Analysis method for rapidly determining volatile phenols in drinking natural water

Abstract

The invention relates to the field of volatile phenol detection, and discloses an analysis method for rapidly determining volatile phenol in drinking natural water, which comprises the following steps: balancing a volatile phenol standard solution in water to room temperature, accurately absorbing the volatile phenol standard solution in water, using ultrapure water for volume metering, and uniformly mixing to obtain a volatile phenol standard working reserve intermediate solution in water; using ultrapure water to fix the volume, and uniformly mixing to obtain a standard working stock solution of volatile phenol in water; obtaining water volatile phenol standard working solutions with different concentrations; after instrument conditions are balanced and stably adjusted through a water quality measuring instrument, the to-be-detected sample solution is detected, and the mass concentration of volatile phenol in the to-be-detected sample solution is obtained; the problems that in the prior art, volatile phenol detection is not carried out according to the characteristics of plateau water resources, a sample needs to be pretreated, the number of adopted reagents is large, the reagent amount is large, the reagent toxicity is large, the environmental pollution risk is high, the detection period is long, and the cost is high are solved.

Description

Technical Field

[0001] The invention relates to the field of volatile phenol detection, and in particular to an analytical method for rapidly determining volatile phenol in drinking natural water. Background Art

[0002] Tibet is the region with the richest water resources in my country. The natural water resources in Tibet have a moderate overall water age, are rich in lithium, strontium, metasilicic acid and other natural macro- and trace elements, are naturally weakly alkaline and pollution-free, and are recognized as one of the best freshwater resources in the world.

[0003] Volatile phenols are highly toxic substances that are highly corrosive to the skin and mucous membranes. They can also be absorbed through the skin and mucous membranes to cause poisoning, which is very harmful to the human body. In water bodies, the content of volatile phenols has a significant impact on water quality. When the content of volatile phenols in water is 0.1-0.2 mg / L, fish will have an odor; if it exceeds 5 mg / L, fish will die from poisoning. Therefore, if wastewater containing high concentrations of phenols is used for farmland irrigation, it may cause crops to die or yields to decrease, posing a threat to agricultural production. The strong solubility of volatile phenols means that they can be easily dissolved in water or other solvents, which makes them an important research object in the fields of industrial wastewater treatment and environmental monitoring. In addition, the high solubility of volatile phenols also means that they have strong migration and diffusion capabilities in the environment, thus posing a potential threat to the environment and human health. With the development of national modernization, volatile phenolic substances are widely used in the manufacture of phenolic resins, epoxy resins, nylon fibers, plasticizers, developers, preservatives, pesticides, fungicides, dyes, medicines, spices and explosives, etc. They will inevitably be brought into the water ecological circulation system. Therefore, it is an important monitoring indicator in water quality safety monitoring.

[0004] At present, the research progress of the detection methods of volatile phenols mainly includes 4-aminoantipyrine spectrophotometry, fully automatic flow injection method, gas chromatography-mass spectrometry, etc. These methods have both advantages and disadvantages, but none of them are targeted at the characteristics of water resources in the Tibetan Plateau and the geographical environment of the plateau laboratory. "GB 19298-2014 National Food Safety Standard Packaged Drinking Water", "GB 8537-2018 National Food Safety Standard Drinking Natural Mineral Water", "GB 5749-2022 Drinking Water Hygiene Standard", etc. have set limits on the content of volatile phenols (in terms of phenol) at 2.0ug / L. The detection methods for volatile phenols in "GB5750.4-2023 Standard Test Method for Drinking Water Part 4: Sensory Properties and Physical Indicators" and "GB 8538-2022 National Food Safety Standard Test Method for Drinking Natural Mineral Water" are 4-aminoantipyrine chloroform extraction spectrophotometry, flow injection method, and continuous flow method. These methods require sample pretreatment, use a variety of reagents, large reagent volumes, high reagent toxicity, high risk of environmental pollution, long detection cycle, and high cost. The national standard 4-aminoantipyrine chloroform extraction spectrophotometry and flow injection method have a detection limit of 2.0μg / L, and the continuous flow method has a detection limit of 1.8μg / L, which is very close to the limit of volatile phenols of 2.0μg / L in "GB 5749-2022 Drinking Water Hygiene Standard". In chemical analysis methods, it is difficult to ensure the accuracy of the test results when the detection limit and quantification limit are very close. The current "GB 5009.295-2023 General Rules for Chemical Analysis Methods of National Food Safety Standards" stipulates that the quantitative limit of target analytes with limited values ​​should be 0.5 times or less of the limit value. Due to the special geographical environment of Tibet at high altitude, the national standard method is not very suitable for laboratories in Tibet, resulting in an increase in detection time, and the detection cycle is at least about 48 hours.

[0005] Due to Tibet's vast territory, large span, and diverse and complex geographical environment, its water quality safety monitoring tasks are large, and the adaptability of the detection methods is highly required. It is necessary for the Tibet Plateau Laboratory to develop highly compatible and efficient detection methods to provide new method references for Tibet's water quality detection and provide a technical research basis for the formulation of local standards. Summary of the invention

[0006] The present invention aims to provide an analytical method for rapidly determining volatile phenols in drinking natural water, so as to solve the problems in the prior art that there is no volatile phenol detection based on the characteristics of plateau water resources, sample pretreatment is required, many types of reagents are used, the amount of reagents is large, the toxicity of the reagents is high, the risk of environmental pollution is high, the detection cycle is long, and the cost is high.

[0007] In order to achieve the above object, the present invention provides the following method:

[0008] The present invention provides a method for rapidly determining volatile phenols in drinking natural water:

[0009] S1: equilibrate the volatile phenol standard solution in water to room temperature, accurately pipette the volatile phenol standard solution in water, make up to volume with ultrapure water, mix well, and obtain the volatile phenol standard working reserve intermediate solution in water;

[0010] S2: using ultrapure water to make up the volume of the standard working reserve intermediate solution of volatile phenol in water, and mixing the solution to obtain a standard working reserve solution of volatile phenol in water;

[0011] S3: placing the standard working stock solutions of volatile phenols in water in volumetric flasks of different capacities, and respectively making up the volumes to the scale lines of the volumetric flasks of different capacities with ultrapure water to obtain standard working solutions of volatile phenols in water of different concentrations;

[0012] S4: After the instrument conditions are balanced and stabilized by the water quality measuring instrument, the standard working solutions of volatile phenols in water with different concentrations are sampled and measured on the instrument, and the sample solution to be tested is tested to obtain the mass concentration of volatile phenols in the sample solution to be tested.

[0013] Preferably, the standard solution of volatile phenol in water is taken out and balanced to room temperature, the solution is accurately aspirated, and the volume is fixed with ultrapure water, and the dosage ratio of the standard solution of volatile phenol in water to the ultrapure water is 1:9.

[0014] Preferably, the standard working reserve intermediate solution of volatile phenols in water is accurately drawn and made up to volume with ultrapure water, and the usage ratio of the standard working reserve intermediate solution of volatile phenols in water to the ultrapure water is 1:99.

[0015] Preferably, 0.10 mL, 0.20 mL, 0.40 mL, 1.00 mL, 2.00 mL, 4.00 mL, and 10.0 mL of the standard working stock solution of volatile phenols in water are accurately pipetted into a 100 mL volumetric flask, and the volumes are respectively made up to the scale lines of the volumetric flasks of different capacities with ultrapure water to obtain standard working solutions of volatile phenols in water of different concentrations of 0.5 μg / L, 1.0 μg / L, 2.0 μg / L, 5.0 μg / L, 10.0 μg / L, 20.0 μg / L, and 50.0 μg / L.

[0016] Preferably, the multiple water quality measuring instruments include: chromatographic column: Shim-pack VP-ODS C18 liquid phase separation chromatographic column, 150mm×4.6mm, 5μm, or other chromatographic columns with equivalent analytical effects; detector: RF-20A fluorescence detector; column temperature: 35℃-45℃.

[0017] Preferably, the various water quality measuring instruments further include: mobile phase: methanol + ultrapure water = 55 + 45 (V:V); flow rate: 0.5 mL / min; detection wavelength 268 nm, emission wavelength 310 nm; injection volume: 20 μL.

[0018] Preferably, the sample solution to be tested is stored in a black sealed glass container, refrigerated at 2-4° C. and sealed to avoid light.

[0019] Preferably, the storage conditions of the sample solution to be tested also include: after the instrument conditions are balanced and stabilized by a water quality measuring instrument, the standard working solutions of volatile phenols in water with different concentrations are sampled and measured on the machine, and the sample solution to be tested is tested, and before the mass concentration of volatile phenols in the sample solution to be tested is obtained, the storage conditions also include: restoring the sample solution to be tested to room temperature of 18°C-22°C, shaking it evenly, and then filtering insoluble particulate impurities through a 0.22μm hydrophilic filter head.

[0020] Preferably, after the sample solution is tested, the corresponding peak area of ​​the sample solution is measured, and a standard curve is drawn with the mass concentration of the volatile phenol standard working solution in water as the abscissa and the corresponding peak area as the ordinate.

[0021] Preferably, the detection process of the sample solution to be tested is carried out according to the storage conditions of the sample solution to be tested, the chromatographic peak and the integrated frontal area of ​​the volatile phenol in the sample are qualitatively determined according to the retention time of the sample solution to be tested, and the mass concentration of the volatile phenol in the sample solution to be tested is obtained according to the standard curve.

[0022] The beneficial effects of the present invention are as follows: the detection limit of the present invention is 0.25 μg / L, and the quantitative limit of the method is 0.76 μg / L, which are lower than the detection limit of 2.0 μg / L of the national standard method; compared with the national standard detection method, the detection of the present invention has a short detection cycle, a small amount of reagents, and little environmental pollution. The average cycle is 15 minutes for one sample, the detection cost is low, the operation is simple, the accuracy is high, and the detection method is highly popularizable; the present invention establishes a method for quickly determining volatile phenols in Tibet's drinking natural water by high performance liquid chromatography-fluorescence detection, which has the advantages of simple operation, high accuracy, short detection cycle, etc., and has a lower detection limit. It is suitable for the detection of the content of volatile phenols (in terms of phenol) in drinking natural water, packaged drinking water and domestic drinking water in Tibet, reduces the detection cost of local water production enterprises in Tibet, and has good practicality and popularization for monitoring the content of volatile phenols (in terms of phenol) in domestic drinking water in Tibet, and contributes to the protection of Tibet's abundant water resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for the specific embodiments or the description of the prior art. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn according to the actual scale.

[0024] Figure 1 The present invention provides a flow chart of an analytical method for rapidly determining volatile phenols in drinking natural water.

[0025] Figure 2 It is a schematic diagram of an ultraviolet detector provided in an embodiment of the present invention.

[0026] Figure 3 It is a chromatogram comparison diagram of different proportions of methanol and water provided in an embodiment of the present invention, from left to right, 1-60:40, 2-55:45, 3-50:50, 4-40:60, and 5-30:70.

[0027] Figure 4 This is a comparison chart of chromatograms with different flow rates provided in an embodiment of the present invention, from left to right, they are 0.5 mL / min, 0.4 mL / min, 0.3 mL / min, (0.6 mL / min, 0.7 mL / min and later, the peak elution time is earlier and overlaps with the inverted peak. DETAILED DESCRIPTION

[0028] In order to make the technical personnel in the technical field better understand the scheme of the present invention, the technical scheme in the embodiment of the present invention will be clearly and completely described below in combination with the drawings in the embodiment of the present invention. Obviously, the described embodiment is only a part of the embodiment of the present invention, not all the embodiments. Based on the embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] The terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish different objects rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, device, product or end including a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units that are not listed, or may optionally include other steps or units inherent to these processes, methods, products or ends.

[0030] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0031] At present, the research progress of the detection methods of volatile phenols mainly includes 4-aminoantipyrine spectrophotometry, fully automatic flow injection method, gas chromatography-mass spectrometry, etc. These methods have both advantages and disadvantages, but none of them are targeted at the characteristics of water resources in the Tibetan Plateau and the geographical environment of the plateau laboratory. "GB 19298-2014 National Food Safety Standard Packaged Drinking Water", "GB 8537-2018 National Food Safety Standard Drinking Natural Mineral Water", "GB 5749-2022 Drinking Water Hygiene Standard", etc. have set limits on the content of volatile phenols (in terms of phenol) at 2.0ug / L. The detection methods for volatile phenols in "GB5750.4-2023 Standard Test Method for Drinking Water Part 4: Sensory Properties and Physical Indicators" and "GB 8538-2022 National Food Safety Standard Test Method for Drinking Natural Mineral Water" are 4-aminoantipyrine chloroform extraction spectrophotometry, flow injection method, and continuous flow method. These methods require sample pretreatment, use a variety of reagents, large reagent volumes, high reagent toxicity, high risk of environmental pollution, long detection cycle, and high cost. The national standard 4-aminoantipyrine chloroform extraction spectrophotometry and flow injection method have a detection limit of 2.0μg / L, and the continuous flow method has a detection limit of 1.8μg / L, which is very close to the limit of volatile phenols of 2.0μg / L in "GB 5749-2022 Drinking Water Hygiene Standard". In chemical analysis methods, it is difficult to ensure the accuracy of the test results when the detection limit and quantification limit are very close. The current "GB 5009.295-2023 General Rules for Chemical Analysis Methods of National Food Safety Standards" stipulates that the quantitative limit of target analytes with limited values ​​should be 0.5 times or less of the limit value. Due to the special geographical environment of Tibet at high altitude, the national standard method is not very suitable for laboratories in Tibet, resulting in an increase in detection time, and the detection cycle is at least about 48 hours.

[0032] Due to Tibet's vast territory, large span, and diverse and complex geographical environment, its water quality safety monitoring tasks are large, and the adaptability of the detection methods is highly required. It is necessary for the Tibet Plateau Laboratory to develop highly compatible and efficient detection methods to provide new method references for Tibet's water quality detection and provide a technical research basis for the formulation of local standards.

[0033] The present invention aims to provide an analytical method for rapidly determining volatile phenols in drinking natural water, so as to solve the problems in the prior art that there is no volatile phenol detection based on the characteristics of plateau water resources, sample pretreatment is required, many types of reagents are used, the amount of reagents is large, the toxicity of the reagents is high, the risk of environmental pollution is high, the detection cycle is long, and the cost is high.

[0034] The specific embodiment of the present invention provides a method for rapidly determining volatile phenols in drinking natural water. Figure 1 , Figure 2 , Figure 3 , Figure 4 As shown, the following steps are included:

[0035] S1: Equilibrate the standard solution of volatile phenol in water to room temperature, accurately pipette the standard solution of volatile phenol in water, make up to volume with ultrapure water, mix well, and obtain the standard working reserve intermediate solution of volatile phenol in water.

[0036] In the embodiment of the present invention, a standard solution of volatile phenol in water is taken out and balanced to room temperature, the solution is accurately aspirated, and the volume is fixed with ultrapure water, and the usage ratio of the standard solution of volatile phenol in water to ultrapure water is 1:9.

[0037] S2: For the standard working reserve intermediate solution of volatile phenol in water, use ultrapure water to make up the volume, mix well, and obtain the standard working reserve solution of volatile phenol in water.

[0038] In an embodiment of the present invention, the standard working reserve intermediate solution of volatile phenol in water is accurately aspirated, and the volume is fixed with ultrapure water, and the usage ratio of the standard working reserve intermediate solution of volatile phenol in water to ultrapure water is 1:99.

[0039] S3: Place the standard working stock solutions of volatile phenols in water in volumetric flasks of different capacities, and use ultrapure water to make up the volumes to the scale lines of the volumetric flasks of different capacities to obtain standard working solutions of volatile phenols in water of different concentrations.

[0040] In an embodiment of the present invention, 0.10 mL, 0.20 mL, 0.40 mL, 1.00 mL, 2.00 mL, 4.00 mL, and 10.0 mL of the standard working stock solution of volatile phenol in water are accurately pipetted into a 100 mL volumetric flask, and the volumes are respectively made up to the scale lines of the volumetric flasks of different capacities with ultrapure water to obtain standard working solutions of volatile phenol in water of different concentrations of 0.5 μg / L, 1.0 μg / L, 2.0 μg / L, 5.0 μg / L, 10.0 μg / L, 20.0 μg / L, and 50.0 μg / L.

[0041] S4: After the instrument conditions are balanced and stabilized by the water quality measuring instrument, the standard working solutions of volatile phenols in water with different concentrations are sampled and measured on the instrument, and the sample solutions to be tested are tested to obtain the mass concentration of volatile phenols in the sample solutions to be tested.

[0042] In an embodiment of the present invention, the water quality measuring instrument includes: chromatographic column: Shim-pack VP-ODS C18 liquid phase separation chromatographic column, 150mm×4.6mm, 5μm, or other chromatographic columns with equivalent analytical effects; detector: RF-20A fluorescence detector; column temperature: 35°C-45°C; the water quality measuring instrument also includes: mobile phase: methanol + ultrapure water = 55+45 (V:V); flow rate: 0.5mL / min; detection wavelength 268nm, emission wavelength 310nm; injection volume: 20μL; the sample solution to be tested is stored in a black sealed glass container, refrigerated and sealed at 2-4°C to avoid light; the storage conditions of the sample solution to be tested also include: after the instrument conditions are balanced and stabilized by the water quality measuring instrument, the standard working solutions of volatile phenols in water of different concentrations are sampled and measured on the machine, and the samples to be tested are tested. The method of testing the sample solution to obtain the mass concentration of volatile phenol in the sample solution to be tested also includes: restoring the sample solution to be tested to room temperature of 18°C-22°C, shaking it evenly, and then filtering insoluble particulate impurities through a 0.22μm hydrophilic filter head; after the sample solution to be tested is tested, the corresponding peak area of ​​the sample solution to be tested is measured, and a standard curve is drawn with the mass concentration of the volatile phenol standard working solution in water as the horizontal coordinate and the corresponding peak area as the vertical coordinate; the detection process of the sample solution to be tested is carried out according to the storage conditions of the sample solution to be tested, and the chromatographic peak and the integrated frontal area of ​​the volatile phenol in the sample to be tested are qualitatively determined according to the retention time of the sample solution to be tested, and the mass concentration of the volatile phenol in the sample solution to be tested is obtained according to the standard curve.

[0043] Embodiment 1

[0044] Experimental procedure: Standard working stock solution of volatile phenol in water (0.50 mg / L): Take out the standard solution of volatile phenol in water (500.0 mg / L) and equilibrate it to room temperature, accurately pipette 10.0 mL of the solution, dilute to 100.0 mL with ultrapure water, mix well, and obtain a 50.0 mg / L standard working stock intermediate solution of volatile phenol in water. Accurately pipette 1.0 mL of the standard working stock intermediate solution of volatile phenol in water (50.0 mg / L), dilute to 100.0 mL with ultrapure water, mix well, and obtain a 0.50 mg / L standard working stock solution of volatile phenol in water.

[0045] Standard working solution of volatile phenol in water: Accurately pipette 0.10mL, 0.20mL, 0.40mL, 1.00mL, 2.00mL, 4.00mL, and 10.0mL of the standard working stock solution of volatile phenol in water (0.50mg / L) into a 100mL volumetric flask and dilute to the scale with ultrapure water to obtain 0.5μg / L, 1.0μg / L, 2.0μg / L, 5.0μg / L, 10.0μg / L, 20.0μg / L, and 50.0μg / L standard working solutions of volatile phenol in water.

[0046] Instruments used: Chromatographic column: Shim-pack VP-ODS C18 liquid phase separation chromatographic column, 150mm×4.6mm, 5μm, or other chromatographic columns with equivalent analytical effects; detector: RF-20A fluorescence detector; column temperature: 40°C; mobile phase: methanol + ultrapure water = 55+45 (V:V); flow rate: 0.5mL / min; detection wavelength 268nm, emission wavelength 310nm; injection volume: 20μL.

[0047] After the instrument is balanced and stabilized according to the above instrument reference conditions, the standard working solution of volatile phenol in water is injected into the machine for measurement, and the corresponding peak area is measured. A standard curve is drawn with the mass concentration of the standard working solution as the horizontal axis and the peak area as the vertical axis.

[0048] Water samples should be stored in black bottles or sealed glass containers, refrigerated and sealed at 2-4°C, away from light. Before testing, water samples should be restored to room temperature (20±2°C), and must be fully shaken and then filtered through a 0.22μm hydrophilic filter (Jin Teng PSE) to remove insoluble particulate impurities and protect the chromatographic column to reduce interference; the sample solution is tested under the same conditions as above, and the chromatographic peak of volatile phenols in the sample is qualitatively determined according to the retention time of the standard sample, and the peak area is integrated, and the mass concentration of volatile phenols in the sample solution to be tested is obtained according to the standard curve.

[0049] Experimental results: (1) Detector selection: The experiment compared the UV detector and found that it had no peaks, while the fluorescence detector had good peaks (such as Figure 2 shown);

[0050] (2) Selection of detection wavelength: The volatile phenol (in terms of phenol) standard substance in water was scanned by spectrophotometer to determine the maximum absorption wavelength of 268 nm;

[0051] (3) Selection of mobile phase: The mobile phases of methanol and water, acetonitrile and water were compared. The results showed that the chromatogram of the mobile phase of methanol and water had a good peak shape of volatile phenols and no interference from other peaks.

[0052] (4) Ratio of mobile phase: The test compared the volume ratio of methanol to water at 30:70, 40:60, 50:50, 60:40, 55:45, etc. The results showed that the peak shape was the best when the ratio of methanol to water was 55:45, and the integrated peak area was the largest; (e.g. Figure 3 (shown)

[0053] (5) Selection of flow rate: The test compared flow rates of 0.3 mL / min, 0.4 mL / min, 0.5 mL / min, 0.6 mL / min, and 0.7 mL / min. The results showed that the peak shape and peak time were best when the flow rate was 0.5 mL / min; (e.g. Figure 4(shown)

[0054] (6) The experiment selected the specifications and models of the chromatographic column and optimized the detection time.

[0055] Standard working curve, method detection limit and quantification limit:

[0056] According to the instrument working parameter settings, balance the instrument, accurately pipette the standard series working solutions into the injection bottle, measure them on the machine in turn, draw the standard curve, and obtain the standard curve of volatile phenol (calculated as phenol): f(x)=4.14515e-005*x-0.101754, the correlation coefficient R is 0.9999968, and the linearity is good.

[0057] According to GB 5009.295-2023 General Rules for Chemical Analysis Methods of National Food Safety Standards, this test method uses the instrument's 3 times signal-to-noise ratio to calculate the method's detection limit, and uses the instrument's 10 times signal-to-noise ratio to calculate the method's quantification limit, and the method's detection limit and quantification limit of this test are obtained to be 0.25 μg / L and 0.76 μg / L, respectively. For method detection limit verification, packaged drinking water was used as the blank sample matrix, and phenol standard solution was spiked at a concentration of 0.25 μg / L. According to the conditions of this test method, 20 blank samples were spiked and measured in parallel. The probability of volatile phenol detection was 100%, the spike recovery rate was 86.0% to 98.4%, and the spiked RSD value was 4.60%, which met the requirements of GB5009.295-2023. The results are shown in Table 1.

[0058] According to GB5749-2022, GB8537-2018 and GB 19298-2014, the limit value of volatile phenol (in terms of phenol) is 2.0 μg / L. The detection limit and quantification limit of this test method are lower than the national standard limit value and can meet the requirements of the standard. The minimum detection concentration of volatile phenol (in terms of phenol) in the national standard detection method is 2.0 μg / L. The detection limit of this method is better than the national standard.

[0059] Table 1 Method detection limit and method quantification limit

[0060]

[0061] Recovery and precision test

[0062] According to GB 5009.295-2023 General Rules for Chemical Analysis Methods of National Food Safety Standard, phenol standard solution was spiked, and three different concentrations were spiked into three water sample matrices, namely packaged drinking water, mineral water, and drinking water, which were 0.75 μg / L around the method quantification limit, 2.0 μg / L of the national limit, and 20 μg / L of high concentration. The sample solutions of different spiked concentrations of the three water sample matrices were measured in parallel 6 times, and the corresponding spiked recoveries and relative standard deviations (RSD) were calculated. The results are shown in Tables 2, 3, and 4. The results show that the spiked recovery and precision of this method are good, meeting the technical requirements for the confirmation of the GB5009.295-2023 test method and the actual needs of the test.

[0063] Table 2 Packaged drinking water spike recovery and precision test results (n = 6)

[0064]

[0065]

[0066] Table 3 Recovery and precision test results of mineral water spike (n = 6)

[0067]

[0068] Table 4 Recovery and precision test results of drinking water spike (n=6)

[0069]

[0070] Accuracy test

[0071] According to this method, the content of volatile phenol (in terms of phenol) in drinking water of two different concentrations of quality control samples from the Environmental Standard Sample Institute of the Ministry of Ecology and Environment and China Food and Drug Administration was tested, and the parallel determination was performed three times. The average value and Z value were calculated. The results are shown in Table 5. The test values ​​are all within the satisfactory value range of the quality control samples and are close to the specified value. According to this method, the measurement audit of China Food and Drug Administration was carried out, and the Z value was 0.67. The measurement audit was passed, and the test results were within the satisfactory value range. This shows that the accuracy of this method is good and meets the requirements of detection and analysis.

[0072] Table 5 Determination results of volatile phenol (in terms of phenol) content in quality control samples (n=3)

[0073]

[0074] Analysis of natural drinking water and drinking water in Tibet

[0075] The established test method was used to monitor and determine the content of volatile phenol (in terms of phenol) in different types of natural drinking water and drinking water in 10 places in Tibet. Each water sample was measured twice in parallel and the average value was taken. The test results are shown in Table 6. The results show that the determination results of volatile phenol (in terms of phenol) in natural drinking water and drinking water were not detected, indicating that the water sources in these 10 places in Tibet were not contaminated by volatile phenol (in terms of phenol).

[0076] Table 6 Test results of volatile phenol (in terms of phenol) in natural drinking water and drinking water in Tibet

[0077]

[0078] The beneficial effects of the present invention are as follows: the detection limit of the present invention is 0.25 μg / L, and the quantitative limit of the method is 0.76 μg / L, which are lower than the detection limit of 2.0 μg / L of the national standard method; compared with the national standard detection method, the detection of the present invention has a short detection cycle, a small amount of reagents, and little environmental pollution. The average cycle is 15 minutes for one sample, the detection cost is low, the operation is simple, the accuracy is high, and the detection method is highly popularizable; the present invention establishes a method for quickly determining volatile phenols in Tibet's drinking natural water by high performance liquid chromatography-fluorescence detection, which has the advantages of simple operation, high accuracy, short detection cycle, etc., and has a lower detection limit. It is suitable for the detection of the content of volatile phenols (in terms of phenol) in drinking natural water, packaged drinking water and domestic drinking water in Tibet, reduces the detection cost of local water production enterprises in Tibet, and has good practicality and popularization for monitoring the content of volatile phenols (in terms of phenol) in domestic drinking water in Tibet, and contributes to the protection of Tibet's abundant water resources.

[0079] The above is only an embodiment of the present invention, and the common knowledge such as the known specific technical schemes or characteristics in the scheme is not described in detail here; it should be pointed out that for those skilled in the art, several modifications and improvements can be made without departing from the scheme of the present invention, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the present invention and the practicality of the patent. The protection scope required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A method for rapidly determining volatile phenols in drinking natural water, characterized in that: The method comprises: S1: equilibrate the volatile phenol standard solution in water to room temperature, accurately pipette the volatile phenol standard solution in water, make up to volume with ultrapure water, mix well, and obtain the volatile phenol standard working reserve intermediate solution in water; S2: using ultrapure water to make up the volume of the standard working reserve intermediate solution of volatile phenol in water, and mixing the solution to obtain a standard working reserve solution of volatile phenol in water; S3: placing the standard working stock solutions of volatile phenols in water in volumetric flasks of different capacities, and respectively making up the volumes to the scale lines of the volumetric flasks of different capacities with ultrapure water to obtain standard working solutions of volatile phenols in water of different concentrations; S4: After the instrument conditions are balanced and stabilized by the water quality measuring instrument, the standard working solutions of volatile phenols in water with different concentrations are sampled and measured on the instrument, and the sample solution to be tested is tested to obtain the mass concentration of volatile phenols in the sample solution to be tested.

2. The method for rapidly determining volatile phenols in drinking natural water according to claim 1, characterized in that: The standard solution of volatile phenol in water is taken out and balanced to room temperature, the solution is accurately aspirated, and the volume is fixed with ultrapure water, and the usage ratio of the standard solution of volatile phenol in water to the ultrapure water is 1:

9.

3. The method for rapidly determining volatile phenols in drinking natural water according to claim 1, characterized in that: The standard working reserve intermediate solution of volatile phenol in water is accurately drawn and fixed to volume with ultrapure water, and the usage ratio of the standard working reserve intermediate solution of volatile phenol in water to the ultrapure water is 1:

99.

4. The method for rapidly determining volatile phenols in drinking natural water according to claim 1, characterized in that: Accurately pipette 0.10mL, 0.20mL, 0.40mL, 1.00mL, 2.00mL, 4.00mL, and 10.0mL of the standard working stock solution of volatile phenol in water into a 100mL volumetric flask, and dilute to the scale lines of the volumetric flasks of different capacities with ultrapure water to obtain standard working solutions of volatile phenol in water of different concentrations of 0.5μg / L, 1.0μg / L, 2.0μg / L, 5.0μg / L, 10.0μg / L, 20.0μg / L, and 50.0μg / L.

5. The method for rapidly determining volatile phenols in drinking natural water according to claim 1, characterized in that: The water quality measuring instrument comprises: chromatographic column: Shim-pack VP-ODS C18 liquid phase separation chromatographic column, 150 mm×4.6 mm, 5 μm, or other chromatographic columns with equivalent analytical effects; detector: RF-20A fluorescence detector; column temperature: 35°C-45°C.

6. The method for rapidly determining volatile phenols in drinking natural water according to claim 5, characterized in that: The water quality measuring instrument also includes: mobile phase: methanol + ultrapure water = 55 + 45 (V:V); flow rate: 0.5 mL / min; detection wavelength 268 nm, emission wavelength 310 nm; injection volume: 20 μL.

7. The method for rapidly determining volatile phenols in drinking natural water according to claim 1, characterized in that: The storage conditions of the sample solution to be tested are: The sample solution to be tested is stored in a black sealed glass container, refrigerated at 2-4° C. and sealed to avoid light.

8. The method for rapidly determining volatile phenols in drinking natural water according to claim 7, characterized in that: The storage conditions of the sample solution to be tested also include: After the instrument conditions are balanced and stabilized by a water quality measuring instrument, the standard working solutions of volatile phenols in water with different concentrations are sampled and measured on the machine, and the sample solution to be tested is tested. Before obtaining the mass concentration of volatile phenols in the sample solution to be tested, the method also includes: restoring the sample solution to be tested to room temperature of 18°C-22°C, shaking it evenly, and then filtering insoluble particulate impurities through a 0.22μm hydrophilic filter head.

9. The method for rapidly determining volatile phenols in drinking natural water according to claim 8, characterized in that: After the sample solution is tested, the corresponding peak area of ​​the sample solution is measured, and a standard curve is drawn with the mass concentration of the volatile phenol standard working solution in water as the abscissa and the corresponding peak area as the ordinate.

10. The method for rapidly determining volatile phenols in drinking natural water according to claim 9, characterized in that: The detection process of the sample solution to be tested is carried out according to the storage conditions of the sample solution to be tested, the chromatographic peak and the integrated frontal area of ​​the volatile phenol in the sample are qualitatively determined according to the retention time of the sample solution to be tested, and the mass concentration of the volatile phenol in the sample solution to be tested is obtained according to the standard curve.

Images