阅读说明：本技术 1,5-萘二磺酸二钠盐替代石油标准物校准水中石油传感器的方法 (Method for calibrating underwater petroleum sensor by replacing petroleum standard with disodium 1, 5-naphthalenedisulfonate ) 是由 张丽 曹煊 孔祥峰 马海宽 吴宁 王阳 王婧茹 刘岩 王昭玉 于 2020-03-20 设计创作，主要内容包括：本发明属于海洋环境监测技术领域,涉及一种水中石油传感器的校准方法。该方法包括：(1)配制一系列梯度浓度的石油标准物质,绘制荧光峰的荧光值对石油标准物浓度工作曲线；(2)配制一系列梯度浓度的1,5-萘二磺酸二钠盐溶液,绘制荧光峰的荧光值对1,5-萘二磺酸二钠盐溶液浓度工作曲线；(3)根据石油标准物浓度工作曲线与1,5-萘二磺酸二钠盐溶液浓度工作曲线,计算出石油标准物质浓度与1,5-萘二磺酸二钠盐溶液浓度的换算关系；(4)利用1,5-萘二磺酸二钠盐对水中石油传感器进行校准,依据所述的换算关系计算出传感器校准方程。本发明与现有技术相比,采用易溶于水的化学试剂1,5-萘二磺酸二钠盐来代替石油标准物质,缩短实验操作时长,减少对操作人员身体的伤害。(The invention belongs to the technical field of marine environment monitoring, and relates to a calibration method of an underwater oil sensor. The method comprises the following steps: (1) preparing a series of petroleum standard substances with gradient concentration, and drawing a working curve of the fluorescence value of a fluorescence peak to the concentration of the petroleum standard substances; (2) preparing a series of 1, 5-naphthalene disulfonate disodium salt solutions with gradient concentrations, and drawing a working curve of the fluorescence value of a fluorescence peak to the concentration of the 1, 5-naphthalene disulfonate disodium salt solution; (3) calculating the conversion relation between the concentration of the petroleum standard substance and the concentration of the 1, 5-disodium naphthalenedisulfonate salt solution according to the concentration working curve of the petroleum standard substance and the concentration working curve of the 1, 5-disodium naphthalenedisulfonate salt solution; (4) and (3) calibrating the petroleum sensor in water by using 1, 5-naphthalene disulfonate disodium salt, and calculating a sensor calibration equation according to the conversion relation. Compared with the prior art, the chemical reagent 1, 5-naphthalene disulfonic acid disodium salt which is easy to dissolve in water is adopted to replace petroleum standard substances, so that the experimental operation time is shortened, and the harm to the bodies of operators is reduced.)

A method for calibrating a petroleum sensor in water by replacing a petroleum standard with 1, 5-naphthalenedisulfonic acid disodium salt, comprising:

(1) preparing a series of petroleum standard substances with gradient concentration, and drawing a working curve of the fluorescence value of a fluorescence peak to the concentration of the petroleum standard substances;

(2) preparing a series of 1, 5-naphthalene disulfonate disodium salt solutions with gradient concentrations, and drawing a working curve of the fluorescence value of a fluorescence peak to the concentration of the 1, 5-naphthalene disulfonate disodium salt solution;

(3) calculating the conversion relation between the concentration of the petroleum standard substance and the concentration of the 1, 5-disodium naphthalenedisulfonate salt solution according to the concentration working curve of the petroleum standard substance and the concentration working curve of the 1, 5-disodium naphthalenedisulfonate salt solution;

(4) the method comprises the steps of utilizing 1, 5-disodium naphthalene disulfonate to calibrate the petroleum sensor in water, and calculating a sensor calibration equation according to the conversion relation between the concentration of a petroleum standard substance and the concentration of the 1, 5-disodium naphthalene disulfonate solution.

2. The method of calibrating an in-water petroleum sensor using disodium 1, 5-naphthalenedisulfonate as a surrogate petroleum standard according to claim 1 wherein the regression equation for the working curve of petroleum standard concentration is: 579.75x +82.463, (R)²＝0.9914)。

3. The method of calibrating a petroleum sensor in water using 1, 5-naphthalenedisulfonic acid disodium salt as a substitute for a petroleum standard according to claim 2 wherein the regression equation of the working curve for the concentration of the 1, 5-naphthalenedisulfonic acid disodium salt solution is: 0.5632x +39.302, (R)²＝0.9977)。

4. The method for calibrating an in-water petroleum sensor using disodium 1, 5-naphthalenedisulfonate as a substitute for a petroleum standard according to claim 3, wherein the step of deriving the conversion of the concentration of the petroleum standard to the concentration of disodium 1, 5-naphthalenedisulfonate salt solution comprises:

respectively calculating fluorescence values corresponding to the concentrations of a group of petroleum standards according to the working curve of the petroleum standards;

calculating the concentration of the 1, 5-naphthalenedisulfonic acid disodium salt solution corresponding to the concentration fluorescence value of each petroleum standard substance according to the 1, 5-naphthalenedisulfonic acid disodium salt working curve;

obtaining a regression equation between the concentration of the petroleum standard substance and the concentration of the 1, 5-naphthalenedisulfonic acid disodium salt solution: 0.9715 x-0.0744 (R)²1) where y is the petroleum standard concentration and x is the 1, 5-naphthalenedisulfonic acid disodium salt solution concentration.

5. The method for calibrating an in-water petroleum sensor using 1, 5-naphthalenedisulfonic acid disodium salt as a substitute for a petroleum standard according to any one of claims 1-4, wherein the fluorometric conditions of the petroleum standard working curve and the 1, 5-naphthalenedisulfonic acid disodium salt solution working curve are: excitation wavelength 254nm, emission wavelength 360 nm.

Technical Field

The invention belongs to the technical field of marine environment monitoring, and relates to a calibration method of an underwater oil sensor.

Background

With the development of oceans, environmental pollution is becoming more serious. In particular, in recent years, serious environmental disasters such as oil leakage in gulf of mexico, oil leakage in the great company and oil leakage in Bohai gulf of sea are frequent, pollution to marine ecological environment in the production process of an offshore platform and oil leakage generated in the process of marine oil transportation bring serious harm to the marine ecological environment, and huge loss is caused to economy of surrounding provinces and cities. The problem of marine oil contamination has attracted considerable attention. The monitoring capability of marine crude oil pollutants is improved, and particularly the on-site, real-time and continuous monitoring and analyzing capability of petroleum pollutants is enhanced.

At present, the field sampling-laboratory analysis and in-situ sensor monitoring are mainly used for marine crude oil detection and analysis, the laboratory method mainly comprises an ultraviolet spectrophotometry, an infrared spectrophotometry, a fluorescence spectrophotometry, a gravimetric method, a gas phase-mass spectrometry combined method and the like, the analysis result of the laboratory method is more accurate, but the pretreatment process is more complicated, the requirement on the storage condition of the sample is strict, the sample is easily influenced by the conditions of temperature, light and the like, and meanwhile, the organic solvent is used, so that the physical injury to experimental operators is easily caused, and the secondary pollution to the environment is easily caused. The in-situ sensor monitoring has the advantages of high sensitivity, real-time measurement, simple operation, no need of chemical reagents, no damage to organisms and the like, and becomes a method for measuring crude oil in water bodies widely.

The petroleum in-situ sensor monitors fluorescent substances in the crude oil. The fluorescence of crude oil is mainly caused by aromatic hydrocarbon compounds, which are important components in crude oil and oil-producing rock, generally account for 10% -45% of total hydrocarbons and consist of hundreds of compounds. The aromatic hydrocarbon refers to a compound containing a benzene ring, belongs to unsaturated hydrocarbon, and is divided into monocyclic ring, polycyclic ring (independent benzene ring) and condensed ring (benzene ring shares adjacent carbon atoms). When the aromatic hydrocarbon compound is influenced by environmental factors such as mixing of different types of aromatic hydrocarbon compounds, substituent groups, halogen elements, metal cations, solvents, temperature, hydrogen bonds and the like, the position of a fluorescence peak and fluorescence intensity are changed. Crude oil can be separated into saturated hydrocarbon, aromatic, non-hydrocarbon and asphaltene 4 fractions. The fluorescence of crude oil is the result of a combination of the fluorescence of these 4 ethnic groups. Aromatic and non-hydrocarbons play a dominant role in crude oil fluorescence because saturated hydrocarbons do not fluoresce and asphaltenes fluoresce too weakly.

At present, a common laboratory method for monitoring petroleum is GB17378.4-2007, the method is long in operation time, and organic reagents are used, so that harm is easily caused to the bodies of operators. The components of the crude oil are complex, the components of the contained fluorescent substances are also different, the crude oil with the same concentration has different possibly generated fluorescence intensities, the calibration work of the petroleum sensor in water is very complex, and the accuracy of the calibrated sensor is not high, so that a method needs to be established to enable the fluorescence signal value acquired by the sensor to be accurately converted into the actual concentration of the crude oil, the accuracy of the sensor is improved, and the complex procedures of the calibration work are reduced.

Disclosure of Invention

In order to solve the problems and the defects of the existing calibration method of the underwater petroleum sensor, the invention provides a method for calibrating the petroleum sensor by using a water-soluble compound to replace a petroleum standard substance, wherein the compound is easy to dissolve in water, has good fluorescence efficiency under the petroleum fluorescence detection wavelength, and has stable property and low toxicity.

The technical scheme adopted by the invention for solving the technical problems is as follows: a method for calibrating a petroleum sensor in water using 1, 5-naphthalenedisulfonic acid disodium salt in place of a petroleum standard comprising:

(1) preparing a series of petroleum standard substances with gradient concentration, and drawing a working curve of the fluorescence value of a fluorescence peak to the concentration of the petroleum standard substances;

(2) preparing a series of 1, 5-naphthalene disulfonate disodium salt solutions with gradient concentrations, and drawing a working curve of the fluorescence value of a fluorescence peak to the concentration of the 1, 5-naphthalene disulfonate disodium salt solution;

(3) calculating the conversion relation between the concentration of the petroleum standard substance and the concentration of the 1, 5-disodium naphthalenedisulfonate salt solution according to the concentration working curve of the petroleum standard substance and the concentration working curve of the 1, 5-disodium naphthalenedisulfonate salt solution;

(4) the method comprises the steps of utilizing 1, 5-disodium naphthalene disulfonate to calibrate the petroleum sensor in water, and calculating a sensor calibration equation according to the conversion relation between the concentration of a petroleum standard substance and the concentration of the 1, 5-disodium naphthalene disulfonate solution.

Further, the regression equation of the concentration working curve of the petroleum standard substance is as follows: 579.75x +82.463, (R)²＝0.9914)。

Further, the regression equation of the working curve of the concentration of the 1, 5-naphthalenedisulfonic acid disodium salt is as follows: 0.5632x +39.302, (R)²＝0.9977)。

Further, the derivation step of the conversion relation between the concentration of the petroleum standard substance and the concentration of the 1, 5-naphthalenedisulfonate disodium salt solution is as follows: respectively calculating fluorescence values corresponding to the concentrations of a group of petroleum standards according to the concentration working curve of the petroleum standards;

calculating the concentration of the 1, 5-naphthalenedisulfonic acid disodium salt solution corresponding to each concentration fluorescence value of the petroleum standard substance according to the working curve of the concentration of the 1, 5-naphthalenedisulfonic acid disodium salt solution;

obtaining a regression equation between the concentration of the petroleum standard substance and the concentration of the 1, 5-naphthalenedisulfonic acid disodium salt solution: 0.9715 x-0.0744 (R)²1) where y is the petroleum standard concentration and x is the 1, 5-naphthalenedisulfonic acid disodium salt solution concentration.

In a preferred embodiment of the present invention, the fluorescence measurement conditions of the concentration working curve of the petroleum standard substance and the concentration working curve of the disodium 1, 5-naphthalenedisulfonate solution are as follows: the excitation wavelength is 254nm and the emission wavelength is 360 nm.

Compared with the prior art, the method adopts the water-soluble chemical reagent 1, 5-naphthalene disulfonic acid disodium salt to replace the petroleum standard substance, does not use an organic reagent in the experimental process, and reduces the measurement error caused by the decomposition of petroleum in the water-soluble oscillation process. According to the conversion relation of the concentration of the 1, 5-naphthalenedisulfonic acid disodium salt and petroleum under the measuring wavelength, the conversion formula can be directly referred to, the experimental operation time is shortened, and the harm to the bodies of operators is reduced.

Drawings

FIG. 1 is a spectrum of a petroleum standard substance and disodium 1, 5-naphthalenedisulfonate;

FIG. 2 is a petroleum standard concentration work curve;

FIG. 3 is a working curve of the 1, 5-naphthalenedisulfonic acid disodium salt concentration.

Detailed Description

In order to facilitate an understanding of the invention, the invention is described in more detail below with reference to the accompanying drawings and specific examples. Preferred embodiments of the present invention are shown in the drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

In this embodiment, a 1, 5-naphthalenedisulfonic acid disodium salt which is easily soluble in water is used to replace a petroleum standard substance to calibrate the petroleum sensor in water, and the specific steps are as follows:

1. preparing a series of marine environment monitoring petroleum component analysis standard substances with gradient concentration, performing fluorescence detection under the conditions of excitation wavelength of 254nm and emission wavelength of 360nm according to a fluorescence spectrophotometer method specified in GB17378.4-2007, and scanning a full spectrum to obtain a spectrogram of the petroleum standard substance, wherein the spectrogram is shown in figure 1.

Determining a working curve of the fluorescence value of the fluorescence peak to the concentration of the petroleum standard substance as follows: 579.75x +82.463, (R)²0.9914) as shown in fig. 2.

2. Preparing a series of 1, 5-naphthalenedisulfonic disodium salt solutions with gradient concentrations, performing fluorescence detection under the conditions that the excitation wavelength is 254nm and the emission wavelength is 360nm, and scanning a full spectrum to obtain a spectrogram of the 1, 5-naphthalenedisulfonic disodium salt, which is shown in figure 1.

Determining the working curve of the fluorescence value of the fluorescence peak to the concentration of the 1, 5-naphthalenedisulfonic acid disodium salt solution as follows: 0.5632x +39.302, (R)²0.9977). See fig. 3.

Referring to FIG. 1, under the same experimental conditions: the excitation wavelength is 254nm, the emission wavelength is 360nm, and the disodium 1, 5-naphthalenedisulfonate has a fluorescence effect at the wavelength of 360nm, so that the disodium 1, 5-naphthalenedisulfonate can be used for replacing a petroleum standard substance to calibrate the oil-in-water sensor.

3. Deducing the conversion relation between the concentration of the petroleum standard substance and the concentration of the 1, 5-naphthalenedisulfonate disodium salt solution:

(1) according to the working curve y of the concentration of the petroleum standard substance, 579.75x +82.463, (R)²0.9914), the fluorescence values for a set of petroleum standard concentrations were calculated, respectively, as shown in table 1.

TABLE 1 Petroleum Standard concentrations and corresponding fluorescence values

(2) According to the working curve of the concentration of the 1, 5-naphthalenedisulfonic acid disodium salt solution, the fluorescence values in the table 1 are substituted into the following values in sequence: 0.5632x +39.302, (R)²0.9977), the concentrations of disodium 1, 5-naphthalenedisulfonate salt solution were calculated for each fluorescence value in table 1, and are shown in table 2.

TABLE 2 fluorescence values and corresponding concentrations of disodium 1, 5-naphthalenedisulfonate salt in solution

(3) According to the calculation results of (1) and (2), obtaining a regression equation between the concentration of the petroleum standard substance and the concentration of the 1, 5-naphthalenedisulfonic acid disodium salt solution: 0.9715 x-0.0744 (R)²1) where y is the petroleum standard concentration and x is the 1, 5-naphthalenedisulfonic acid disodium salt solution concentration.

(4) By utilizing the conversion relation between the concentration of the petroleum standard substance and the concentration of the 1, 5-naphthalenedisulfonic acid disodium salt solution, the 1, 5-naphthalenedisulfonic acid disodium salt can be used for replacing the petroleum standard substance to calibrate and calibrate the petroleum in-situ sensor, and a calibration and calibration equation of the petroleum sensor is calculated.

By adopting the method, the standard petroleum sample is determined after the underwater petroleum sensor is calibrated to carry out verification test:

(1) petroleum standard samples were prepared with concentration gradients of 0 mg/L, 0.1 mg/L, 0.2 mg/L, 0.4 mg/L, 0.8 mg/L, 1.6 mg/L, 3.2 mg/L, 6.4 mg/L.

(2) By regression equation between oil standard concentration and 1, 5-naphthalenedisulfonic acid disodium salt concentration: 0.9715 x-0.0744 (R)²1), calculating the concentration of 1, 5-naphthalenedisulfonic acid disodium salt to be prepared, and preparing a 1, 5-naphthalenedisulfonic acid disodium salt solution gradient;

(3) calibrating the petroleum sensor in water with the calculated gradient concentration 1, 5-naphthalenedisulfonic acid disodium salt solution:

and (3) measuring by using an uncalibrated sensor to obtain fluorescence values corresponding to various concentrations of the 1, 5-naphthalenedisulfonic acid disodium salt solution to obtain a working curve, and calculating and deducing a calibration equation of the petroleum sensor in the water according to a regression equation between the concentration of the petroleum standard substance and the concentration of the 1, 5-naphthalenedisulfonic acid disodium salt solution.

(4) Testing the calibrated sensor, measuring the petroleum standard substance with known concentration by using the calibrated sensor, and calculating the relative error; the results are shown in Table 3:

TABLE 3 sensor validation results after calibration with 1, 5-naphthalenedisulfonic acid disodium salt

The result shows that the relative error of the result of the sensor measuring sample calibrated and calibrated by the method is within 15 percent, which indicates that the method is feasible.