CN107702977B

CN107702977B - Dissolving titanium pyrophosphate by microwave digestion method

Info

Publication number: CN107702977B
Application number: CN201710888438.1A
Authority: CN
Inventors: 王琳琨; 唐继鲜; 刘艳; 曹生硕
Original assignee: CDGM Glass Co Ltd
Current assignee: CDGM Glass Co Ltd
Priority date: 2017-09-27
Filing date: 2017-09-27
Publication date: 2020-12-01
Anticipated expiration: 2037-09-27
Also published as: CN107702977A

Abstract

The invention belongs to the technical field of analysis, and particularly relates to a microwave digestion method for dissolving titanium pyrophosphate. The invention aims to solve the technical problem of providing a method for dissolving titanium pyrophosphate by microwave digestion. The method has the advantages of high efficiency, high speed, small reagent consumption, small environmental pollution and the like, improves the efficiency by adopting the method to dissolve the samples, is particularly suitable for measuring the samples in batches, and meets the requirements of scientific research and production.

Description

Dissolving titanium pyrophosphate by microwave digestion method

Technical Field

The invention belongs to the technical field of analysis, and particularly relates to a microwave digestion method for dissolving titanium pyrophosphate.

Background

Titanium Pyrophosphate (TiP)₂O₄) Is white crystal, cubic system, and has a density of 3.106g/cm³And is insoluble in water. The chemical property is relatively stable, and the product is not dissolved in hydrochloric acid, nitric acid, sulfuric acid, perchloric acid or the mixed acid of several acids at normal temperature. However, the actual production and scientific research requirements require quantitative tests on the impurity elements contained in the titanium pyrophosphate, and the detection of the titanium pyrophosphate is mainly divided into a pretreatment part and a quantitative test part. The pretreatment work directly influences the detection result, and the pretreatment method is a decisive factor for analyzing the accuracy of detection. Therefore, a proper sample dissolving method must be found to completely dissolve the titanium pyrophosphate, so as to ensure the accuracy of the next detection.

Disclosure of Invention

The invention provides a pretreatment method of titanium pyrophosphate, namely a method for dissolving titanium pyrophosphate. The method can completely, quickly, efficiently and safely dissolve the titanium pyrophosphate, thereby ensuring the accuracy of subsequent detection.

The technical scheme for solving the technical problems comprises the following steps: dissolving titanium pyrophosphate by adopting a microwave digestion method.

Specifically, in the microwave digestion method for dissolving titanium pyrophosphate, hydrofluoric acid is used as a solvent.

Preferably, 5 to 10mL of hydrofluoric acid is added per 0.5 to 1.0g of titanium pyrophosphate dissolved in the microwave digestion method. The mass concentration of the hydrofluoric acid is 36-38%.

Preferably, the microwave digestion method dissolves titanium pyrophosphate, and the digestion reaction temperature is 150-160 ℃.

Preferably, the microwave digestion method dissolves titanium pyrophosphate, and the digestion reaction time is 30-50 min.

The invention has the beneficial effects that:

1. the dissolution speed is high. By adopting the method of the invention to dissolve titanium pyrophosphate, the sample can be completely dissolved in half an hour.

2. Less solvent consumption and low blank position. Only 5mL of hydrofluoric acid is needed to digest 0.5g of titanium pyrophosphate, only a fraction of the amount of acid used in the conventional method. The reason is that the closed digestion acid can not be volatilized and lost, and the acid does not need to be added continuously for keeping the volume of the acid, so that the reagent is saved, the blank value of the analysis is greatly reduced, the interference of impurity elements brought by the reagent is reduced, and the blank value is obviously reduced.

3. The reagent volatilization loss and sample contamination are avoided, and the analysis accuracy and precision are improved. And a closed digestion tank is adopted, so that the loss of volatile components formed in the digestion process of the sample is avoided, and the accuracy of a measurement result is ensured. And the mutual pollution among samples and the pollution of the external environment are avoided, and the method is suitable for trace and ultra-pure analysis and the detection of volatile elements. The microwave digestion system can display three parameters of pressure, temperature and time in the closed tank in the reaction process in real time. The method can be accurately controlled, the reaction repeatability is good, and the accuracy and the precision are improved.

4. The labor intensity is reduced, and the working environment is improved. Acid is boiled on the electric hot plate, the sample is digested, the volatile acid is greatly reduced in the closed tank, and the working environment of the analyst is effectively improved. Because the speed of digesting the sample is accelerated, the analysis time is shortened, the accuracy and the precision of analysis are improved, the labor intensity is obviously reduced, and the working efficiency is improved.

5. The power consumption is saved, and the analysis cost is reduced. The microwave closed digestion not only saves reagents, but also saves electric energy. Such as: digesting 0.2 g of sample, heating by 800W microwave, and digesting in only 8 minutes. And a 2.0KW electric heating plate is used for heating for dozens of hours, so that the reaction time is greatly shortened, and the analysis cost is reduced.

Detailed Description

In order to completely dissolve the titanium pyrophosphate, the inventor of the invention has found through a large number of screening tests that the samples are not completely dissolved by adopting a platinum crucible electric furnace dissolution method, an electric heating plate digestion method and an autoclave closed digestion method, and finally the titanium pyrophosphate can be quickly and completely dissolved by adopting a microwave digestion method. Part of the screening experiments were as follows:

test example 1 screening of sample dissolving method

In order to find out a method for dissolving titanium pyrophosphate, the inventor has made a lot of comparative experiments, and compared the sample weighing amount, the dissolving amount, the reaction temperature, the reaction time and the reaction effect according to the nature of the solvent and the characteristics of each sample dissolving method, and part of the experimental data are as follows:

TABLE 1

TABLE 2

As can be seen from the above tables 1 and 2, the electric furnace dissolution method, the electric heating plate digestion method and the autoclave closed digestion method have longer reaction time and lower reaction efficiency, and can not achieve the purpose of completely dissolving the sample; only by the microwave digestion method, the titanium pyrophosphate can be completely dissolved. Test example 2 screening of test conditions

On the basis of establishing a sample dissolving method, the inventor starts from a plurality of parameters influencing the microwave digestion reaction rate and focuses on researching the influence of the reaction time, the reaction temperature and the reagent dosage on the reaction effect so as to achieve the purposes of high efficiency, rapidness, less reagent dosage, small environmental pollution and the like. Some experimental data are as follows:

(1) reaction time

TABLE 3

As can be seen from Table 3, it took at least 30min to dissolve the 0.5g sample. In order to ensure complete dissolution and economic benefit, the sample dissolution time is preferably 30-50 min.

(2) Reaction temperature

TABLE 4

Reaction temperature/. degree.C	160	150	140	130	120
						Sample weighing (g)	0.5	0.5	0.5	0.5	0.5
Amount of hydrofluoric acid (mL)	10	10	10	10	10
						Reaction time (h)	0.5	0.5	0.5	0.5	0.5
Amount of dissolved sample (g)	Completely dissolve	Completely dissolve	Is not completely dissolved	Is not completely dissolved	Is not completely dissolved

As can be seen from Table 4, the sample dissolution temperature needs to be controlled to be above 150 ℃ to be able to be completely dissolved in a short time, so in order to ensure complete dissolution and save energy, the reaction temperature is preferably controlled to be 150-160 ℃.

(3) Amount of hydrofluoric acid used

According to the volume of the microwave digestion tank, the dosage of the reagent cannot exceed two thirds of the total volume, but because hydrofluoric acid has strong corrosivity and causes serious pollution to the environment, in principle, the same dissolving effect is achieved, the smaller the dosage of the hydrofluoric acid is, the better the dosage of the hydrofluoric acid is, in order to further determine the dosage range of the reagent, the inventor carries out a comparative experiment, and partial data are as follows:

TABLE 5

As is apparent from Table 5, when the amount of titanium pyrophosphate is 0.5g, the hydrofluoric acid content is 5mL or more, and the complete dissolution at 150 ℃ for 30min is ensured, so that 0.5g of the sample can be completely dissolved by using 5mL or more of hydrofluoric acid. In order to ensure complete and economical dissolution, it is preferable to add 5 to 10mL of hydrofluoric acid per 0.5 to 1.0g of titanium pyrophosphate.

The microwave digestion instrument adopted in the embodiment of the invention is purchased from American CEM Mars 240/50(907510), and the model of the high-throughput closed microwave digestion instrument is MD 3010. The microwave digestion instrument has the advantages of convenience, rapidness, high efficiency, small reagent dosage, low blank and no pollution, and the batch processing quantity of the instrument reaches 40 independent closed samples.

Example 1

0.5g of titanium pyrophosphate is weighed into a polytetrafluoroethylene digestion tank, 5mL of hydrofluoric acid with the mass concentration of 36% is added, and the tank is covered and sealed. And (3) placing the digestion tank in a microwave digestion instrument, setting the temperature at 150 ℃, reacting for 30min, operating a digestion program, cooling, taking out the digestion tank, and completely dissolving the sample. The system was a clear, transparent solution. As a detection sample, the detection accuracy can be ensured.

Example 2

1g of titanium pyrophosphate is weighed into a polytetrafluoroethylene digestion tank, 10mL of hydrofluoric acid with the mass concentration of 38% is added, and the tank is covered and sealed. And (3) placing the digestion tank in a microwave digestion instrument, setting the temperature at 160 ℃, reacting for 30min, operating a digestion program, cooling, taking out the digestion tank, and completely dissolving the sample. The system was a clear, transparent solution. As a detection sample, the detection accuracy can be ensured.

Claims

1. A method for digesting titanium pyrophosphate by microwave adopts hydrofluoric acid as a solvent; adding 5-10 mL of hydrofluoric acid into every 0.5-1.0 g of titanium pyrophosphate; the mass concentration of the hydrofluoric acid is 36-38%; the digestion reaction temperature is 150-160 ℃; the digestion reaction time is 30-50 min.