A method for detecting hydrogen sulfide

Abstract

The present invention relates to the field of detection technology, and in particular to a method for detecting hydrogen sulfide. The method for detecting hydrogen sulfide of the present invention comprises the following steps: hydrogen sulfide gas reacts under the catalysis of a sensitive material, and a luminescent signal of the gas after the reaction is detected; the sensitive material comprises at least one of Fe3O4, α-Fe2O3 and γ-Fe2O3; the preparation of Fe3O4 comprises: FeCl3·6H2O aqueous solution, FeCl2·4H2O aqueous solution and ammonia solution react for 25 to 35 minutes, and then are separated, washed and dried in sequence; the preparation of α-Fe2O3 comprises: Fe3O4 is calcined at 300±5°C for 2.8 to 3.2 hours; the preparation of γ-Fe2O3 comprises: Fe3O4 is calcined at 500±5°C for 2.8 to 3.2 hours. The method for detecting hydrogen sulfide of the present invention has high sensitivity, good specificity, fast speed, good reproducibility, good stability and high accuracy.

Description

Technical Field

[0001] The present invention relates to the field of detection technology, and in particular to a method for detecting hydrogen sulfide. Background Art

[0002] Hydrogen sulfide (H2S) is a colorless, acidic, highly toxic gas with a foul odor resembling rotten eggs. It is widely present in industrial feedstock gases such as natural gas, coke oven gas, and liquefied petroleum gas. Hydrogen sulfide is both a nerve agent and an asphyxiating and irritating gas, primarily damaging the central nervous system, respiratory system, eyes, and heart. Mild poisoning symptoms include tearing, stinging eyes, runny nose, and a burning sensation in the throat, often accompanied by headaches, dizziness, fatigue, and nausea. Moderate poisoning worsens mucosal irritation, with symptoms such as coughing, chest tightness, blurred vision, conjunctival edema, and significant headaches and dizziness, along with mild impairment of consciousness. Severe poisoning can result in coma, pulmonary edema, and respiratory and circulatory failure. Even low-concentration H2S gas leaks can pose significant risks to the environment and human health. Therefore, convenient and selective detection of H2S gas is crucial for environmental hygiene and public safety.

[0003] In view of this, this invention is proposed. Summary of the Invention

[0004] The object of the present invention is to provide a method for detecting hydrogen sulfide with high sensitivity, good specificity, fast speed, good reproducibility, good stability and high accuracy.

[0005] In order to achieve the above-mentioned purpose of the present invention, the following technical solutions are adopted:

[0006] The present invention provides a method for detecting hydrogen sulfide, comprising the following steps:

[0007] The hydrogen sulfide gas reacts under the catalysis of the sensitive material, and the luminescent signal of the gas after the reaction is detected; the sensitive material includes at least one of Fe3O4, α-Fe2O3 and γ-Fe2O3;

[0008] The preparation method of Fe3O4 comprises: reacting FeCl3·6H2O aqueous solution, FeCl2·4H2O aqueous solution and ammonia aqueous solution for 25 to 35 minutes, and then separating, washing and drying in sequence to obtain Fe3O4;

[0009] The preparation method of α-Fe2O3 comprises: calcining the Fe3O4 at 300±5°C for 2.8 to 3.2 hours to obtain the α-Fe2O3;

[0010] The preparation method of the γ-Fe2O3 comprises: calcining the Fe3O4 at 500±5°C for 2.8 to 3.2 hours to obtain the γ-Fe2O3.

[0011] Furthermore, the molar ratio of FeCl3·6H2O in the FeCl3·6H2O aqueous solution to FeCl2·4H2O in the FeCl2·4H2O aqueous solution is 1:(0.45-0.55).

[0012] Furthermore, the mass ratio of FeCl3·6H2O in the FeCl3·6H2O aqueous solution to NH3 in the ammonia aqueous solution is 10:(0.2-1).

[0013] Furthermore, the concentration of the FeCl3·6H2O aqueous solution is 0.08 to 0.12 mol / L.

[0014] Furthermore, the concentration of the FeCl2·4H2O aqueous solution is 0.045 to 0.055 mol / L.

[0015] Furthermore, the concentration of the ammonia solution is 4wt% to 6wt%.

[0016] Further, it includes at least one of the following features (1) to (3);

[0017] (1) The separation includes magnetic decantation separation;

[0018] (2) The washing comprises: washing with ethanol and deionized water;

[0019] (3) The drying comprises: drying at 55-65°C for 10-15 hours.

[0020] Furthermore, the detection wavelength of the luminescent signal is 300 to 555 nm.

[0021] Furthermore, the reaction temperature is 180-300°C.

[0022] Furthermore, the carrier gas includes air, and the flow rate of the carrier is 500 to 950 mL / min.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The present invention adopts Fe3O4, α-Fe2O3 and γ-Fe2O3 prepared by a specific preparation method as sensitive materials, and uses catalytic luminescence to detect hydrogen sulfide, which has the advantages of high sensitivity, good specificity, fast speed, good reproducibility, good stability and accuracy, and can specifically measure hydrogen sulfide without interference from other substances. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0026] Figure 1 These are the XRD spectra of Fe3O4 prepared in Example 1, γ-Fe2O3 prepared in Example 2, and α-Fe2O3 prepared in Example 3 of the present invention.

[0027] Figure 2 TEM images of γ-Fe2O3 prepared in Example 2 of the present invention, α-Fe2O3 prepared in Example 3, and Fe3O4 prepared in Example 1.

[0028] Figure 3 This is the response signal of hydrogen sulfide on the surface of different materials in the present invention.

[0029] Figure 4 These are the response signals of different gases on the surface of γ-Fe2O3 prepared in Example 2, α-Fe2O3 prepared in Example 3, and Fe3O4 prepared in Example 1 of the present invention.

[0030] Figure 5 It is the response intensity of hydrogen sulfide, carbon disulfide, isobutyraldehyde and ammonium sulfide on the surface of commercial γ-Fe2O3 of the present invention.

[0031] Figure 6 Response curves of γ-Fe2O3 prepared in Example 2 of the present invention to different concentrations of hydrogen sulfide.

[0032] Figure 7 Response curves of α-Fe2O3 prepared in Example 3 of the present invention to different concentrations of hydrogen sulfide.

[0033] Figure 8 This is the response curve of Fe3O4 prepared in Example 1 of the present invention to different concentrations of hydrogen sulfide.

[0034] Figure 9 The reproducibility of hydrogen sulfide detection using the γ-Fe2O3 prepared in Example 2 of the present invention.

[0035] Figure 10 The reproducibility of hydrogen sulfide detection using the α-Fe2O3 prepared in Example 3 of the present invention.

[0036] Figure 11 The reproducibility of detecting hydrogen sulfide using Fe3O4 prepared in Example 1 of the present invention.

[0037] Figure 12The stability of hydrogen sulfide was tested for the γ-Fe2O3 prepared in Example 2 of the present invention, the α-Fe2O3 prepared in Example 3, and the Fe3O4 prepared in Example 1.

[0038] Figure 13 This is a relationship diagram between the detection signal of hydrogen sulfide detected by γ-Fe2O3 prepared in Example 2 of the present invention and the hydrogen sulfide concentration.

[0039] Figure 14 This is a relationship diagram between the detection signal of hydrogen sulfide detected by α-Fe2O3 prepared in Example 3 of the present invention and the hydrogen sulfide concentration.

[0040] Figure 15 This is a relationship diagram between the detection signal of hydrogen sulfide detected by Fe3O4 prepared in Example 1 of the present invention and the hydrogen sulfide concentration. DETAILED DESCRIPTION

[0041] The technical scheme of the present invention will be clearly and completely described below in conjunction with the accompanying drawings and specific embodiments, but it will be understood by those skilled in the art that the following described embodiments are part of embodiments of the present invention, rather than all embodiments, and are only used to illustrate the present invention, and should not be considered as limiting the scope of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work are within the scope of protection of the present invention. Those who do not specify specific conditions in the embodiments are carried out according to normal conditions or the conditions recommended by the manufacturer. Those whose reagents or instruments are not specified by the manufacturer are conventional products that can be purchased commercially.

[0042] The following is a detailed description of a method for detecting hydrogen sulfide according to the present invention.

[0043] In some embodiments of the present invention, a method for detecting hydrogen sulfide is provided, comprising the following steps:

[0044] The hydrogen sulfide gas reacts under the catalysis of the sensitive material, and the luminescent signal of the gas after the reaction is detected; the sensitive material includes at least one of Fe3O4, α-Fe2O3 and γ-Fe2O3;

[0045] The preparation method of Fe3O4 comprises: reacting an aqueous solution of FeCl3·6H2O, an aqueous solution of FeCl2·4H2O and an aqueous ammonia solution for 25 to 35 minutes, and then separating, washing and drying in sequence to obtain Fe3O4;

[0046] The preparation method of α-Fe2O3 comprises: calcining the above-mentioned Fe3O4 at 300±5°C for 2.8 to 3.2 hours to obtain α-Fe2O3;

[0047] The preparation method of γ-Fe2O3 comprises: calcining the above-mentioned Fe3O4 at 500±5°C for 2.8-3.2h to obtain γ-Fe2O3.

[0048] The catalyst preparation method has a significant impact on the catalyst's microstructure, including its crystal form, particle size, specific surface area, and exposed crystal faces. Therefore, even for the same catalyst, differences in preparation methods can have a significant impact on its performance.

[0049] The present invention uses Fe3O4, α-Fe2O3 and γ-Fe2O3 prepared by a specific preparation method as sensitive materials for catalytic luminescence detection of hydrogen sulfide, which has the advantages of high sensitivity, good specificity, fast speed, good reproducibility, good stability and accuracy. It can specifically measure hydrogen sulfide without interference from other substances. Existing commercial Fe3O4, α-Fe2O3 and γ-Fe2O3 also respond to other gases in addition to hydrogen sulfide, and have poor specificity.

[0050] In some embodiments of the present invention, the temperature for the reaction of the FeCl3·6H2O aqueous solution, the FeCl2·4H2O aqueous solution and the ammonia aqueous solution is room temperature; preferably 15 to 30°C.

[0051] In some embodiments of the present invention, the molar ratio of FeCl3·6H2O in the FeCl3·6H2O aqueous solution to FeCl2·4H2O in the FeCl2·4H2O aqueous solution is 1:(0.45-0.55).

[0052] In some embodiments of the present invention, the mass ratio of FeCl3·6H2O in the FeCl3·6H2O aqueous solution to NH3 in the ammonia aqueous solution is 10:(0.2-1).

[0053] In some embodiments of the present invention, the volume ratio of the FeCl 3 · 6H 2 O aqueous solution to the ammonia aqueous solution is 100: (1-5).

[0054] In some embodiments of the present invention, the concentration of the FeCl3·6H2O aqueous solution is 0.08 to 0.12 mol / L.

[0055] In some embodiments of the present invention, the concentration of the FeCl2·4H2O aqueous solution is 0.045 to 0.055 mol / L.

[0056] In some embodiments of the present invention, the concentration of the ammonia solution is 4 wt % to 6 wt %.

[0057] In some embodiments of the invention, separating comprises separation by magnetic decantation.

[0058] In some embodiments of the present invention, washing comprises: washing with ethanol and deionized water;

[0059] In some embodiments of the present invention, drying comprises: drying at 55-65° C. for 10-15 hours.

[0060] In some specific embodiments of the present invention, the preparation method of Fe3O4 comprises the following steps:

[0061] FeCl3·6H2O aqueous solution and FeCl2·4H2O aqueous solution were mixed, and then ammonia aqueous solution was slowly added dropwise under mechanical stirring. After reacting at room temperature for 30 minutes, the crude product was separated by magnetic decantation.

[0062] The crude product was washed with anhydrous ethanol and deoxygenated deionized water for several times, and then dried in a vacuum drying oven at 60° C. for 12 h to obtain Fe 3 O 4 .

[0063] In some specific embodiments of the present invention, the preparation method of α-Fe2O3 comprises the following steps:

[0064] The Fe3O4 prepared by the above-mentioned Fe3O4 preparation method was calcined at 300°C for 3h to obtain α-Fe2O3.

[0065] In some specific embodiments of the present invention, the preparation method of γ-Fe2O3 comprises the following steps:

[0066] The Fe3O4 prepared by the above-mentioned Fe3O4 preparation method was calcined at 500°C for 3h to obtain γ-Fe2O3.

[0067] In some embodiments of the present invention, the detection wavelength of the luminescent signal is 300-555 nm; typically but not limitatively, for example, the detection wavelength of the luminescent signal can be 300 nm, 320 nm, 350 nm, 380 nm, 410 nm, 450 nm, 500 nm, 555 nm or a range value consisting of any two of them; preferably, the detection wavelength of the luminescent signal is 350 nm.

[0068] In some embodiments of the present invention, the reaction temperature is 180-300°C; typically but not limiting, for example, the reaction temperature can be 180°C, 200°C, 220°C, 240°C, 260°C, 280°C, 300°C or a range consisting of any two thereof; preferably, the reaction temperature is 210°C.

[0069] In some embodiments of the present invention, the carrier gas includes air, and the flow rate of the carrier is 500-950 mL / min; typically but not limitatively, for example, the flow rate of the carrier can be 500 mL / min, 600 mL / min, 700 mL / min, 800 mL / min, 900 mL / min, 950 mL / min or a range consisting of any two thereof; preferably, the flow rate of the carrier is 900 mL / min.

[0070] In some embodiments of the present invention, the method for detecting hydrogen sulfide specifically comprises the following steps:

[0071] Hydrogen sulfide gas enters the detection device and is heated to the reaction temperature. The hydrogen sulfide gas contacts the sensitive material. On the surface of the sensitive material, the hydrogen sulfide gas is oxidized by oxygen in the air to generate a catalytic luminescence signal, and the generated luminescence signal is detected.

[0072] In some embodiments of the present invention, the detection device includes: an automatic sampling unit, a catalytic luminescence reactor, and a detection instrument;

[0073] Among them, the automatic sampling unit can pass high-concentration hydrogen sulfide gas into the gas mixer, use air as the diluent gas to dilute it to the target concentration of hydrogen sulfide gas, and then inject it through the six-way valve to complete fully automatic cyclic quantitative timing injection;

[0074] The catalytic luminescence reactor includes a reaction chamber, which includes an air inlet, an air outlet, and a base. The reaction chamber includes a quartz tube, and the base includes a ceramic rod. A catalytic layer is attached to the surface of the ceramic rod. The material of the catalytic layer includes the above-mentioned sensitive material, and the thickness of the catalytic layer is 2 to 5 mm. The hydrogen sulfide gas flow enters the air inlet of the reaction chamber, reacts with the catalytic layer, and then flows out of the air outlet of the reaction chamber.

[0075] The detection instrument includes a weak luminescence measuring instrument host (BPCL-1-TGC), a detector and a controller, which can accurately detect the light signal generated by hydrogen sulfide during catalytic luminescence.

[0076] Example 1

[0077] The preparation method of Fe3O4 provided in this embodiment comprises the following steps:

[0078] Dissolve 2.703 g of FeCl3·6H2O in 100 mL of deionized water to obtain a FeCl3·6H2O aqueous solution; dissolve 0.9942 g of FeCl2·4H2O in 100 mL of deionized water to obtain a FeCl2·4H2O aqueous solution;

[0079] The FeCl3·6H2O aqueous solution and the FeCl2·4H2O aqueous solution were transferred to a three-necked flask. 1 to 5 mL of a 5 wt% ammonia aqueous solution was slowly added dropwise under mechanical stirring at room temperature. Stirring was continued for 30 minutes. The crude product was separated by magnetic decantation to obtain a crude product. The crude product was washed multiple times with anhydrous ethanol and deoxygenated deionized water, and then dried in a vacuum drying oven at 60°C for 12 hours to obtain Fe3O4.

[0080] Example 2

[0081] The preparation method of γ-Fe2O3 provided in this embodiment comprises the following steps:

[0082] The Fe3O4 prepared in Example 1 was placed in a muffle furnace and calcined at 300°C for 3 hours to obtain γ-Fe2O3.

[0083] Example 3

[0084] The preparation method of γ-Fe2O3 provided in this embodiment comprises the following steps:

[0085] The Fe3O4 prepared in Example 1 was placed in a muffle furnace and calcined for 3 h at 500°C to obtain α-Fe2O3.

[0086] Test Example 1

[0087] XRD tests were performed on Fe3O4 obtained in Example 1, γ-Fe2O3 obtained in Example 2, and α-Fe2O3 obtained in Example 3. The results are as follows: Figure 1 shown.

[0088] from Figure 1 It can be seen that the Fe3O4 prepared in Example 1 is a cubic phase with a PDF standard card number of 88-0315; the γ-Fe2O3 prepared in Example 2 is a cubic phase with a PDF standard card number of 39-1346; and the α-Fe2O3 prepared in Example 3 is a hexagonal phase with a PDF standard card number of 33-0664.

[0089] TEM tests were performed on the γ-Fe2O3 obtained in Example 2, the α-Fe2O3 obtained in Example 3, and the Fe3O4 obtained in Example 1. The results are as follows: Figure 2 As shown. Among them, Figure 2 (a) is the γ-Fe2O3 prepared in Example 2, Figure 2 (b) is the α-Fe2O3 prepared in Example 3, Figure 2 (c) is Fe3O4 obtained in Example 1.

[0090] from Figure 2It can be seen that the average particle size of Fe3O4 prepared in Example 1 is 263 nm; the average particle size of γ-Fe2O3 prepared in Example 2 is 15 nm; and the average particle size of α-Fe2O3 prepared in Example 3 is 20 nm.

[0091] Test Example 2

[0092] Detection device: including: automatic sampling unit, catalytic luminescence reactor and detection instrument;

[0093] The automatic sampling unit introduces high-concentration hydrogen sulfide gas into the gas mixer, uses air as the diluent gas to dilute it to the target concentration of hydrogen sulfide gas, and then injects the gas through the six-way valve to complete the fully automatic cyclic quantitative timing injection.

[0094] The catalytic luminescence reactor includes a quartz tube, the quartz tube includes an air inlet, an air outlet and a ceramic rod, the surface of the ceramic rod is attached with a catalytic layer, the material of the catalytic layer includes a sensitive material, and the thickness of the catalytic layer is 2 to 5 mm;

[0095] The detection instrument includes a weak luminescence measuring instrument host (BPCL-1-TGC), a detector and a controller, which can accurately detect the light signal generated by hydrogen sulfide during catalytic luminescence.

[0096] Detection steps: The gas to be tested enters the catalytic luminescence reactor through the automatic sampling unit and is heated to the reaction temperature. The gas to be tested comes into contact with the sensitive material of the catalytic layer. On the surface of the sensitive material, the gas to be tested is oxidized by oxygen in the air to generate a catalytic luminescence signal, which is then detected by a detection instrument.

[0097] Detection conditions: detection wavelength of 350 nm, reaction temperature of 210°C, carrier gas of air, and carrier gas flow rate of 900 mL / min.

[0098] The following tests were all performed using the above-mentioned testing device, testing steps and testing conditions.

[0099] γ-Fe2O3 prepared in Example 2, α-Fe2O3 prepared in Example 3, Fe3O4 prepared in Example 1, ZnO, SiO2, DyO and Y2O3 were used as sensitive materials to detect hydrogen sulfide gas with a concentration of 200ppm. The results are as follows: Figure 3 shown.

[0100] from Figure 3 It can be seen that when γ-Fe2O3 detects hydrogen sulfide, the luminescence signal is the strongest, and the signals of α-Fe2O3, Fe3O4, ZnO, SiO2, DyO and Y2O3 decrease in turn.

[0101] The γ-Fe2O3 prepared in Example 2, the α-Fe2O3 prepared in Example 3, and the Fe3O4 prepared in Example 1 were respectively used to detect hydrogen sulfide gas with a concentration of 200 ppm and the following substances with a concentration of 20,000 ppm: ethanol, n-propanol, n-butanol, acetic acid, 2-heptanone, cycloheptanone, acetophenone, n-propanal, formaldehyde, phenylacetaldehyde, isobutyraldehyde, n-butyraldehyde, methylglyoxal, acetaldehyde, acrolein, benzene, o-xylene, ethylbenzene, isopropylbenzene, trimethylamine, ethanethiol, dimethyl sulfide, styrene, ammonia water, ammonium sulfide solution, petroleum ether, carbon disulfide, trichloroethylene, 1,2-dichloroethane, dimethylamine, diethylamine, cyclopropylcarbinol, and methanol.

[0102] from Figure 4 It can be seen that the γ-Fe2O3 prepared in Example 2, the α-Fe2O3 prepared in Example 3, and the Fe3O4 prepared in Example 1 all respond only to hydrogen sulfide and have no response to other gases, and have excellent specificity.

[0103] Commercialized γ-Fe2O3 purchased from Bohuasi Nanotechnology (Ningbo) Co., Ltd. was used to detect hydrogen sulfide gas with a concentration of 200ppm and other gases with a concentration of 20000ppm. The other gases were carbon disulfide, isobutanol and ammonium sulfide. The results are as follows Figure 5 shown.

[0104] from Figure 5 It can be seen that the response intensity of hydrogen sulfide on the commercial γ-Fe2O3 surface is lower than that on the γ-Fe2O3 surface prepared in Example 2, and the specificity of the commercial γ-Fe2O3 is poor. Carbon disulfide, isobutyraldehyde, and ammonium sulfide all produced responses; thus, it is demonstrated that the material prepared by the preparation method of the present invention has excellent sensitivity and specific response to hydrogen sulfide.

[0105] The γ-Fe2O3 prepared in Example 2, the α-Fe2O3 prepared in Example 3, and the Fe3O4 prepared in Example 1 were used to detect hydrogen sulfide gas with concentrations of 125ppm, 200ppm, and 303ppm, respectively. The response time and recovery time of the kinetic response curve were recorded, and the results were as follows: Figure 6 、 Figure 7 and Figure 8 As shown. Among them, Figure 6 、 Figure 7 and Figure 8 In the figure, 1 represents hydrogen sulfide gas with a concentration of 300 ppm, 2 represents hydrogen sulfide gas with a concentration of 200 ppm, and 3 represents hydrogen sulfide gas with a concentration of 125 ppm.

[0106] from Figures 6 to 8It can be seen that the material prepared in the present invention starts sampling at 20 seconds, reaches the response peak at 22 seconds, and drops to the baseline at 22.5 seconds. Therefore, the response time is 2 seconds and the recovery time is 0.5 seconds. The prepared material has a rapid detection capability.

[0107] The γ-Fe2O3 prepared in Example 2, the α-Fe2O3 prepared in Example 3, and the Fe3O4 prepared in Example 1 were used to detect hydrogen sulfide gas with a concentration of 200 ppm. The detection was repeated ten times, and the automatic sampling was repeated ten times. The parallel determination was performed, and the sampling time and sampling interval were both 20 seconds. The results are shown in FIG. Figure 9 、 Figure 10 and Figure 11 shown.

[0108] from Figures 9 to 11 It can be seen that the mean luminescence intensities are 7060.6, 3970.4 and 1468.1, respectively, and the relative standard deviations are 1.48%, 2.87% and 4.06%, respectively. The obtained signals can remain stable and have excellent repeatability.

[0109] The γ-Fe2O3 prepared in Example 2, the α-Fe2O3 prepared in Example 3 and the Fe3O4 prepared in Example 1 were used to detect hydrogen sulfide gas with a concentration of 200ppm. The luminescence signal of the detection was repeated for 14 days. The results are as follows: Figure 12 shown.

[0110] from Figure 12 It can be seen that the standard deviations of hydrogen sulfide measured repeatedly for 14 days for the three materials are 1.4%, 2.2% and 3.3%, respectively, showing good stability.

[0111] The γ-Fe2O3 prepared in Example 2, the α-Fe2O3 prepared in Example 3, and the Fe3O4 prepared in Example 1 were used to detect hydrogen sulfide gas at concentrations of 25ppm, 50ppm, 66.67ppm, 100ppm, 125ppm, 166.7ppm, 200ppm, 250ppm, 303ppm, 333ppm, 416.6ppm, 500ppm, 625ppm, 714ppm, 833ppm, 909ppm, and 1000ppm, respectively. The measured catalytic luminescence signals were subjected to linear regression to obtain a standard curve, and the results are shown in FIG. Figure 13 、 Figure 14 and Figure 15 shown.

[0112] from Figure 13 It can be seen that the regression equation corresponding to γ-Fe2O3 is: S=0.23C 2 -22.45C-464.94, correlation coefficient R 2 =0.999; from Figure 14It can be seen that the regression equation corresponding to α-Fe2O3 is: S=0.09C 2 -1.04C-141.02, correlation coefficient R 2 =0.998; from Figure 15 It can be seen that the regression equation corresponding to Fe3O4 is S=0.04C 2 +1.79C-185.62, correlation coefficient R 2 =0.997; where S is the luminous intensity and C is the hydrogen sulfide concentration.

[0113] The γ-Fe2O3 prepared in Example 2 was used to detect three gas samples containing hydrogen sulfide, and the results obtained by gas chromatography-mass spectrometry were taken as the true values. The results are shown in Table 1.

[0114] Gas sample 1 is hydrogen sulfide, ethanol, trichloroethylene and dimethyl sulfide; gas sample 2 is hydrogen sulfide, trimethylamine and trichloroethylene; gas sample 3 is hydrogen sulfide and dimethylamine.

[0115] Table 1

[0116]

[0117] The degrees of freedom of the two sets of data for each sample are both 2. Look up the F value table, F 0.05,2,2 =19.00, F of three samples <F 0.05,2,2 , indicating that there was no significant difference in the precision of the determination results between the two methods.

[0118] f=n1+n2-2=4,P=95%,look up the table and get t 0.05,4 =2.776; t <t 0.05,4 There was no significant difference between the results obtained by the two methods.

[0119] V GC-MS represents the value of GC-MS method parallel determination; V CTL Represents the replicate values ​​of the CTL method.

[0120] A GC-MS represents the average value of the results determined by GC-MS method; A CTL The results represent the average value of the CTL method.

[0121] The relative error is less than 2.5%, and the t test shows that, according to the table, t 0.05,4 =2.776, the test results of three samples t <t 0.05,4 , indicating that there is no significant difference between the results of the two methods.

[0122] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for detecting hydrogen sulfide, characterized in that: The steps include: The hydrogen sulfide gas reacts under the catalysis of the sensitive material, and the luminescent signal of the gas after the reaction is detected; the sensitive material includes at least one of Fe3O4, α-Fe2O3 and γ-Fe2O3; The preparation method of Fe3O4 comprises: reacting an aqueous solution of FeCl3·6H2O, an aqueous solution of FeCl2·4H2O and an aqueous ammonia solution for 25 to 35 minutes, and then separating, washing and drying in sequence to obtain the Fe3O4; The preparation method of α-Fe2O3 comprises: calcining the Fe3O4 at 300±5°C for 2.8-3.2h to obtain the α-Fe2O3; The preparation method of γ-Fe2O3 comprises: calcining the Fe3O4 at 500±5°C for 2.8-3.2h to obtain the γ-Fe2O3; The molar ratio of FeCl3·6H2O in the FeCl3·6H2O aqueous solution to FeCl2·4H2O in the FeCl2·4H2O aqueous solution is 1:(0.45-0.55); The mass ratio of FeCl3·6H2O in the FeCl3·6H2O aqueous solution to NH3 in the ammonia aqueous solution is 10:(0.2~1); The concentration of the FeCl3·6H2O aqueous solution is 0.08~0.12mol / L; The concentration of the FeCl2·4H2O aqueous solution is 0.045~0.055mol / L; The concentration of the ammonia solution is 4wt%~6wt%; The reaction temperature is 180-300°C.

2. The method for detecting hydrogen sulfide according to claim 1, wherein: including at least one of the following features (1) to (3); (1) The separation includes magnetic decantation separation; (2) The washing comprises: washing with ethanol and deionized water; (3) The drying comprises drying at 55-65°C for 10-15 hours.

3. The method for detecting hydrogen sulfide according to claim 1, wherein: The detection wavelength of the luminescent signal is 300~555nm.

4. The method for detecting hydrogen sulfide according to claim 1, wherein: The carrier gas includes air, and the flow rate of the carrier gas is 500-950 mL / min.

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