11 having a larger capacity than this measuring section 17 using a pressurized inert gas.

Reducing agent (sodium borohydride), acid (hydrochloric acid), potassium iodide, and sample are placed in each pump 7,
8, 9, and 10. Initially, the sample 6 is sent to the valve 19 through the valve 20 by the liquid sending pump 10, and flows into the sample waste liquid tank 23 via the metering coil 17 and the valve 21. At this time, potassium iodide 5 is sent by a pump 9, mixed in an argon gas mixer 24, and led to a manifold 11 via a valve 18 and a bypass 16.
Sodium borohydride 3 and hydrochloric acid 4 are constantly pumped to manifold 11 by pumps 7 and 8 . Therefore, hydrogen is always generated in this manifold 11.

After metering coil 17 is filled with sample 6, the flow paths of valves 18, 19, 20 and 21 are switched. As a result, the sample 6 is directly transferred to the sample waste liquid tank 2.
3, but at this point the sample 6 is removed.
On the other hand, the sample in the metering coil 17 is fed by potassium iodide, but since argon gas is connected to the potassium iodide flow path, the sample is actually fed by the pressure of the argon gas. It is quickly fed into the manifold 11.

Since a large amount of hydrogen is always generated in the manifold 11, arsenic in the sample sent to the manifold 11 immediately turns into hydrogen arsenide, and the reaction coil 2
2. The gas is sent to the atomization section 2 via the gas-liquid separator 13. 1 is an atomic absorption photometer.

The flow paths of each valve are shown in FIGS. 2 and 3.
FIG. 2 shows the flow path during the process of filling the metering coil 17 with the sample 6, and the flow path inside the valve is shown by a broken line. FIG. 3 shows the flow path during which the sample filled in the metering coil 17 is transported by argon gas. The role of these valves can be fulfilled by using, for example, a six-way valve, but since it is cheaper to use such a valve, it has been explained using a diagram. By rapidly introducing the sample into the hydrogen generating section (manifold 11) using gas pressure in this manner, much higher sensitivity can be obtained than when introducing the sample using only a pump.

FIG. 4 shows the relationship between the flow rate of argon gas for sample transportation and sensitivity. A flow rate of 0 indicates liquid delivery by only the pump. It can be seen that if the flow rate of argon gas is too high, the speed at which the sample is introduced into the manifold is too fast, and the sensitivity actually decreases. By setting the argon gas flow rate optimally in this way,
Sensitivity can be improved by more than 5 times compared to using only a pump.

According to one embodiment of the present invention, highly sensitive and rapid analysis can be performed with a small amount of sample, and at the same time, by changing the quantitative coil 17, the amount of sample can be changed as desired. Furthermore, in the conventional example, the sensitivity sometimes changed depending on the sample liquid feeding speed. In this method, a constant amount of sample is always introduced at a constant speed, which improves accuracy.

FIG. 5 shows a modification of the present invention, which differs from FIG. 1 in that a start switch 27, a first timer 28, and a second timer 29 are added.
The hydride generator shown in FIG. 1 is designated as 25,
Three or four switching valves among them are shown as a valve unit 26. The sample 6 is placed, and the start switch 27 is pressed to start the first timer 28 when the sample starts to be fed. 1st timer 28
The time is set to be sufficient for the sample to fill the metering coil. The capacity of the metering coil is replaceable, so by changing the capacity, the first
The set time of the timer 28 will also be changed as necessary.

When the time set in the first timer 28 has elapsed (the metering coil is filled with the sample), the second timer 29 starts, and at the same time the flow paths of each valve in the valve unit 26 are switched, the sample is injected, and a reaction occurs. , atomic absorption spectrometry is performed. Second timer 29
The time required for their completion is set. When the set time of the second timer 29 ends, it returns to the initial state. At the same time, this second timer 2
At the start of step 9 (when the valves are switched), a start signal to start signal processing is also transmitted to the atomic absorption spectrophotometer 1. Thereby, the calculation (peak height or peak area) of the obtained atomic absorption signal is also automatically performed. By having these functions, when combined with a sampler that automatically exchanges samples, automatic measurement can be performed by automatically obtaining a start signal from the sampler (having the same function as the start switch 27). It becomes possible.

In this embodiment, the switching of the switching valve for switching the flow path is performed automatically, and the calculation of the atomic absorption signal is also automated, thereby improving accuracy and
This has the effect of simplifying operations.

〔Effect of the invention〕

According to the present invention, it is possible to perform highly sensitive measurement of reductive vaporizable elements.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of an embodiment of the present invention, and FIG.
The figure is a diagram explaining the switching state of the valve in the first embodiment, FIG. 3 is a diagram also explaining the valve state at the time of sample injection, FIG. 4 is a diagram showing the relationship between gas flow rate and absorbance, and FIG. FIG. 2 is a diagram showing a schematic configuration of another embodiment of the present invention. 1... Atomic absorption photometer, 2... Atomization section, 3...
...Reducing agent (sodium borohydride), 4...Acid (hydrochloric acid), 5...Carrier (potassium iodide), 6...
Sample, 7, 8, 9, 10...liquid pump, 11...
...Manifold, 12...Mixing chamber,
16...Bypass, 17...Quantity coil, 18,
19, 20, 21...Switching valve, 24...Gas connection part, 27...Start switch, 28, 29
...Timer.

Claims (1)

[Claims] 1 Reduce the test element in the sample to a hydride,
In an analyzer that introduces this hydride into an atomization part and measures it, a mixing part where an acid solution and a reducing agent solution are constantly supplied and hydrogen is generated, a sample measuring part which weighs a certain amount of the sample, A reductive vaporizable element analysis apparatus characterized in that it is provided with pressurized inert gas supply means for introducing the sample from the sample measuring section into the mixing section.