CN113324972B - A kind of quantitative analysis method of formaldehyde in water environment - Google Patents

Abstract

The invention discloses a quantitative analysis method for formaldehyde in a water environment, and belongs to the technical field of environment detection. The quantitative analysis method comprises the following steps: preparing a solid surface enhanced Raman scattering substrate by using a perovskite-like composite material modified by gold-silver nano alloy as a base material; preparing formaldehyde standard solutions with different concentrations, detecting by adopting the prepared solid surface enhanced Raman scattering substrate, and drawing a standard curve according to the peak value of the characteristic Raman shift position of the obtained standard solutions with different concentrations and the concentration of the formaldehyde standard solution; and detecting the water sample subjected to pretreatment by using the obtained solid surface enhanced Raman scattering substrate, comparing the detected water sample with the standard curve to obtain the concentration of formaldehyde in the water sample, and verifying the accuracy of the analysis method by using a high performance liquid chromatography. The method has the characteristics of high anti-interference capability, high sensitivity, stable signal, good reproducibility and the like for trace detection of a water sample, and can specifically select formaldehyde.

Description

A kind of quantitative analysis method of formaldehyde in water environment

technical field

The invention relates to a quantitative analysis method for formaldehyde in a water environment, and belongs to the technical field of environmental detection.

Background technique

Formaldehyde is a common environmental pollutant that is often present in the atmosphere and water. Since water is an indispensable resource for human beings, environmental water is often polluted by factory waste and domestic waste. Among many pollutants, formaldehyde is a very common pollutant, and excessive formaldehyde will cause serious damage to human health. threaten. In addition, formaldehyde is a precursor of some polymeric materials. In order to reduce costs, some unscrupulous manufacturers directly discharge the remaining formaldehyde raw materials in the production process into the water source, which greatly increases the risk of water pollution by formaldehyde. Therefore, it is of great significance to establish an accurate, efficient and economical method for the analysis of formaldehyde in water environment.

At present, the detection methods of formaldehyde in the domestic water environment are mainly high performance liquid chromatography and ultraviolet spectrophotometry, but there are many problems such as time-consuming and high cost, which cannot meet the needs of rapid detection. Surface-enhanced Raman scattering (SERS) has many advantages, such as high sensitivity, strong specificity, rapid detection, etc., and it is easy to achieve rapid detection. However, in the actual detection process, the reproducibility and selectivity of SERS analysis and detection are lacking, and the key to improving the reproducibility and selectivity of SERS analysis and detection is to choose a suitable SERS-enhancing substrate.

The currently commonly used SERS-enhancing substrates are noble metal nanoparticles, which have the characteristics of simple preparation, low price, and obvious SERS-enhancing effect. detection. Therefore, it is very important to develop a SERS-enhanced substrate with good stability, high selectivity and easy preservation.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a quantitative analysis method of formaldehyde in water environment, aiming to realize the quantitative detection of formaldehyde in water samples by SERS, and the detection method of the present invention has ideal selectivity and reproducibility.

The present invention first provides a preparation method of a solid-state surface-enhanced Raman scattering substrate, the method comprising:

(1) Preparation of perovskite-like nanomaterials: after mixing lead nitrate solution and bismuth nitrate solution, ethylene glycol and ionic liquid 1-hexadecyl-3-methylimidazolium bromide are added, and after mixing uniformly, at 120- React at 160°C for 18-30h, then wash and dry to prepare perovskite-like nanomaterials;

(2) Preparation of gold-silver nanoalloy modified perovskite-like composite material: Disperse the perovskite-like nanomaterial prepared in step (1) into water, heat to boiling after ultrasonic dispersion, add chloroauric acid and silver nitrate solution , continue heating for 5-20min, then add sodium citrate solution, keep boiling for 15-30min, wash and dry after cooling to obtain gold-silver nanoalloy modified perovskite-like composite material;

(3) Preparation of solid-state surface-enhanced Raman scattering substrate: take the gold-silver nanoalloy-modified perovskite-like composite material prepared in step (2) to prepare a dispersion with a concentration of 1.0-3.0 mg mL ^-1 , and filter it On the surface of qualitative filter paper, a solid surface-enhanced Raman scattering substrate can be obtained.

In an embodiment of the present invention, in step (1), the molar ratio of lead nitrate and bismuth nitrate is 1-2:1-2, and lead nitrate and 1-hexadecyl-3-methylimidazole The molar ratio of bromine salt is: 1～2:1～2.

In an embodiment of the present invention, in step (1), the washing is washing with absolute ethanol and ultrapure water for multiple times respectively.

In an embodiment of the present invention, in step (2), the mass ratio of the chloroauric acid and silver nitrate is 1-2:1, and the mass ratio of silver nitrate and perovskite-like nanomaterials is 1:8 ~16.

In one embodiment of the present invention, in step (2), the mass ratio of sodium citrate to perovskite-like nanomaterials is 1.24:1-1.24:2.

In one embodiment of the present invention, the washing is washing with ultrapure water several times.

The second object of the present invention is to provide the solid-state surface-enhanced Raman scattering substrate prepared by the above method.

The 3rd object of the present invention is to provide a kind of quantitative detection method of formaldehyde in water environment, and described method may further comprise the steps:

Step S01 : preparing standard solutions of formaldehyde with different concentrations, and using the above-mentioned solid surface-enhanced Raman scattering substrate for detection, and drawing a standard curve according to the obtained characteristic Raman shift peaks of the different concentrations of formaldehyde and the concentration of the standard solution of formaldehyde;

Step S02 : using the above solid surface-enhanced Raman scattering substrate and detecting the pretreated water sample, and comparing the obtained peak value at the characteristic Raman shift with the standard curve to obtain the concentration of formaldehyde in the water sample.

In an embodiment of the present invention, in step S01, the prepared formaldehyde standard solution can be 20 μg·L ^-1 , 50 μg·L ^-1 , 100 μg·L ^-1 , 200 μg·L ^-1 , 400 μg·L -1 ^{. 1.} The gradient solution of 500 μg·L ^-1 can also be standard solutions of other concentrations. The smaller the prepared concentration gradient, the closer the standard curve that can be obtained is to the real value.

In one embodiment of the present invention, the formaldehyde standard solution or water sample needs to be derivatized before the solid surface-enhanced Raman scattering substrate is detected.

In one embodiment of the present invention, the derivatization comprises the steps of: adding a solution of 4-amino-5-hydrazino-3-mercapto-1,2,4-triazole and hydroxide to a solution containing formaldehyde sodium solution, and then incubate for 10 to 60 min.

In an embodiment of the present invention, the pretreatment steps of the water sample include natural sedimentation, centrifugation, and membrane filtration.

In one embodiment of the present invention, the filter membrane used in the membrane filtration is a commercial 0.22 μm nylon membrane.

In an embodiment of the present invention, the pretreatment of the water sample specifically includes: using natural sedimentation for 12-36 hours, then centrifuging at 5000-7000 rpm for 5-10 minutes, and finally using a 0.22 μm nylon membrane to filter way of processing.

The fourth object of the present invention is to provide the application of the above quantitative detection method in the environmental field.

Beneficial effects of the present invention:

(1) with respect to the prior art, the quantitative analysis method of formaldehyde in the water environment provided by the invention has the anti-interference ability to the detection of formaldehyde in the water sample due to the uniform distribution of solid-state enhanced substrate "hot spots", convenient preparation and good stability It has the characteristics of high sensitivity, stable signal, and good reproducibility, and can have specific selection for formaldehyde.

(2) The preparation method of the solid-state surface-enhanced Raman scattering substrate is simple, fast, low-cost, convenient to carry, and easy to store; the detection limit is low (2.6μg·L ^-1 ), which is more suitable for trace detection; water sample pretreatment The steps are simple and suitable for SERS detection; in addition, due to the high selectivity of the derivatization reagent, the solid-state surface-enhanced Raman scattering substrate has a specific selectivity to formaldehyde within a certain range.

Description of drawings

In order to illustrate the technical solutions of the present invention more clearly, the following briefly introduces the accompanying drawings used in the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention, which are common in the art. As far as technical personnel are concerned, other drawings can also be obtained based on these drawings without any creative effort.

1 is a transmission electron microscope photograph of the gold-silver nanoalloy modified perovskite-like composite material prepared in Example 1.

Figure 2: a is the ultraviolet-visible extinction spectrum of the perovskite-like prepared in Example 1 of the present invention, and b is the ultraviolet-visible extinction spectrum of the perovskite-like/nano-gold-silver alloy composite material prepared in Example 1.

Figure 3 is a graph of the SERS response for formaldehyde analysis.

Fig. 4 is the standard curve diagram of peak value and response concentration at 840cm ^-1 for each concentration of formaldehyde in Example 1.

FIG. 5 is the SERS spectrum of the actual sample test of the water samples of Example 1 and Example 2 of the present invention.

6 is a graph showing the SERS response of the solid-state surface-enhanced Raman scattering substrate prepared in Example 1 of the present invention to a series of formaldehyde structural analogs.

7 is a graph showing the SERS response of the solid-state surface-enhanced Raman scattering substrate prepared in Example 1 of the present invention to the coexistence of a series of formaldehyde structural analogs and formaldehyde.

Fig. 8a is the response diagram of 11 consecutive SERS tests of the present invention, Fig. 8b is the response diagram of the random 11-point SERS test, Fig. 8c is the SERS test response diagram of 11 batches of solid-state surface-enhanced Raman scattering substrates, and Fig. 8d is the 11-day solid-state surface-enhanced Raman scattering test response diagram. Mann scattering substrate SERS test response plot.

Detailed ways

In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention clearer, the present invention will be further described in detail below with reference to the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, but not to limit the present invention.

Example 1

A quantitative analysis method for formaldehyde in a water environment, comprising the following steps:

1) Preparation of solid-state surface-enhanced Raman scattering substrates;

Add 2mmol of lead nitrate and 2mmol of bismuth nitrate to a 50mL round-bottomed flask, then add 40mL of ethylene glycol and 2mmol of ionic liquid 1-hexadecyl-3-methylimidazolium bromide and stir for 30min, then transfer to 50mL of polytetrafluoroethylene Ethylene reactor, react at 140 ° C for 24 h. Finally, the perovskite-like nanomaterials with a diameter of about 800 nm were obtained by washing with absolute ethanol and ultrapure water for three times respectively and drying.

Disperse 100 mg of perovskite into 72 mL of ultrapure water, ultrasonically disperse for 30 min, then heat to boiling, add 4 mL of 15 mmol L ^-1 chloroauric acid and silver nitrate at the same time, continue heating for 10 min, and then add 8 mL of 60 mmol L ^-1 The sodium citrate solution was kept in a boiling state for 20 min, then cooled to room temperature, washed with ultrapure water for 3 times, and dried to obtain a gold-silver nanoalloy modified perovskite-like composite material. The perovskite-like composites decorated with gold-silver nano-alloys were examined by transmission electron microscopy. From Figure 1, it can be seen that the gold-silver nano-alloys are uniformly modified on the perovskite-like surface, which can ensure a better SERS enhancement effect. In addition, the perovskite-like and gold-silver nanoalloy-modified perovskite-like composites were characterized by UV-extinction spectroscopy, as shown in Fig. The ore composite showed a significant absorption peak at 492 nm, indicating the successful synthesis of perovskite-like modified gold-silver nanoalloys.

Prepare 1.5 mg·mL ^-1 of gold-silver nanoalloy-modified perovskite-like composite material, take 4 mL of the above solution with a syringe, and load the gold-silver nanoalloy-modified perovskite-like composite material in a diameter of 13 mm by filtration. The solid surface-enhanced Raman scattering substrate is obtained on the qualitative filter paper.

2) Drawing of formaldehyde standard curve:

Formaldehyde standard solutions with concentrations of 20μg·L ^-1 , 50μg·L ^-1 , 100μg·L ^-1 , 200μg·L ^-1 , 400μg·L ^-1 , and 500μg·L ^-1 were prepared respectively. In addition, the formaldehyde derivatization step is: add 0.2 mL of 10 mg·L ^-1 4-amino-5-hydrazino-3-mercapto-1,2,4-triazole and 0.2 mL of 1 mol·L to 0.5 mL of standard formaldehyde solution ^-1 NaOH, then incubated for 20min. Aspirate 5-10μL of the derivatized solution, and use the Delta Nu Raman instrument for direct detection. The excitation intensity is 48mV and the integration time is 5s. The solution of each concentration is continuously detected 3 times, the average value and relative deviation are taken, and 840cm ^-1 is drawn. The peak at Raman shift-formaldehyde concentration standard curve is shown in Figures 3 and 4. The detection limit is the lowest concentration that can detect three times the signal-to-noise ratio signal, and the detection limit is 2.6μg·L ^-1 (S/N=3). The linear range and detection limit of this method can meet the requirements of actual sample analysis. need.

3) Detection of formaldehyde in water samples:

Take 10mL of lake water, first settle it naturally for 24h, then centrifuge at 5000 rpm for 5min, and finally filter it with a 0.22μm nylon membrane, and finally take 0.5mL and 0.2mL of 10mg·L ^-1 4-amino-5- Hydrazino-3-mercapto-1,2,4-triazole and 0.2 mL of 1 mol·L ^-1 sodium hydroxide were incubated for 20 min, and finally SERS detection was performed. The measured SERS signal is shown in Figure 5. The test was performed three times in a row, and the average value and relative standard deviation of the peak at 840cm ^-1 of the three data were calculated and substituted into the standard curve, indicating that the concentration of formaldehyde in the lake water sample was 207.6 μg·L ^-1 .

Then, the samples were spiked with standard solutions of 20μg·L ^-1 , 50μg·L ^-1 and 200μg·L ^-1 of formaldehyde standard solution added to the migration solution, and then SERS detection was carried out. Calculate the peak mean value and relative deviation at 840cm ^-1 of the three data, and substitute them into the standard curve to obtain the formaldehyde concentration in the spiked sample.

The detection accuracy of the established SERS analytical method was verified by high performance liquid chromatography (HPLC). Take 5mL of pre-treated lake water, add 5mL of 3mg·mL ^-1 2,4-dinitrophenylhydrazine solution, and incubate at 60°C for 1h. Then pass through a 0.22 μm microporous membrane, and the filtrate is used for HPLC determination. The high-performance liquid chromatograph was equipped with a diode array detector (Shimadzu Corporation, Japan), whose detection wavelength was 360 nm, and the selected chromatographic column was a Diamonsil C18 column (250 mm×4.6 mm, 5 μm). The mobile phase is 0.1% trifluoroacetic acid (A)-acetonitrile (B), and gradient elution is adopted. The elution conditions are: 0-5min: mobile phase B increases from 30% to 70%; 5-10min: mobile phase B is from 70% to 80%; 10-12min: mobile phase B decreased from 80% to 30%; 12-17min: mobile phase B was maintained at 30%; flow rate was 1.0mL/min, injection volume was 20μL. The HPLC detection showed that the formaldehyde concentration in the lake water sample was 209.1(±0.4)μg·L ^-1 , and the relative deviation from the SERS analysis method was 4.9%, which proved the reliability of the quantitative analysis method of the present invention.

In order to verify that the solid surface-enhanced Raman scattering substrate has specific selection and anti-interference for formaldehyde, the method of the present invention is used to detect substances with similar structure of formaldehyde: acetone, methanol, ethanol, acetonitrile, acetaldehyde, acetic acid, ethyl acetate , and its SERS spectrum is shown in Figure 6. It can be seen from FIG. 6 that the SERS responses of acetone, methanol, ethanol, acetonitrile, acetaldehyde, acetic acid, and ethyl acetate are all weak in the detection of the above-mentioned eight substances using the solid surface-enhanced Raman scattering substrate of the present invention. In addition, Figure 7 is the SERS response diagram of the above-mentioned series of formaldehyde structural analogs coexisting with formaldehyde. It can be seen from Figure 7 that when formaldehyde and the above-mentioned interfering substances coexist, the SERS response hardly changes. It can be seen that the method of the present invention can accurately Determination of formaldehyde content.

In order to verify that the solid-state surface-enhanced Raman scattering substrate has good repeatability and reproducibility for formaldehyde detection, 11 consecutive SERS tests, random 11-point SERS tests, and 11 batches of solid-state surface-enhanced Raman scattering substrates were performed on the solid-state surface-enhanced Raman scattering substrate. The results of the Raman scattering substrate SERS test and the solid-state surface-enhanced Raman scattering substrate SERS test for 11 consecutive days are shown in Figures 8a-8d. It can be seen from FIG. 8 that the solid surface-enhanced Raman scattering substrate of the present invention has good repeatability and reproducibility for formaldehyde detection, and can be used for the test of formaldehyde content in water environment.

Example 2

A quantitative analysis method for formaldehyde in a water environment, comprising the following steps:

1) Preparation of solid-state surface-enhanced Raman scattering substrates;

1.5mmol of lead nitrate and 1.5mmol of bismuth nitrate were respectively added to the 50mL round-bottomed flask, then 30mL of ethylene glycol and 1.5mmol of ionic liquid 1-hexadecyl-3-methylimidazolium bromide were added and stirred for 40min, and then randomly transferred to 50mL Teflon reaction kettle, react at 150°C for 22h. Finally, the perovskite-like nanomaterials with a diameter of about 800 nm were obtained by washing with absolute ethanol and ultrapure water for three times respectively and drying.

Disperse 80 mg of perovskite into 58 mL of ultrapure water, ultrasonically disperse for 40 min, then heat to boiling, add 2 mL of 15 mmol L ^-1 chloroauric acid and silver nitrate at the same time, continue heating for 15 min, and then add 8 mL of 30 mmol L ^-1 The sodium citrate solution was kept in a boiling state for 25 min, randomly cooled to room temperature, washed with ultrapure water for 3 times, and then dried to obtain a gold-silver nanoalloy modified perovskite-like composite material. Perovskite-like composites decorated with gold-silver nanoalloys by transmission electron microscopy.

Prepare 2 mg·mL ^-1 of gold-silver nanoalloy-modified perovskite-like composites, take 3 mL of the above solution with a syringe, and load the gold-silver nanoalloy-modified perovskite-like composites on 13 mm qualitative filter paper by filtration That is, a solid surface-enhanced Raman scattering substrate is obtained.

2) Drawing of formaldehyde standard curve:

Formaldehyde standard solutions with concentrations of 20μg·L ^-1 , 50μg·L ^-1 , 100μg·L ^-1 , 200μg·L ^-1 , 400μg·L ^-1 , and 500μg·L ^-1 were prepared respectively. In addition, the formaldehyde derivatization step is: add 0.2 mL of 10 mg·L ^-1 4-amino-5-hydrazino-3-mercapto-1,2,4-triazole and 0.2 mL of 1 mol·L to 0.5 mL of standard formaldehyde solution ^-1 NaOH, then incubated for 20min. Aspirate 5-10μL of the derivatized solution, and use the Delta Nu Raman instrument for direct detection. The excitation intensity is 48mV and the integration time is 5s. The solution of each concentration is continuously detected 3 times, the average value and relative deviation are taken, and 840cm ^-1 is drawn. The peak value at Raman shift-formaldehyde concentration standard curve, the detection limit is the lowest concentration that can detect three times the signal-to-noise ratio signal, the detection limit is 2.6μg·L ^-1 (S/N=3), this method is linear The range and detection limit can meet the needs of actual sample analysis.

3) Detection of formaldehyde in water samples:

Take 10mL of reservoir water, first settle naturally for 24h, then centrifuge at 6000 rpm for 7min, and finally filter it with a 0.22μm nylon membrane, and finally take 0.5mL and 0.2mL of 10mg·L ^-1 4-amino-5 - Hydrazino-3-mercapto-1,2,4-triazole and 0.2mL 1mol·L ^-1 sodium hydroxide were incubated for 20min, and finally SERS detection was performed. The measured SERS signal is shown in Figure 5, and the test was performed three times in a row, and the average value and relative standard deviation of the peak at 840cm ^-1 of the three data were calculated and substituted into the standard curve, indicating that the formaldehyde concentration in the lake water sample was 181.9μg·L ^-1 .

Then, the samples were spiked with standard solutions of 20μg·L ^-1 , 50μg·L ^-1 and 200μg·L ^-1 of formaldehyde standard solution added to the migration solution, and then SERS detection was carried out. Calculate the peak mean value and relative deviation at 840cm ^-1 of the three data, and substitute them into the standard curve to obtain the formaldehyde concentration in the spiked sample.

The detection accuracy of the established SERS analytical method was verified by high performance liquid chromatography (HPLC). Take 5mL of pre-treated reservoir water, add 5mL of 3mg·mL ^-1 2,4-dinitrophenylhydrazine solution, and incubate at 60°C for 1h. Then pass through a 0.22 μm microporous membrane, and the filtrate is used for HPLC determination. The high-performance liquid chromatograph was equipped with a diode array detector (Shimadzu Corporation, Japan), whose detection wavelength was 360 nm, and the selected chromatographic column was a Diamonsil C18 column (250 mm×4.6 mm, 5 μm). The mobile phase is 0.1% trifluoroacetic acid (A)-acetonitrile (B), and gradient elution is adopted. The elution conditions are: 0-5min: mobile phase B increases from 30% to 70%; 5-10min: mobile phase B changes from 70% to 80%; 10-12min: mobile phase B decreased from 80% to 30%; 12-17min: mobile phase B was maintained at 30%; flow rate was 1.0mL/min, injection volume was 20μL. The formaldehyde concentration in the lake water sample was 186.4(±1.7)μg·L ^-1 by HPLC detection, and the relative deviation from the SERS analysis method was 6.9%, which proved the reliability of the analysis method.

Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Anyone who is familiar with this technology can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, The protection scope of the present invention should be defined by the claims.

Claims (10)

1. A method of making a solid state surface enhanced raman scattering substrate, the method comprising:

(1) preparing a perovskite-like nano material: mixing a lead nitrate solution and a bismuth nitrate solution, adding ethylene glycol and ionic liquid 1-hexadecyl-3-methylimidazolium bromide, uniformly mixing, reacting at the temperature of 120-160 ℃ for 18-30h, washing, and drying to obtain the perovskite-like nano material;

(2) preparing a gold-silver nano alloy modified perovskite-like composite material: dispersing the perovskite-like nano material prepared in the step (1) into water, performing ultrasonic dispersion, heating to boil, adding chloroauric acid and silver nitrate solution, continuing heating for 5-20min, adding sodium citrate solution, keeping the boiling state for 15-30min, cooling, washing and drying to obtain the gold-silver nano alloy modified perovskite-like composite material;

(3) preparing a solid surface enhanced Raman scattering substrate: preparing the gold-silver nano alloy modified perovskite-like composite material prepared in the step (2) into the perovskite-like composite material with the concentration of 1.0-3.0mg mL ^-1 The dispersion liquid is filtered on the surface of qualitative filter paper, and then the solid surface enhanced Raman scattering substrate can be obtained.

2. The preparation method according to claim 1, wherein in the step (1), the molar ratio of the lead nitrate to the bismuth nitrate is 1-2: 1 to 2.

3. The method according to claim 1, wherein in the step (1), the molar ratio of the lead nitrate to the 1-hexadecyl-3-methylimidazolium bromide is: 1-2: 1 to 2.

4. The preparation method according to claim 1, wherein in the step (2), the mass ratio of the chloroauric acid to the silver nitrate is 1-2: 1, the mass ratio of silver nitrate to the perovskite-like nano material is 1: 8-16.

5. The preparation method according to claim 4, wherein in the step (2), the mass ratio of the sodium citrate to the perovskite-like nanomaterial is 1.24:1 to 1.24: 2.

6. The solid surface-enhanced Raman scattering substrate prepared by the preparation method according to any one of claims 1 to 5.

7. A quantitative detection method for formaldehyde in a water environment is characterized by comprising the following steps:

step S01: preparing formaldehyde standard solutions with different concentrations, detecting by using the solid surface enhanced Raman scattering substrate of claim 6, and drawing a standard curve according to the peak value of the characteristic Raman shift position of the obtained formaldehyde with different concentrations and the concentration of the formaldehyde standard solution;

step S02: the solid-state surface-enhanced Raman scattering substrate of claim 6 is adopted to detect a pretreated water sample, and the peak value of the obtained characteristic Raman shift position is compared with the standard curve to obtain the concentration of formaldehyde in the water sample.

8. The quantitative determination method of claim 7, wherein the pretreatment of the water sample comprises natural sedimentation, centrifugation, and membrane filtration.

9. The quantitative determination method according to claim 8, wherein the standard formaldehyde solution or water sample is subjected to derivatization before the detection on the solid-state surface enhanced Raman scattering substrate, and specifically comprises: adding a 4-amino-5-hydrazino-3-mercapto-1, 2, 4-triazole solution and a sodium hydroxide solution into a formaldehyde-containing solution, and then incubating for 10-60 min.

10. The application of the quantitative detection method according to any one of claims 7 to 9 in the environmental field.

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