Green detection method for trace heavy metal antimony in water

Abstract

The invention relates to the technical field of water quality detection, and discloses a green detection method for trace heavy metal antimony in water. Air is used as a gas source, low-concentration ozone gas is generated through high-voltage corona, meanwhile, ozone is activated through ultraviolet radiation to generate active oxygen free radicals, Sb (III) in water is synergistically and efficiently oxidized into Sb (V), and detection of high-toxicity Sb (III) and waste liquid discharge are avoided. According to the method, the Sb (V) is enriched and concentrated by adopting an ultrasonic-assisted malachite green-liquid-liquid microextraction technology, so that the use of organic reagents can be effectively reduced, the risk in the extraction process and the waste liquid treatment cost are reduced, and the enrichment factor and the detection sensitivity are improved. According to the invention, total antimony (TSb) and free antimony valence state distribution can be determined by using a differential method. The method has the advantages of being environmentally friendly, rapid in detection, low in cost, mild in reaction condition and the like, and can effectively solve many defects of an existing Sb (III) detection method.

Description

Technical Field

[0001] The present invention relates to the technical field of water quality detection, in particular to a green detection method for trace heavy metal antimony in water and UV / O3 constant temperature synergistic reaction equipment, and in particular to a green detection method for determining trace heavy metal antimony in water based on UV / O3 synergistic oxidation-malachite green-liquid-liquid microextraction-spectrophotometry. Background Art

[0002] Antimony (Sb) is one of the commonly used heavy metal elements and is also a toxic element to the human body. Antimony and its compounds induce diseases by inhibiting the activity of enzymes related to ATP production in the body. Even if the dose of antimony exposed to the environment is low, long-term exposure will still cause irreversible damage to the liver and increase the risk of liver cancer; in addition, a large amount of antimony and its compounds in a short period of time may even induce heart diseases such as myocarditis. However, antimony plays an important role in the manufacturing industry, and its demand has increased sharply with social development. In the process of antimony mining, the production of downstream products and the scrapping process, a large amount of antimony-containing substances will be produced. These substances will cause damage to groundwater and surface water through soil runoff under the vertical rapid penetration in the soil. Therefore, the detection and early warning of various forms of antimony and total antimony in water are of great practical significance for ensuring ecological environmental safety and human health.

[0003] There are many methods for detecting antimony in water, which can be roughly divided into atomic fluorescence spectrometry (AFS), atomic absorption spectrometry (AAS), inductively coupled plasma mass spectrometry (ICP-MS), electrochemical analysis and spectrophotometry. Among them, AFS, AAS, ICP-MS and other methods have high detection accuracy and low detection limit, but the instruments used are expensive and require high sample pretreatment. In the process of using electrochemical analysis, factors such as the influence of coexisting ions and the state of the electrode surface must be considered. The uncertainty of the electrode state limits the application potential of this method in continuous detection. The traditional photometric detection method has many problems such as complex pretreatment process operation (reduction, gasification, expulsion, washing, absorption, color development, etc.), danger (producing colorless and highly toxic antimony hydrogen - SbH3), adding a wide variety of chemical reagents (more than 10 kinds), potential secondary pollution in the detection process, and failure to determine the valence distribution of free antimony. In addition, it was found that most detection methods are based on the detection of Sb(III), and the discharged waste liquid or waste gas contains a large amount of Sb(III), which is much more toxic than Sb(V), and also brings certain pressure to the environment. Therefore, it is of great practical significance to develop a new detection method for antimony in water that is safe, environmentally friendly, economical, efficient and green. Summary of the invention

[0004] The first purpose of the present invention is to propose a green detection method for determining trace heavy metal antimony in water based on UV / O3 synergistic oxidation-malachite green-liquid-liquid microextraction-spectrophotometry, which uses ultraviolet irradiation to activate O3 to produce hydroxyl radicals, superoxide radicals, hydrogen peroxide and other strong oxidizing substances to synergistically oxidize the highly toxic Sb(III) in the water, and then uses malachite green-liquid-liquid microextraction technology to color and enrich and concentrate the Sb(V) generated by oxidation, and finally accurately determines the Sb(V) concentration (total antimony) in the water by ultraviolet spectrophotometry, and uses the difference method (respectively measuring the Sb(V) concentration before and after the synergistic oxidation treatment and calculating the difference) to obtain the valence distribution of free antimony. This method is green and environmentally friendly, has a fast detection speed, low detection cost, and mild reaction conditions, and can solve many deficiencies in existing Sb(III) detection methods. Another purpose of the present invention is to propose a UV / O3 constant temperature synergistic reaction device used in the above method.

[0005] The present invention provides a green detection method for trace heavy metal antimony in water, which mainly comprises the following steps:

[0006] (1) Cooperative oxidation: Pour the blank, standard solution or water sample to be tested into a jacketed bubbling reactor for sufficient UV / O3 synergistic oxidation.

[0007] (2) Color extraction: Take out the oxidized solution and perform complex color development and liquid phase microextraction on the solution according to the malachite green-liquid microextraction method.

[0008] (3) Photometric detection: Take out the organic phase solution after extraction and perform spectrophotometric detection on it.

[0009] (4) Establishing the Sb(V) working curve: The Sb(V) working curve is obtained by linearly fitting the Sb(III) concentration value of the standard sample (standard solution sample) and the average net absorbance obtained according to steps (1), (2), and (3).

[0010] (5) Sb(V) detection: The water sample to be tested is processed according to steps (1), (2) and (3) to obtain the net absorbance value of the water sample to be tested, and the net absorbance value is substituted into the working curve established in step (4) to obtain the Sb(V) concentration value in the water sample to be tested.

[0011] Furthermore, the specific process of step (1) is as follows:

[0012] (a) Prepare potassium antimony tartrate standard solutions of different concentrations, add hydrochloric acid or sodium hydroxide to the standard solutions to adjust the pH of the solutions, and prepare the solutions to be oxidized; the amount of the standard solutions used is 38N42mL. Adjust the pH of the solution to 7.0N9.0.

[0013] Most preferably, standard solutions of potassium antimony tartrate with different concentrations are prepared respectively, 40 mL of the standard solution is taken into a beaker, and the pH value of the solution is adjusted to 8 with hydrochloric acid or sodium hydroxide to prepare the solution to be oxidized.

[0014] (b) Turn on the constant temperature magnetic stirring device, set the reaction temperature to 30-40°C (most preferably 35°C), and turn on the circulating water pump at the same time to circulate the water in the constant temperature magnetic stirrer through the outer jacket of the jacketed bubbling reactor. After the temperature in the constant temperature magnetic stirrer is constant, turn on the ozone generator, adjust the air intake to 0.3L / min, pour the solution to be oxidized through the liquid inlet of the jacketed bubbling reactor and turn on the ultraviolet lamp for oxidation reaction for 10-20min (most preferably 15min). After the oxidation is completed, add a quencher, which is one or a mixture of two or more of methanol (MeOH), tert-butyl alcohol (TBA), benzoquinone (BQ), and furfuryl alcohol (FFA), and stir and let stand for 5-15min (most preferably 10min).

[0015] Furthermore, the specific process of step (2) is as follows:

[0016] Take an appropriate amount of the oxidized solution in a centrifuge tube, add 3-3.66 mL of hydrochloric acid solution to adjust the pH value of the oxidized solution, add deionized water to the volume, continue to add 300-500 μL of malachite green standard solution to the centrifuge tube for complexation reaction, and shake vigorously for 25-35 seconds; after the shaking is completed, add a small amount of chlorobenzene, and then emulsify in an ultrasonic cleaner for 15-25 seconds; put the centrifuge tube into a centrifuge and centrifuge at a speed of 3000N4000 r / min for 0.5-1.5 minutes, and take out the organic phase after centrifugation. The concentration of the hydrochloric acid solution is 10-14 mol / L, and the mass concentration of the malachite green standard solution is 0.01%-0.03%.

[0017] Most preferably, 5 mL of the oxidized solution is measured in a centrifuge tube, 3.33 mL of a 12 mol / L hydrochloric acid solution is added to adjust the pH value of the oxidized solution, and then deionized water is added to make up to 10 mL, and 400 μL of a 0.02% malachite green standard solution is added to the centrifuge tube for complexation reaction, and the solution is shaken vigorously for 30 seconds; after the shaking, 0.2 mL of chlorobenzene is added, followed by emulsification treatment in an ultrasonic cleaner for 20 seconds; the centrifuge tube is placed in a centrifuge and centrifuged at a speed of 3500 r / min for 1 minute, and the organic phase is taken out after centrifugation.

[0018] Furthermore, the specific process of step (3) is as follows:

[0019] Using deionized water as a blank, the extracted organic phase was placed in a 700 μL micro-cuvette, and the absorbance was measured at a wavelength of 628 nm to obtain the net absorbance value. Three parallel measurements were performed to obtain the average net absorbance value.

[0020] Furthermore, the jacketed bubbling reactor is cylindrical, made of ordinary glass, and has the following dimensions: height 200-300 mm, inner diameter 30-35 mm, outer diameter 35-40 mm, and wall thickness 2-4 mm. The most preferred reactor dimensions are: height 250 mm, inner diameter 32 mm, outer diameter 38 mm, and wall thickness 3 mm; the outer jacket dimensions are: height 150-250 mm, inner diameter 46-50 mm, and thickness 2-4 mm. The most preferred outer jacket dimensions are: height 200 mm, inner diameter 48 mm, and thickness 3 mm.

[0021] Furthermore, a 15W UV lamp is placed in the center of the jacketed bubbling reactor, the UV wavelength is 254nm, and the UVC intensity at 1m is 37μW / cm 2 , which can ensure that the ultraviolet light can fully irradiate the reaction liquid.

[0022] Furthermore, the ultraviolet lamp is equipped with a quartz tube sheath to protect the ultraviolet lamp. The quartz tube sheath is cylindrical, with a height of 250-300 mm and an outer diameter of 23-25 ​​mm. The most preferred quartz tube sheath is 280 mm in height and 24 mm in outer diameter.

[0023] Furthermore, the ozone generator is an air source high-voltage corona ozone generator, which produces ozone at a concentration of 2%-4% (v / v), about 3% (v / v), and the ultraviolet rays are short-wave ultraviolet rays with a wavelength between 190 and 280 nm.

[0024] Furthermore, the constant temperature magnetic stirring device is connected to a 24V DC circulating water pump, through which water in the constant temperature magnetic stirring device can be passed into the jacket of the jacketed bubbling reactor for circulation to maintain the reaction temperature. The jacketed bubbling reactor, the circulating water pump and the constant temperature magnetic stirring device are all connected by silicone tubes.

[0025] Furthermore, the green detection method for trace antimony in the water sample to be tested comprises the following steps:

[0026] S1: Take the water sample to be tested and adjust the pH value to prepare the solution to be oxidized, and adjust the pH value to between 7.0 and 9.0;

[0027] S2: Under a constant temperature environment, the oxidized solution undergoes an oxidation reaction under the synergistic effect of ozone and ultraviolet rays, and after oxidation, a quencher is added, stirred and allowed to stand to obtain an oxidized standby solution;

[0028] S3: Take the oxidized standby solution, add acid to adjust the pH value and then make it constant, then add the malachite green standard solution to react to form a complex, and then extract, emulsify and separate the organic phase containing the antimony-malachite green complex;

[0029] S4: performing spectrophotometric detection on the organic phase containing the antimony-malachite green complex to determine its absorbance, and obtaining a net absorbance value of the water sample to be tested;

[0030] S5: Finally, the net absorbance value of the water sample to be tested is substituted into a standard solution of known concentration for determination to establish an Sb(V) working curve, and the antimony content in the water sample to be tested is obtained.

[0031] Furthermore, in step S3, concentrated hydrochloric acid is used to adjust the pH value, and the concentration range of the added concentrated hydrochloric acid is 10-14 mol / L. The concentration of the hydrochloric acid solution after the pH value is adjusted is 3.6-4.4 mol / L, preferably 4 mol / L.

[0032] Furthermore, in step S4, the net absorbance value is the difference between the absorbance value obtained by spectrophotometric detection of the organic phase and the absorbance value obtained by detection of a blank solution; the blank solution is deionized water.

[0033] Furthermore, in step S5, the Sb(V) working curve is obtained by linearly fitting the net absorbance values ​​of multiple groups of standard solutions with known gradient concentrations obtained according to steps S1, S2, S3, and S4 using the Sb(III) concentration values ​​and net absorbance values ​​of the standard solutions.

[0034] Furthermore, the net absorbance value is an average net absorbance value obtained by averaging three or more net absorbance values.

[0035] The present invention provides another UV / O3 constant temperature synergistic reaction device used in the green detection process of heavy metal antimony. The UV / O3 constant temperature synergistic reaction device is a device used to provide constant temperature and UV / O3 synergistic oxidation reaction in the green detection process of heavy metal antimony. The UV / O3 synergistic reaction device mainly consists of a jacketed bubbling reactor, an ultraviolet lamp, a circulating water pump, a constant temperature magnetic stirring device, a tail gas absorption device and an ozone generator; wherein the ultraviolet lamp is placed in the center of the jacketed bubbling reactor; the upper part of the jacketed bubbling reactor is connected to the tail gas absorption device through an air outlet, and the bottom is connected to the ozone generator through an air inlet, and the upper and lower parts of the jacketed bubbling reactor are respectively provided with a liquid inlet and a liquid outlet of a solution to be oxidized;

[0036] The upper and lower parts of the outer jacket of the jacketed bubbling reactor are connected to a circulating water pump and a constant temperature magnetic stirring device through a circulating water outlet and a circulating water inlet respectively to form a circulation system to maintain a constant reaction temperature;

[0037] The oxidized solution is poured into a jacketed bubbling reactor for sufficient UV / O3 synergistic oxidation.

[0038] Compared with the prior art, the present invention has the following advantages:

[0039] (1) Using air as the gas source, the high-voltage corona method produces low-concentration ozone gas without adding any chemical oxidizing agents. The degradation product is also harmless oxygen, which does not produce secondary pollution. It is low-cost and environmentally friendly.

[0040] (2) Using ultraviolet irradiation to activate ozone to generate active oxygen free radicals with strong oxidizing ability can synergistically and efficiently oxidize Sb(III). At the same time, the residual oxidant can be effectively removed, reducing the interference with complexation and detection results, and improving the stability of detection;

[0041] (3) Malachite green is used as the complexing agent for Sb(V), which has high sensitivity and strong stability;

[0042] (4) Ultrasonic-assisted liquid-liquid microextraction is used to enrich and concentrate trace Sb(V)-basic dye complexes in water. The organic reagents consumed in the extraction are measured in microliters, which can effectively reduce the amount of organic reagents used, reduce the risks of the extraction process and the cost of waste liquid treatment. At the same time, the enrichment factor is high, which improves its detection accuracy;

[0043] (5) Based on the detection of Sb(V), the detection of highly toxic Sb(III) is avoided. The Sb(V) complex product has low toxicity, and the detection method is safer and less polluting. At the same time, the differential method can be used to determine both total antimony (TSb) and the valence distribution of free antimony (Sb(III), Sb(V)).

[0044] (6) The detection uses low-cost accessories or instruments such as ultraviolet lamps, ozone generators and spectrophotometers, which are simple to operate, have low operation and maintenance costs, and are cost-effective. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 This is a diagram of the Sb(III) synergistic oxidation device based on UV / O3 advanced oxidation technology of the present invention;

[0046] Figure 2 It is the Sb(V) working curve of the present invention.

[0047] In the figure:

[0048] 1. Jacketed bubbling reactor; 2. Ultraviolet lamp; 3. Liquid inlet; 4. Jacket; 5. Liquid outlet; 6. Circulating water pump; 7. Constant temperature magnetic stirring device; 8. Tail gas absorption device; 9. Ozone generator. DETAILED DESCRIPTION

[0049] In order to make the public have a thorough understanding of the present invention, the present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments, but it should not be understood as limiting the present invention. The present invention covers any substitution, modification, equivalent method and scheme made on the essence and scope of the present invention, and those skilled in the art can fully understand the present invention without these detailed descriptions. The reagents, materials, etc. used in the following examples can all be obtained from commercial sources.

[0050] like Figure 1-Figure 2 As shown, the Sb(III) synergistic oxidation device diagram based on UV / O3 advanced oxidation technology of the present invention mainly includes a jacketed bubbling reactor 1, an ultraviolet lamp 2, a constant temperature magnetic stirring device 7, a circulating water pump 6 and an ozone generator 9. The ultraviolet lamp 2 is fixed inside the jacketed bubbling reactor 1 with a quartz tube sheath; a liquid inlet 3 is arranged on the upper right side of the jacketed bubbling reactor 1; an air outlet is arranged on the upper left side of the jacketed bubbling reactor 1, and the air outlet is connected to the tail gas absorption device 8; an air inlet is arranged in the middle of the bottom of the jacketed bubbling reactor 1, and the air inlet is connected to the ozone generator 9; a liquid outlet 5 is arranged on the lower right side of the jacketed bubbling reactor 1; a circulating water outlet and a circulating water inlet are arranged on the upper left and lower right of the outer jacket 4 of the jacketed bubbling reactor 1, respectively, and are connected to the constant temperature magnetic stirring device 7 through the circulating water pump 6.

[0051] The jacketed bubbling reactor 1 is cylindrical and made of ordinary glass. The reactor dimensions are: height 250 mm, inner diameter 32 mm, outer diameter 38 mm, and wall thickness 3 mm; the outer jacket 4 dimensions are: height 200 mm, inner diameter 48 mm, and thickness 3 mm.

[0052] The maximum capacity of the jacketed bubbling reactor 1 is about 60 mL.

[0053] The power of UV lamp 2 is 15W, the UV wavelength is 254nm, and the UVC intensity at 1m is 37μW / cm 2 , which can ensure that the ultraviolet light can fully irradiate the reaction liquid.

[0054] The ultraviolet lamp 2 is provided with a quartz tube sheath to protect the ultraviolet lamp. The quartz tube sheath is cylindrical, with a height of 280 mm and an outer diameter of 24 mm.

[0055] The constant temperature magnetic stirring device 7 is connected to a 24V DC circulating water pump 6, and the water in the constant temperature magnetic stirring device 7 can be passed into the jacket 4 of the jacketed bubbling reactor 1 through the circulating water pump 6 to circulate to maintain the reaction temperature. The jacketed bubbling reactor 1, the circulating water pump 6 and the constant temperature magnetic stirring device 7 are all connected by silicone tubes.

[0056] The green detection method for determining trace antimony in water based on UV / O3 synergistic oxidation-malachite green-liquid-liquid microextraction-spectrophotometry includes the following steps:

[0057] (1) Cooperative oxidation: Pour the standard solution or the water sample to be tested into the jacketed bubbling reactor 1 for sufficient UV / O3 cooperative oxidation.

[0058] (a) Weigh 0.5039 g of potassium antimony tartrate into a beaker, dissolve it in deionized water, transfer it to 100 mL, and dilute it to 1000 mg / L with deionized water to prepare a Sb(III) stock solution;

[0059] (b) Prepare Sb(III) standard solutions of different concentrations by diluting the Sb(III) stock solution with deionized water. Take 40 mL of the standard solution in a beaker and adjust the pH to 7 with hydrochloric acid or sodium hydroxide to prepare the solution to be oxidized;

[0060] (c) Turn on the constant temperature magnetic stirring device 7, set the reaction temperature to 35°C, and turn on the circulating water pump 6 at the same time, so that the water in the constant temperature heating magnetic stirrer 7 circulates through the outer jacket 4 of the jacketed bubbling reactor 1. After the temperature in the constant temperature magnetic stirrer 7 is constant, turn on the air source ozone generator 9, adjust the air intake to 0.3L / min, and then pour the solution to be oxidized through the liquid inlet 3 of the jacketed bubbling reactor 1 and turn on the ultraviolet lamp 2 to carry out the oxidation reaction for 15min. After the oxidation is completed, add the quencher methanol, stir and let it stand for 10min.

[0061] (2) Color extraction: Take out the oxidized solution and perform complex color development and liquid phase microextraction on the solution according to the malachite green-liquid microextraction method.

[0062] (a) Use an electronic balance to weigh 0.0200 g of malachite green (MG) in a beaker, dissolve it in an appropriate amount of deionized water, transfer it to a 100 mL brown volumetric flask, make up to volume, and shake well to prepare a malachite green standard solution with a mass concentration of 0.02%;

[0063] (b) 5 mL of the oxidized solution was measured and placed in a centrifuge tube. 3.33 mL of 12 mol / L hydrochloric acid solution was added to adjust the pH value of the oxidized solution to 4 mol / L hydrochloric acid solution, and then deionized water was added to make the volume to 10 mL. 400 μL of 0.02% malachite green standard solution was added to the centrifuge tube for complexation reaction, and the solution was shaken vigorously for 30 seconds. After the shaking, 0.2 mL of chlorobenzene was added, and then the solution was emulsified in an ultrasonic cleaner for 20 seconds. The centrifuge tube was placed in a centrifuge and centrifuged at 3500 r / min for 1 minute. The organic phase was taken out after centrifugation.

[0064] (3) Photometric detection: Take out the organic phase solution after extraction and perform spectrophotometric detection on it.

[0065] With deionized water as blank, the extracted organic phase was placed in a 700 micro-volume cuvette and the absorbance was measured at a wavelength of 628 nm to obtain the net absorbance value. Three parallel measurements were performed to obtain the average net absorbance value.

[0066] (4) Establishing the Sb(V) working curve: The Sb(V) working curve y = 0.0091x + 0.0155 (R 2 =0.9943, R2 is the coefficient of determination. The closer the value is to 1, the better the fit between the model and the data, which means that the model can explain most of the data variability). x represents the concentration of Sb(V) in μg / L, and y is the net absorbance. The prepared standard solution Sb(III) is completely oxidized after 15 minutes to the concentration of Sb(V). Figure 2 The horizontal axis records the Sb(V) concentration value.

[0067] (5) Sb(V) detection: The water sample to be tested is processed according to steps (1), (2) and (3) to obtain the net absorbance value of the water sample to be tested, and the net absorbance value is substituted into the working curve established in step (4) to obtain the Sb(V) concentration value in the water sample to be tested.

[0068] The basic principle of malachite green-liquid-liquid microextraction-spectrophotometry is as follows:

[0069] After malachite green is dissolved in water, MG+ reacts with [SbCl6]- in a high-concentration hydrochloric acid medium to form an electrically neutral blue complex. This complex has a characteristic absorbance under light irradiation of a specific wavelength (usually in the range of 620-640nm). The generated blue complex is transferred from the aqueous phase to the organic phase by liquid-liquid microextraction to facilitate enrichment measurement. The absorbance of the extraction phase is measured at a specific wavelength using a spectrophotometer. The absorbance is proportional to the antimony content in the sample. The linear relationship between absorbance and antimony concentration is established based on the following mathematical expression of the Lambert-Beer law (1).

[0070] A=Kbc (1)

[0071] Where A is absorbance; K is molar absorption coefficient; b is optical path length; and c is the molar concentration of the sample.

[0072] The basic principle of antimony detection based on malachite green-liquid-liquid microextraction-spectrophotometry in the present invention is to establish a linear model between absorbance and antimony concentration. A series of potassium antimony tartrate solutions with known antimony concentrations were prepared according to national standards, and oxidation, liquid-liquid microextraction and photometric detection were performed respectively. The absorbance A of the blank sample was measured and recorded. bThe absorbance of the standard sample A s , the difference between the two is calculated as the net absorbance Ar, and the calculation formula is shown in formula (2).

[0073] A r =A s -A b (2)

[0074] The Sb(III) stock solution was used to prepare standard solutions with concentrations of 1, 2, 5, 10, 15, 20, 25, and 30 μg / L, and the standard solutions were determined according to the detection method based on UV / O3 synergistic oxidation-malachite green-liquid-liquid microextraction-spectrophotometry. The blank absorbance was measured after replacing the sample with deionized water, and the net absorbance A of each standard solution was calculated according to formula (2): r , the test results are shown in Table 1.

[0075] Table 1 Absorbance measured after Sb(III) oxidation

[0076]

[0077] According to the data in Table 1, the working curve of Sb(V) after Sb(III) is treated with UV / O3 oxidation is drawn, as shown in Figure 2 The working curve equation of Sb(V) after UV / O3 oxidation is obtained by fitting the data in Table 1 in the range of 1 to 30 μg / L: y=0.0091x+0.0155(R 2 =0.9943), where x represents the concentration of Sb(V) in μg / L, and y is the net absorbance measured after UV / O3 oxidation treatment.

[0078] Deionized water was used instead of the sample, and 8 blank parallel determinations were performed according to the UV / O3 synergistic oxidation-malachite green-liquid-liquid microextraction-spectrophotometry. The standard deviation and detection limit of the 8 blank determinations were calculated. The blank experiment results are shown in Table 2.

[0079] Table 2 Blank test results

[0080]

[0081]

[0082] According to the method characteristic index determination method stipulated in my country's national ecological environment standard HJ 168-2020, the method detection limit MDL based on UV / O3 synergistic oxidation-malachite green-liquid-liquid microextraction-spectrophotometry can be calculated as MDL=2.998*0.1070=0.3208μg / L.

[0083] To further verify the accuracy of this method, Sb(III) standard solutions with concentrations of 6 and 24 μg / L were prepared, and six parallel measurements were carried out according to the detection method based on UV / O3 synergistic oxidation-malachite green-liquid-liquid microextraction-spectrophotometry. The precision and correctness of the detection method were calculated. The results are shown in Table 3.

[0084] Table 3 Accuracy test

[0085]

[0086]

[0087] As shown in Table 3, the precision of the detection method is 1.63%, and the correctness is 0.64%, which has good accuracy.

[0088] Although the embodiments are described and explained separately above, they involve some common technologies. For those of ordinary skill in the art, it can be understood that these embodiments can be modified without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the attached claims and their equivalents. The above only describes the preferred embodiments of the present invention, but it cannot be understood as a limitation on the claims. The present invention is not limited to the above embodiments, and its specific structure is allowed to be changed. In short, all changes made within the scope of protection of the independent claims of the present invention are within the scope of protection of the present invention.

Claims

1. A green detection method for trace heavy metal antimony in water, characterized by: The following steps are involved: S1: Take a fixed volume of the water sample to be tested and adjust the pH value to prepare a solution to be oxidized, and adjust the pH value to between 7.0 and 9.0; S2: Under a constant temperature environment, the oxidized solution undergoes an oxidation reaction under the synergistic effect of ozone and ultraviolet rays, and after oxidation, a quencher is added, stirred and allowed to stand to obtain an oxidized standby solution; S3: Take a fixed volume of the oxidized standby solution, add acid to adjust the pH value and then make it constant, then add malachite green standard solution to react to form a complex, then extract, emulsify and separate the organic phase containing the antimony-malachite green complex; S4: performing spectrophotometric detection on the organic phase containing the antimony-malachite green complex to determine its absorbance, and obtaining a net absorbance value of the water sample to be tested; S5: Finally, the net absorbance value of the water sample to be tested is substituted into a standard solution of known concentration for determination to establish an Sb(V) working curve, and the antimony content in the water sample to be tested is obtained.

2. The green detection method for trace heavy metal antimony in water according to claim 1, characterized in that: In step S2, the quencher is selected from one of methanol (MeOH), tert-butyl alcohol (TBA), benzoquinone (BQ), furfuryl alcohol (FFA) or a mixture of two or more thereof.

3. The green detection method for trace heavy metal antimony in water according to claim 1, characterized in that: In step S2, the ozone concentration is 2%-4% by volume, and the ultraviolet rays are short-wave ultraviolet rays with a wavelength between 190 and 280 nm.

4. The green detection method for trace heavy metal antimony in water according to claim 1, characterized in that: In step S3, the mass concentration of the malachite green standard solution is selected from a concentration between 0.01% and 0.03%; the strong acid is concentrated hydrochloric acid, the concentration range of the added concentrated hydrochloric acid is 10 to 14 mol / L, and the concentration of the hydrochloric acid solution after adjusting the pH value is 3.6-4.4 mol / L.

5. The green detection method for trace heavy metal antimony in water according to claim 1, characterized in that: The reaction temperature of the constant temperature environment in step S2 is selected to be a temperature value between 30 and 40°C; In step S3, the complexing reaction time is 25 to 35 seconds; the extractant during extraction is chlorobenzene; an ultrasonic cleaner is used for emulsification, and the emulsification time is 15 to 25 seconds; a centrifuge is used for separation, and the centrifuge is centrifuged at a speed of 3000 to 4000 r / min for 0.5 to 1.5 minutes.

6. The green detection method for trace heavy metal antimony in water according to claim 1, characterized in that: In step S4, the net absorbance value is the absorbance value obtained by spectrophotometric detection of the organic phase; the difference between the obtained absorbance value and the absorbance value obtained by the blank solution detected according to steps S1, S2, S3, and S4; The blank solution was deionized water.

7. The green detection method for trace heavy metal antimony in water according to claim 1, characterized in that: In step S5, the standard solution is potassium antimony tartrate standard solution; and the absorbance is measured at a wavelength of 628 nm.

8. The green detection method for trace heavy metal antimony in water according to claim 1, characterized in that: In step S5, the Sb(V) working curve is obtained by linearly fitting the net absorbance values ​​of multiple groups of standard solutions with known gradient concentrations obtained according to steps S1, S2, S3, and S4 using the Sb(III) concentration values ​​and net absorbance values ​​of the standard solutions.

9. The green detection method for trace heavy metal antimony in water according to claim 1, 6 or 8, characterized in that: The net absorbance value is an average net absorbance value obtained by averaging three or more net absorbance values.

10. A UV / O3 constant temperature synergistic reaction device used in the green detection process of heavy metal antimony; characterized by: The UV / O3 constant temperature synergistic reaction equipment is a device for providing a constant temperature, UV / O3 synergistic oxidation reaction in the green detection process of heavy metal antimony. The UV / O3 synergistic reaction equipment mainly consists of a jacketed bubbling reactor (1), an ultraviolet lamp (2), a circulating water pump (6), a constant temperature magnetic stirring device (7), a tail gas absorption device (8) and an ozone generator (9); wherein the ultraviolet lamp (2) is placed at the center of the jacketed bubbling reactor (1); the upper part of the jacketed bubbling reactor (1) is connected to the tail gas absorption device (8) through an air outlet, and the bottom is connected to the ozone generator (9) through an air inlet, and the upper and lower parts of the jacketed bubbling reactor (1) are also respectively provided with a liquid inlet (3) and a liquid outlet (5) of the solution to be oxidized; The upper and lower parts of the outer jacket (4) of the jacketed bubbling reactor (1) are connected to a circulating water pump (6) and a constant temperature magnetic stirring device (7) through a circulating water outlet and a circulating water inlet, respectively, to form a circulation system to maintain a constant reaction temperature; The solution to be oxidized is poured into a jacketed bubbling reactor (1) for sufficient UV / O3 synergistic oxidation.

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