Rapid measurement method for trace silicates and phosphate radicals

Abstract

The invention relates to a method for rapidly measuring trace silicate radicals and phosphate radicals. The method comprises the following steps: respectively implementing corresponding linear calibration methods or nonlinear calibration methods under two reaction systems on the basis of determining that a current calibration environment is a low-concentration linear calibration stage or a high-concentration nonlinear calibration stage, and obtaining corresponding calibration data; the reaction systems are respectively a first reaction system and a second reaction system which are distinguished according to a high-pressure value and reaction time of the chemiluminescence instrument; the nonlinear calibration method is realized based on a transition probability P and a quenching parameter K; and rapid measurement of trace silicates and phosphate radicals is carried out based on calibration data and a reaction system. The invention also discloses a system and a device for rapidly measuring the trace silicates and phosphate radicals, the contents of the trace silicates and phosphate radicals in water can be simultaneously detected by utilizing the time difference and the luminous intensity difference of the phosphate radicals and the silicates in reaction, and on the basis of accurately quantifying the phosphate radicals, the detection accuracy is greatly improved. The measurement influence of phosphate radicals on silicate radicals in a chemiluminescence method is eliminated.

Description

Technical Field

[0001] The invention relates to the technical field of calibration of analytical instruments, and in particular to a method for quickly measuring trace silicate and phosphate. Background Art

[0002] The treatment and monitoring of boiler water in thermal power plants is crucial, directly impacting safe boiler operation, energy efficiency, and the overall economic performance of the power plant. The presence of silicate ions is one of the primary causes of boiler scale formation. Silicate scale has a complex chemical composition, primarily consisting of aluminum and iron silicate compounds. This scale uniformly coats the inner walls of boiler tubes and the low-pressure cylinder blades of steam turbines. Because silicate scale has a thermal conductivity far lower than that of metal, its presence can severely impact the boiler's heat transfer efficiency, leading to heat loss and localized overheating, and in severe cases, even causing boiler damage. Boiler feedwater treatment typically requires a SiO2 content below 20 μg / L to ensure boiler water purity and stability. Excessive silicate levels in boiler water not only contaminate steam, causing deposits inside turbines and reducing equipment efficiency, but can also corrode the boiler's metal components, threatening safe operation.

[0003] Currently, most thermal power plants and the semiconductor industry primarily use silicate analyzers based on the molybdenum blue colorimetric principle to measure silicate ion concentration. This process requires manual addition of a reagent, followed by a chemical color reaction, followed by measurement using the silicate analyzer. This process has a low degree of automation, prolonged testing time, and significant human influence. Chemiluminescence-based silicate analyzers offer high sensitivity, require no external excitation light source, eliminate background and stray light interference, and exhibit low noise, making them an effective method for rapidly analyzing silicate concentration in water.

[0004] However, chemiluminescence is affected by phosphate when measuring silicate. Phosphomolybdic heteropolyacids, formed when phosphate reacts with ammonium molybdate, can also cause the luminol reagent to emit light, affecting silicate measurement. Unlike the traditional silicomolybdenum blue colorimetric method, which can eliminate the phosphate effect by adding a masking agent, chemiluminescence is an instantaneous luminescence reaction. Adding a masking agent changes the luminescence conditions, thus affecting silicate measurement. The inability to eliminate the phosphate effect is the greatest drawback of chemiluminescence for silicate measurement.

[0005] In summary, the existing technology has the following technical defects:

[0006] (1) Phosphate and silicate have similar chemical properties. Both can form corresponding heteropolyacids in the acidic ammonium molybdate system. Both can make luminol emit light. Therefore, the chemiluminescence method for measuring silicate cannot eliminate the influence of phosphate.

[0007] (2) Although oxalic acid can inhibit the combination of phosphate and ammonium molybdate as an inhibitor, the addition of oxalic acid changes the environment of the chemical reaction, causing the luminescence intensity of luminol oxidized by silicomolybdate to change, which reduces the measurement accuracy. Therefore, the use of a masking agent will greatly reduce the accuracy of silicate measurement. Summary of the Invention

[0008] The purpose of the present invention is to provide a method for rapid measurement of trace silicate and phosphate. Based on the principle of chemiluminescence measurement, phosphate exhibits a fast reaction speed and high luminescence intensity in the reaction with ammonium molybdate, which is significantly different from the reaction characteristics of silicate. Therefore, it is proposed to eliminate the mutual influence of the two in the chemiluminescence system by changing the reaction conditions. It is a method for rapid measurement of trace silicate and phosphate proposed by utilizing the time difference and luminescence intensity difference between phosphate and silicate in the reaction. It can simultaneously detect trace silicate and phosphate content in water. On the basis of accurately quantifying phosphate, it eliminates the measurement influence of phosphate on silicate in chemiluminescence. This method is based on chemiluminescence, solves the problem of being unable to eliminate the influence of phosphate in silicate measurement, and accurately quantifies phosphate concentration at the same time, realizing rapid measurement of silicate and phosphate in water.

[0009] The first aspect of the present invention is to provide a method for rapid measurement of trace silicate and phosphate, comprising:

[0010] S1, based on determining that the current calibration environment is a low-concentration linear calibration stage or a high-concentration nonlinear calibration stage, respectively, a corresponding linear calibration method or a nonlinear calibration method is implemented in two reaction systems and corresponding calibration data is obtained; wherein the reaction systems are respectively a first reaction system and a second reaction system, and the reaction systems are distinguished according to the high voltage value and reaction time of the chemiluminescence analyzer; and the nonlinear calibration method is implemented based on the transition probability P and the quenching parameter K;

[0011] S2, performing rapid measurement of trace silicate and phosphate based on the calibration data and the reaction system.

[0012] Preferably, the linear calibration method includes:

[0013] S11, construct the first reaction system, adjust the high voltage of the chemiluminescence instrument to V1, and adjust the reaction time to 5-10s;

[0014] S12, preparing a plurality of silicate standard liquids of different concentrations, and establishing a silicate standard curve in the first reaction system according to the plurality of silicate standard liquids of different concentrations, as shown in formula (1):

[0015] y1=k1x1+b1 (1);

[0016] wherein y1 is the silicate concentration under the first reaction system, x1 is the silicate standard solution concentration under the first reaction system, j1 is the first silicate slope, and b1 is the first silicate intercept;

[0017] S13, configuring a plurality of different concentrations of phosphate standard solution, and establishing a phosphate standard curve according to the plurality of different concentrations of phosphate standard solution under the first reaction system, as shown in formula (2):

[0018] y2=k2x2+b2 (2);

[0019] wherein y2 is the phosphate concentration under the first reaction system, x2 is the phosphate standard solution concentration under the first reaction system, k2 is the first phosphate slope, and b2 is the first phosphate intercept;

[0020] S14, constructing a second reaction system, adjusting the high pressure of the chemiluminescence instrument to V2, and adjusting the reaction time to 50-60s;

[0021] S15, configuring a plurality of different concentrations of silicate standard solution, and establishing a silicate standard curve according to the plurality of different concentrations of silicate standard solution under the second reaction system, as shown in formula (3):

[0022] y3=k3x3+b3 (3);

[0023] wherein y3 is the silicate concentration under the second reaction system, x3 is the silicate standard solution concentration under the second reaction system, k3 is the second silicate slope, and b3 is the second silicate intercept;

[0024] S16, configuring a plurality of different concentrations of phosphate standard solution, and establishing a phosphate standard curve according to the plurality of different concentrations of phosphate standard solution under the second reaction system, as shown in formula (4):

[0025] y4=k4x4+b4 (4);

[0026] wherein y4 is the phosphate concentration under the second reaction system, x4 is the phosphate standard solution concentration under the second reaction system, k4 is the second phosphate slope, and b4 is the second phosphate intercept;

[0027] S17, after the linear calibration method is completed, the chemiluminescence instrument records the calibration data and the corresponding reaction system.

[0028] Preferably, for the linear calibration method, the S2 comprises:

[0029] In the water sample measurement, the first dynamic curve peak value L1 under the first reaction system and the second dynamic curve peak value L2 under the second reaction system are measured respectively, and the first dynamic curve peak value L1 and the second dynamic curve peak value L2 are respectively represented as formula (5) and formula (6):

[0030] L1=k1C1+b1+k2C2+b2 (5);

[0031] L2=k3C1+b3+k4C2+b4 (6);

[0032] Then, the concentration calculation formula of the silicate concentration C1 and the phosphate concentration C2 of the water sample is as shown in the following formula (7) and (8):

[0033]

[0034] Preferably, the implementation steps of the nonlinear calibration method considering the energy transfer probability P and the quenching parameter K include:

[0035] S11', establishing a nonlinear calibration model; the nonlinear calibration model includes a Stern-Volmer quenching model or a model containing energy transfer;

[0036] (1) The Stern-Volmer quenching model includes:

[0037] For a single ion:

[0038] Where [Q] represents the luminescence intensity without a quencher; L is the luminescence intensity when the quencher concentration is [Q], and K SV is the Stern-Volmer quenching constant, that is, a form of the quenching parameter K;

[0039] For a two-component system, it is assumed that two ions quench each other, and the quenching effect is additive as follows:

[0040]

[0041] Where K 11 and K 22 are self-quenching constants; K 12 and K 21 are cross-quenching constants;

[0042] (2) The model containing energy transfer: the energy transfer probability P affects the coefficient in the model or introduces an additional term. If the energy is transferred from the silicate system to the phosphate system and causes the luminescence of the latter to be enhanced or sensitized, then the apparent k2 value of the phosphate depends on the concentration of the silicate, as follows:

[0043] k 2eff= k2 · (1 + P transfer · C1);

[0044] where k 2eff is the apparent k2 value for phosphate;

[0045] Alternatively, energy transfer can result in energy loss, which is equivalent to quenching.

[0046] S12', determining the non-linear function based on the non-linear calibration model through experiments and fitting: the actual modified model form f(C1, C2, P, K) is determined through a plurality of standard solution experiments covering the expected high concentration range; standard samples of different combined concentrations (C1, C2) are prepared respectively, and the luminescence intensities L'1 and L'2 are measured under two reaction systems; through non-linear regression analysis, the function that best describes the relationship between L'1 and (C1, C2) and the relationship between L'2 and (C1, C2) is fitted, which includes the quenching parameter K and the energy transfer probability P or its equivalent parameter;

[0047] S13', after completing the non-linear calibration method, the chemiluminescence instrument records all the fitted parameters, including:

[0048] k1, k2, b1, b2, P1 and K1 for the first kinetic curve peak fitting under the first reaction system and k3, k4, b3, b4, P2 and K2 for the second kinetic curve peak fitting under the second reaction system are stored in the instrument or analysis software for subsequent concentration calculation of unknown samples.

[0049] Preferably, the standard solution experiment includes:

[0050] (1) Design experiment: prepare a two-dimensional concentration grid of silicate and phosphate mixed standard solutions;

[0051] (2) Measurement: for each mixed standard sample, measure its luminescence intensities L'1 and L'2 under the first reaction system and the second reaction system respectively;

[0052] (3) Fitting of the non-linear calibration model according to the first reaction system and the second reaction system.

[0053] Preferably, the fitting of the non-linear calibration model according to the first reaction system and the second reaction system includes:

[0054] Using all (C1, C2, L'1) data points under the first reaction system, all parameters of the model function f1(C1, C2, P, K) including k1, k2, b1, b2 and P and K are fitted through non-linear regression;

[0055] using all (C1, C2, L'2) data points in the second reaction system, all parameters of the model function f2(C1, C2, P, K) are fitted by non-linear regression, including k3, k4, b3, b4, and P and K;

[0056] wherein the values of P and K are independent in f1(C1, C2, P, K) and f2(C1, C2, P, K).

[0057] Preferably, for the non-linear calibration method, the S2 comprises:

[0058] When measuring the water sample, the first kinetic curve peak value L'1 in the first reaction system and the second kinetic curve peak value L'2 in the second reaction system are measured respectively, and the first kinetic curve peak value L'1 and the second kinetic curve peak value L'2 are respectively represented as formula (5') and formula (6'):

[0059] L'1 = f1(C1, C2, P, K) (5');

[0060] L'2 = f2(C1, C2, P, K) (6');

[0061] wherein f1(C1, C2, P, K) and f2(C1, C2, P, K) are the specific forms of the actual modified model form f(C1, C2, P, K) used to replace the original linear superposition equation;

[0062] The concentrations of the silicate concentration C1 and the phosphate concentration C2 of the water sample are calculated.

[0063] Preferably, the calculation method for calculating the concentrations of the silicate concentration C1 and the phosphate concentration C2 of the water sample comprises:

[0064] (1) determining known parameters, including: measured values L'1 and L'2, known non-linear model functions f1(C1

[0065] , C2, P, K), f2(C1, C2, P, K) and their parameters k1, k2, k3, k4, b1, b2, b3, b4, P and K, and solving unknown concentrations silicate concentration C1 and phosphate concentration C2;

[0066] (2) solving the non-linear equation set composed of equations (5') and (6') based on a numerical iteration method, the numerical iteration method comprising: Newton-Raphson method or least squares optimization, wherein the least squares optimization comprises finding (C1, C2) values that minimize (L'1-L1) 2 -(L'2-L2) 2 , wherein L' 1measured and L' 2measuredrespectively the first kinetic curve peak measured value and the second kinetic curve peak measured value;

[0067] (3) using Newton-Raphson method or least square method optimized iterative algorithm to solve nonlinear equations:

[0068] L'1=f1(C1,C2,k1,k2,b1,b2,P1,K1);

[0069] L'2=f2(C1,C2,k3,k4,b3,b4,P2,K2)。

[0070] The second aspect of the application is to provide a rapid measurement system of trace silicate and phosphate, for implementing the method of the first aspect, comprising:

[0071] The calibration module (101) is used for implementing the corresponding linear calibration method or nonlinear calibration method under two reaction systems respectively based on determining that the current calibration environment is a low concentration linear calibration stage or a high concentration nonlinear calibration stage and obtaining the corresponding calibration data, wherein the reaction systems are the first reaction system and the second reaction system respectively, and the reaction systems are distinguished according to the high pressure value and the reaction time of the chemiluminescence instrument, and the nonlinear calibration method is realized based on the transfer probability P and the quenching parameter K;

[0072] The measurement module (102) is used for rapid measurement of trace silicate and phosphate based on the calibration data and the reaction system.

[0073] The third aspect of the application is to provide a rapid measurement device of trace silicate and phosphate, for implementing the method of the first aspect to measure the concentration of silicate and phosphate based on chemiluminescence method, comprising:

[0074] The sample cup (1), the heater (2), the ammonium molybdate solution storage bottle (3), the sulfuric acid storage bottle (4), the luminol light-emitting agent storage bottle (5), the light-emitting dish (6), the photomultiplier tube (7), and the data acquisition and analysis system (8); wherein the water sample enters the measuring device from the sample cup (1), is heated at constant temperature in the heater (2), and then enters the light-emitting dish (6), first, the ammonium molybdate solution in the ammonium molybdate solution storage bottle (3) and the sulfuric acid in the sulfuric acid storage bottle (4) are added to the light-emitting dish (6), and react with the silicate in the water sample to generate silicomolybdate, this process needs to be carried out for tens of seconds, after the reaction is completed, the luminol light-emitting agent in the luminol light-emitting agent storage bottle (5) is added to the light-emitting dish (6), the silicomolybdate oxidizes the luminol to generate a chemiluminescence effect, which is detected and received by the photomultiplier tube (7), and after being amplified and converted into an electric signal, is transmitted to the data acquisition and analysis system (8), the concentration of silicate and phosphate is calculated, the electric signal is characterized as a kinetic curve peak value, and the data acquisition and analysis system (8) includes a program code corresponding to the rapid measurement method of trace silicate and phosphate.

[0075] The rapid measurement method and device of trace silicate and phosphate according to the application have the following beneficial effects:

[0076] The application proposes different reaction systems suitable for silicate and phosphate and establishes a calculation method of trace silicate and phosphate, so that the influence of phosphate on the chemiluminescence silicate measurement method is eliminated; the measurement speed is fast, and the measurement is completed within 4 minutes; and no additional masking agent is needed. BRIEF DESCRIPTION OF DRAWINGS

[0077] In order to more clearly illustrate the technical solutions in the specific embodiments or related art, the drawings needed to be used in the specific embodiments or related art description will be briefly introduced below. Obviously, the drawings in the following description are some embodiments of the application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0078] Figure 1 The rapid measurement method of trace silicate and phosphate provided for the embodiments of the application is shown in the principle block diagram;

[0079] Figure 2 The rapid measurement method of trace silicate and phosphate provided for the embodiments of the application is shown in the principle block diagram;

[0080] Figure 3 The rapid measurement system of trace silicate and phosphate provided for the embodiments of the application is shown in the principle architecture diagram;

[0081] Figure 4A structure schematic diagram of the rapid measuring device for trace silicate and phosphate provided by the embodiment of the present application is shown. DETAILED DESCRIPTION

[0082] The technical solutions of the present application will be described clearly and completely below with reference to the drawings. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts fall within the scope of protection of the present application.

[0083] In the description of the present application, it should be noted that the orientations or positional relationships indicated by the terms “center”, “upper”, “lower”, “left”, “right”, “vertical”, “horizontal”, “inner”, “outer” and the like are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms “first”, “second”, “third” are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0084] In the description of the present application, it should be noted that, unless otherwise explicitly specified and limited, the terms “mounting”, “connection”, “connecting” should be understood broadly, for example, can be fixed connection, can also be detachable connection, or integrally connected; can be mechanical connection, can also be electrical connection; can be directly connected, can also be indirectly connected through an intermediate medium, can be the communication inside two elements. For those skilled in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0085] Embodiment one

[0086] As shown in the figure, the present embodiment provides a rapid measuring method for trace silicate and phosphate, comprising: Figures 1-2

[0087] S1, based on determining that the current calibration environment is a low-concentration linear calibration stage or a high-concentration nonlinear calibration stage, respectively implementing a linear calibration method or a nonlinear calibration method corresponding to two reaction systems and obtaining corresponding calibration data; wherein the reaction systems are respectively a first reaction system and a second reaction system, and the reaction systems are distinguished according to the high pressure value and the reaction time of the chemiluminescence instrument; the nonlinear calibration method is realized based on transfer probability P and quenching parameter K;

[0088] S2, based on the calibration data and the reaction system, rapidly measuring trace silicate and phosphate.

[0089] As a preferred embodiment, the linear calibration method comprises:​

[0090] S11, constructing a first reaction system, adjusting the high pressure of a chemiluminescence instrument to V1, and adjusting the reaction time to 5-10 s;

[0091] S12, configuring a plurality of different concentrations of silicate standard liquids, and establishing a silicate standard curve according to the plurality of different concentrations of silicate standard liquids under the first reaction system, as shown in formula (1):

[0092] y1=k1x1+b1 (1);

[0093] wherein y1 is the silicate concentration under the first reaction system, x1 is the silicate standard liquid concentration under the first reaction system, k1 is the first silicate slope, and b1 is the first silicate intercept;

[0094] S13, configuring a plurality of different concentrations of phosphate standard liquids, and establishing a phosphate standard curve according to the plurality of different concentrations of phosphate standard liquids under the first reaction system, as shown in formula (2):

[0095] y2=k2x2+b2 (2);

[0096] wherein y2 is the phosphate concentration under the first reaction system, x2 is the phosphate standard liquid concentration under the first reaction system, k2 is the first phosphate slope, and b2 is the first phosphate intercept;

[0097] S14, constructing a second reaction system, adjusting the high pressure of the chemiluminescence instrument to V2, and adjusting the reaction time to 50-60 s;

[0098] S15, configuring a plurality of different concentrations of silicate standard liquids, and establishing a silicate standard curve according to the plurality of different concentrations of silicate standard liquids under the second reaction system, as shown in formula (3):

[0099] y3=k3x3+b3 (3);

[0100] wherein y3 is the silicate concentration under the second reaction system, x3 is the silicate standard liquid concentration under the second reaction system, k3 is the second silicate slope, and b3 is the second silicate intercept;

[0101] S16, configuring a plurality of different concentrations of phosphate standard liquids, and establishing a phosphate standard curve according to the plurality of different concentrations of phosphate standard liquids under the second reaction system, as shown in formula (4):

[0102] y4=k4x4+b4 (4);

[0103] Wherein, y4 is the concentration of phosphate in the second reaction system, x4 is the concentration of phosphate standard solution in the second reaction system, k4 is the second phosphate slope, and b4 is the second phosphate intercept.

[0104] S17, after the linear calibration method is completed, the chemiluminescence instrument records the calibration data and the corresponding reaction system.

[0105] As a preferred embodiment, for the linear calibration method, the S2 comprises:

[0106] When measuring the water sample, the first kinetic curve peak L1 in the first reaction system and the second kinetic curve peak L2 in the second reaction system are measured respectively, and the first kinetic curve peak L1 and the second kinetic curve peak L2 are represented as formula (5) and formula (6) respectively:

[0107] L1=k1C1+b1+k2C2+b2 (5);

[0108] L2=k3C1+b3+k4C2+b4 (6);

[0109] Then the concentration calculation formula of the silicate concentration C1 and the phosphate concentration C2 of the water sample is shown in formula (7) and (8) as follows:

[0110]

[0111] In addition, the step S1 also considers the non-linear calibration. According to the chemiluminescence principle, the light intensity of a plurality of substances oxidizing luminol under certain conditions is superimposed, so this method is suitable for the measurement environment of trace silicate and phosphate. The light intensity of trace silicate and phosphate in the chemiluminescence system is linearly superimposed, and as the concentration of phosphate and silicate continuously increases, the superposition of light intensity often appears nonlinear phenomenon, and then the energy transfer probability P and the quenching coefficient K need to be considered.

[0112] As a preferred embodiment, the implementation condition of the non-linear calibration method is that the concentration of phosphate and / or silicate is too high.

[0113] Specifically, when the concentration exceeds the linear range established by the calibration curve (i.e. formula (1)-(4)) of the method, the non-linear phenomenon occurs. The reasons are as follows:

[0114] (1) The premise of ideal linear superposition (low concentration):

[0115] A. At very low concentration (trace), silicate and phosphate ions produce excited state intermediates (such as 3-amino phthalate anion excited state produced after luminol is oxidized) in the chemiluminescence reaction.

[0116] B. These excited-state molecules are far enough apart from each other that they decay independently and emit photons (luminescence).

[0117] C. The probability of collision between excited-state molecules and other molecules (solvent, solutes, oxygen, etc.) is very low.

[0118] Therefore, for the first reaction system, the total luminescence intensity L can be simply seen as a linear superposition of the luminescence intensities produced by each of the two ions:

[0119] L = L Si + L PO4 = (k1 · C1 + b1) + (k2 · C2 + b2);

[0120] It is the model on which equations (5) and (6) are based.

[0121] (2) Conditions for non-linear phenomena to occur (high concentrations):

[0122] A. When the concentration of silicate C1 and / or phosphate C2 increases significantly:

[0123] Collisional quenching: The probability of collision between excited-state molecules (luminescers) and other molecules (including the target analyte molecules themselves, other solute molecules, dissolved oxygen, etc.) increases greatly. These collisions can cause the excited-state energy to dissipate in a non-radiative manner (such as heat energy) rather than emitting photons. This is quenching.

[0124] Energy transfer: At high concentrations, the distance between excited-state molecules or between excited-state molecules and other molecules shortens. This can cause the excited-state energy to be transferred between different molecules (Energy Transfer). This transfer can ultimately result in luminescence (sensitized luminescence) or quenching (if the acceptor molecule is non-luminescent).

[0125] Other effects: High concentrations can cause changes in the microenvironment of the reaction system, such as viscosity, ionic strength, pH, etc., affecting reaction rates and luminescence efficiency; reactants can be consumed too quickly at too high a concentration, making it impossible to maintain a steady state; product accumulation can also cause interference.

[0126] B. Consequences: These effects violate the assumption of "independent luminescence, intensity linear superposition" at low concentrations. The result is:

[0127] B1. The measured total luminescence intensity L is no longer equal to (k1 · C1 + b1) + (k2 · C2 + b2);

[0128] B2. The growth rate of luminescence intensity L will be lower than expected by linear concentration growth (i.e., there is a negative deviation), and it may even reach a plateau or decline (in the case of severe quenching). This is the non-linear phenomenon.

[0129] As a preferred embodiment, the implementation steps of the nonlinear calibration method considering the energy transfer probability P and the quenching parameter K include:

[0130] S11', establishing a nonlinear calibration model; the nonlinear calibration model includes a Stern-Volmer quenching model or a model including energy transfer;

[0131] The goal of establishing a more complex nonlinear calibration model is to no longer use a simple linear model y = kx + b to fit the luminescence intensity L of a single ion at high concentrations. Si or L PO4 Instead, a nonlinear model including the quenching term K and / or the energy transfer term P is established.

[0132] (1) Stern-Volmer quenching model, including:

[0133] For a single ion:

[0134] Where [Q] represents the luminescence intensity without quencher; L is the luminescence intensity when the quencher concentration is [Q], K SV is the Stern-Volmer quenching constant, a form of the quenching parameter K;

[0135] For a two-component system, the model becomes more complicated. One possible approximation is to assume that the two ions quench each other and that the quenching effects are additive:

[0136]

[0137] Among them, K 11 and K 22 is the self-quenching constant; K 12 and K 21 is the cross quenching constant.

[0138] (2) Models involving energy transfer: The energy transfer probability P usually affects the coefficients in the model or introduces additional terms. For example, if energy is transferred from a silicate system to a phosphate system and leads to enhanced luminescence (sensitization) of the latter, then the apparent k2 value of the phosphate may depend on the silicate concentration:

[0139] k 2eff =k2·(1+P transfer C1);

[0140] Alternatively, energy transfer may result in a loss of energy (if the acceptor does not emit light), which is equivalent to a form of quenching.

[0141] S12', based on the nonlinear calibration model, a nonlinear function is determined through experiments and fitting: the actual correction model form f(C1, C2, P, K) is determined through a large number of standard solution experiments covering the expected high concentration range. Standard samples with different combined concentrations (C1, C2) need to be prepared separately, and the luminescence intensities L'1 and L'2 need to be measured in two reaction systems. Through nonlinear regression analysis, the function that best describes the relationship between L'1 and (C1, C2) and the relationship between L'2 and (C1, C2) is fitted, which includes the quenching parameter K and the energy transfer probability P or their equivalent parameters.

[0142] S13′, after completing the nonlinear calibration method, the chemiluminescence analyzer records all fitted parameters, including:

[0143] k1, k2, b1, b2, P1 and K1 used for peak fitting of the first kinetic curve under the first reaction system and k3, k4, b3, b4, P2 and K2 used for peak fitting of the second kinetic curve under the second reaction system are stored in the instrument or analysis software for subsequent concentration calculation of unknown samples.

[0144] As a preferred embodiment, the standard solution experiment includes:

[0145] (1) Experimental design: Prepare a two-dimensional concentration grid of mixed silicate and phosphate standard solutions. For example, fix several phosphate concentrations and vary the silicate concentration at each fixed phosphate concentration (from a low-concentration linear region to a high-concentration nonlinear region), and vice versa. Sufficient points are required to fully characterize the nonlinear behavior.

[0146] (2) Measurement: For each mixed standard sample, measure its luminescence intensity L'1 and L'2 in the first reaction system (high pressure V1, short reaction time 5-10s) and the second reaction system (high pressure V2, long reaction time 50-60s).

[0147] (3) fitting a nonlinear calibration model according to the first reaction system and the second reaction system, including:

[0148] Using all (C1, C2, L'1) data points under the first reaction system, all parameters of the model function f1(C1, C2, P, K), including k1, k2, b1, b2 and the newly introduced P and K, are fitted by nonlinear regression;

[0149] Using all (C1, C2, L'2) data points under the second reaction system, all parameters of the model function f2(C1, C2, P, K), including k3, k4, b3, b4 and the newly introduced P and K, were fitted by nonlinear regression;

[0150] Wherein, the quenching and energy transfer behavior in different reaction systems can be different, thus the values of P and K in f1(C1, C2, P, K) and f2(C1, C2, P, K) are independent.

[0151] As a preferred embodiment, for the nonlinear calibration method, the S2 comprises:

[0152] When measuring the water sample, the first dynamic curve peak value L'1 in the first reaction system and the second dynamic curve peak value L'2 in the second reaction system are measured respectively, and the first dynamic curve peak value L'1 and the second dynamic curve peak value L'2 are respectively represented as formula (5') and formula (6'):

[0153] L'1 = f1(C1, C2, P, K) (5');

[0154] L'2 = f2(C1, C2, P, K) (6');

[0155] Wherein, f1(C1, C2, P, K) and f2(C1, C2, P, K) are specific forms of the actual correction model form f(C1, C2, P, K), which are used to replace the original linear superposition equation;

[0156] Then the concentration calculation method of the silicate concentration C1 and the phosphate concentration C2 of the water sample comprises:

[0157] (1) Determine the known parameters, including: measured values L'1 and L'2, known nonlinear model functions f1(C1, C2, P, K), f2(C1, C2, P, K) and their parameters k1, k2, k3, k4, b1, b2, b3, b4, P and K, and solve the unknown concentrations of silicate concentration C1 and phosphate concentration C2;

[0158] (2) Solve the nonlinear equation set composed of equations (5') and (6') based on a numerical iteration method, wherein the numerical iteration method comprises: Newton-Raphson method or least squares optimization, wherein the least squares optimization comprises finding (C1, C2) values that can minimize (L'1-L1) 2 -(L'2-L2) 2 , wherein L' 1measured and L' 2measured are the measured values of the first dynamic curve peak value and the second dynamic curve peak value respectively.

[0159] In this embodiment, the process is usually accomplished by computer program or instrument built-in software. User inputs measured L'1 and L'2, software runs iterative algorithm using pre-stored calibration parameters (including k1, k2, k3, k4, b1, b2, b3, b4, P and K) and defined non-linear model functions f1(C1, C2, P, K) and f2(C1, C2, P, K), and finally outputs calculated C1 and C2.

[0160] (3) Solve non-linear equations using Newton method or iterative algorithm of least square optimization:

[0161] L'1 = f1(C1, C2, k1, k2, b1, b2, P1, K1);

[0162] L'2 = f2(C1, C2, k3, k4, b3, b4, P2, K2).

[0163] The introduction of non-linear model in this embodiment has the following characteristics:

[0164] (1) Complexity: The introduction of P and K to handle non-linearity significantly increases the complexity of the method. Calibration requires more standard solutions and more complex fitting process, and concentration calculation requires numerical iteration rather than simple formula.

[0165] (2) Model selection: In practical application, appropriate non-linear model (such as Stern-Volmer or its variants) needs to be selected by experiment according to specific chemiluminescence system (reagents, pH, interference, etc.), and P and K are key physicochemical parameters in these models.

[0166] (3) Applicability: This non-linear correction is mainly used to handle samples with concentrations beyond the linear range. For samples with concentrations within the linear range, it is simpler and faster to use the original linear model and formulas (5) and (6) for calculation.

[0167] (4) Actual operation: Modern chemiluminescence instruments usually have these complex calibration and calculation processes built into their software if they claim to support high concentration or non-linear correction. The main task of the user is to perform more comprehensive calibration (prepare enough high concentration mixed standards) according to the instrument requirements, and the subsequent calculation is automatically completed by the instrument software.

[0168] In short, when the concentration of silicate or phosphate is too high to cause the superposition of luminescence intensity to be no longer linear, a non-linear calibration model (f1, f2) containing quenching (K) and energy transfer (P) effects needs to be established through experiment, and numerical methods are used to solve these non-linear equations to obtain the concentration (C1, C2) when measuring unknown samples. This is much more complex than the linear method at low concentration.

[0169] Example Two

[0170] As Figure 3 The embodiment provides a rapid measurement system of trace silicate and phosphate, which is used for implementing the method of the first embodiment and comprises the following steps:

[0171] The calibration module 101 is configured to implement a linear calibration method or a nonlinear calibration method in two reaction systems according to a current calibration environment, and obtain corresponding calibration data, wherein the reaction systems are a first reaction system and a second reaction system, and the reaction systems are distinguished according to a high-pressure value and a reaction time of the chemiluminescence instrument; and the nonlinear calibration method is based on a transfer probability P and a quenching parameter K.

[0172] The measurement module 102 is configured to perform rapid measurement of trace silicate and phosphate based on the calibration data and the reaction system.

[0173] Embodiment three

[0174] As Figure 4 The embodiment provides a rapid measurement device of trace silicate and phosphate, which is used for implementing the method of the first aspect to measure the concentration of silicate and phosphate based on the chemiluminescence method, and comprises the following steps:

[0175] The sample cup 1, the heater 2, the ammonium molybdate solution storage bottle 3, the sulfuric acid storage bottle 4, the luminol lightening agent storage bottle 5, the lightening dish 6, the photomultiplier tube 7 and the data acquisition and analysis system 8; wherein the water sample enters the measurement device from the sample cup 1, is heated at constant temperature in the heater 2 and then enters the lightening dish 6, ammonium molybdate solution in the ammonium molybdate solution storage bottle 3 and sulfuric acid in the sulfuric acid storage bottle 4 are first added to the lightening dish 6, react with silicate in the water sample to generate silicomolybdate heteropoly acid, and the process needs to be performed for tens of seconds, after the reaction is completed, the luminol lightening agent in the luminol lightening agent storage bottle 5 is added to the lightening dish 6, the silicomolybdate heteropoly acid oxidizes the luminol to generate a chemiluminescence effect, which is detected and received by the photomultiplier tube 7, is amplified and converted into an electric signal and then transmitted to the data acquisition and analysis system 8, and the concentration of silicate and phosphate is calculated, the electric signal is characterized by a kinetic curve peak value, and the data acquisition and analysis system 8 comprises program code corresponding to the rapid measurement method of trace silicate and phosphate.

[0176] Those skilled in the art can clearly understand the above-mentioned embodiments from the description of the above embodiments that the above-mentioned embodiments can be realized by software, or can be realized by software and necessary general hardware platform. Based on such understanding, the technical solutions of the above-mentioned embodiments can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (which can be CD-ROM, U disk, mobile hard disk, etc.), including a plurality of instructions for making a computer device (which can be a personal computer, a server, or a network device, etc.) execute the methods described in various embodiments of the present application.

[0177] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for rapid measurement of trace silicate and phosphate, characterized in that: include: S1, based on determining that the current calibration environment is a low-concentration linear calibration stage or a high-concentration nonlinear calibration stage, respectively, a corresponding linear calibration method or a nonlinear calibration method is implemented in two reaction systems and corresponding calibration data is obtained; wherein the reaction systems are respectively a first reaction system and a second reaction system, and the reaction systems are distinguished according to the high voltage value and reaction time of the chemiluminescence analyzer; and the nonlinear calibration method is implemented based on the transition probability P and the quenching parameter K; S2, performing rapid measurement of trace silicate and phosphate based on the calibration data and the reaction system.

2. The method for rapid measurement of trace silicate and phosphate according to claim 1, characterized in that: The linear calibration method comprises: S11, construct the first reaction system, adjust the high voltage of the chemiluminescence instrument to V1, and adjust the reaction time to 5-10s; S12, preparing a plurality of silicate standard liquids of different concentrations, and establishing a silicate standard curve in the first reaction system according to the plurality of silicate standard liquids of different concentrations, as shown in formula (1): y1=k1x1+b1 (1); Wherein, y1 is the silicate concentration under the first reaction system, x1 is the silicate standard liquid concentration under the first reaction system, k1 is the first silicate slope, and b1 is the first silicate intercept; S13, preparing a plurality of phosphate standard liquids of different concentrations, and establishing a phosphate standard curve in the first reaction system according to the plurality of phosphate standard liquids of different concentrations, as shown in formula (2): y2=k2x2+b2 (2); Wherein, y2 is the phosphate concentration under the first reaction system, x2 is the phosphate standard liquid concentration under the first reaction system, k2 is the first phosphate slope, and b2 is the first phosphate intercept; S14, constructing a second reaction system, adjusting the high voltage of the chemiluminescence instrument to V2, and adjusting the reaction time to 50-60 s; S15, preparing a plurality of silicate standard liquids of different concentrations, and establishing a silicate standard curve in the second reaction system according to the plurality of silicate standard liquids of different concentrations, as shown in formula (3): y3=k3x3+b3 (3); Wherein, y3 is the silicate concentration in the second reaction system, x3 is the silicate standard liquid concentration in the second reaction system, k3 is the second silicate slope, and b3 is the second silicate intercept; S16, preparing a plurality of phosphate standard liquids of different concentrations, and establishing a phosphate standard curve in the second reaction system according to the plurality of phosphate standard liquids of different concentrations, as shown in formula (4): y4=k4x4+b4 (4); Wherein, y4 is the phosphate concentration in the second reaction system, x4 is the phosphate standard liquid concentration in the second reaction system, k4 is the second phosphate slope, and b4 is the second phosphate intercept; S17, after completing the linear calibration method, the chemiluminescence instrument records the calibration data and the corresponding reaction system.

3. A rapid measurement method for trace silicate and phosphate according to claim 2, characterized in that: For the linear calibration method, S2 includes: When measuring water samples, the first kinetic curve peak value L1 under the first reaction system and the second kinetic curve peak value L2 under the second reaction system are measured respectively. The first kinetic curve peak value L1 and the second kinetic curve peak value L2 are expressed as formula (5) and formula (6) respectively: L1=k1C1+b1+k2C2+b2 (5); L2=k3C1+b3+k4C2+b4 (6); The calculation formulas for the silicate concentration C1 and the phosphate concentration C2 of the water sample are as shown in the following equations (7) and (8):

4. The method for rapid measurement of trace silicate and phosphate according to claim 3, characterized in that: The implementation steps of the nonlinear calibration method considering the energy transfer probability P and the quenching parameter K include: S11', establishing a nonlinear calibration model; the nonlinear calibration model includes a Stern-Volmer quenching model or a model including energy transfer; (1) Stern-Volmer quenching model, including: For a single ion: Where [Q] represents the luminescence intensity without quencher; L is the luminescence intensity when the quencher concentration is [Q], K SV is the Stern-Volmer quenching constant, a form of the quenching parameter K; For a two-component system, it is assumed that the two ions quench each other and that the quenching effects can be added together as follows: Among them, K 11 and K 22 is the self-quenching constant; K 12 and K 21 is the cross-quenching constant; (2) Models involving energy transfer: The energy transfer probability P affects the coefficients in the model or introduces additional terms. If energy is transferred from the silicate system to the phosphate system and causes the latter to enhance or sensitize the luminescence, then the apparent k2 value of the phosphate depends on the silicate concentration, as shown below: k 2eff =k2·(1+P transfer ·C1); where k 2eff is the apparent k2 value of phosphate; Alternatively, energy transfer may result in energy loss, which is equivalent to a form of quenching; S12', based on the nonlinear calibration model, a nonlinear function is determined by experiments and fitting: the actual correction model form f(C1, C2, P, K) is determined by experiments with multiple standard solutions covering the expected high concentration range; standard samples with different combined concentrations (c1, C2) are prepared respectively, and the luminescence intensities L'1 and L'2 are measured in two reaction systems; through nonlinear regression analysis, a function that best describes the relationship between L'1 and (C1, C2) and the relationship between L'2 and (C1, C2) is fitted, which includes the quenching parameter K and the energy transfer probability P or their equivalent parameters; S13′, after completing the nonlinear calibration method, the chemiluminescence analyzer records all fitted parameters, including: k1, k2, b1, b2, P1 and K1 used for peak fitting of the first kinetic curve under the first reaction system and k3, k4, b3, b4, P2 and K2 used for peak fitting of the second kinetic curve under the second reaction system are stored in the instrument or analysis software for subsequent concentration calculation of unknown samples.

5. A rapid measurement method for trace silicate and phosphate according to claim 4, characterized in that: The standard solution experiment includes: (1) Experimental design: Prepare a two-dimensional concentration grid of mixed silicate and phosphate standard solutions; (2) performing measurements: for each mixed standard sample, measuring its luminescence intensity L'1 and L'2 in the first reaction system and the second reaction system, respectively; (3) Fitting a nonlinear calibration model according to the first reaction system and the second reaction system.

6. A method for rapid measurement of trace silicate and phosphate according to claim 5, characterized in that: The fitting of the nonlinear calibration model according to the first reaction system and the second reaction system includes: Using all (C1, C2, L ' 1) For each data point, use nonlinear regression to fit all parameters of the model function f1(C1, C2, P, K), including k1, k2, b1, b2, P, and K; Using all (C1, C2, L ' 2) For each data point, all parameters of the model function f2(C1, C2, P, K) are fitted through nonlinear regression, including k3, k4, b3, b4, P and K; Among them, the values ​​of P and K are independent in f1(C1, C2, P, K) and f2(C1, C2, P, K).

7. A rapid measurement method for trace silicate and phosphate according to claim 6, characterized in that: For the nonlinear calibration method, S2 includes: When measuring water samples, the first kinetic curve peak value L'1 under the first reaction system and the second kinetic curve peak value L'2 under the second reaction system are measured respectively. The first kinetic curve peak value L'1 and the second kinetic curve peak value L'2 are expressed as formula (5') and formula (6') respectively: L'1=f1(C1,C2,P,K)(5'); L'2=f2(C1, C2, P, K) (6'); Among them, f1(C1, C2, P, K) and f2(C1, C2, P, K) are the specific forms of the actual modified model form f(C1, C2, P, K), which are used to replace the original linear superposition equation; The concentrations of the silicate concentration C1 and the phosphate concentration C2 of the water sample are calculated.

8. The method for rapid measurement of trace silicate and phosphate according to claim 7, characterized in that: The method for calculating the silicate concentration C1 and the phosphate concentration C2 of the water sample includes: (1) Determine the known parameters, including the measured values ​​L'1 and L'2, the known nonlinear model functions f1(C1, C2, P, K), f2(C1, C2, P, K) and their parameters k1, k2, k3, k4, b1, b2, b3, b4, P and K, and solve for the unknown concentrations of silicate concentration C1 and phosphate concentration C2; (2) Solving the nonlinear equations consisting of equations (5') and (6') based on a numerical iteration method, wherein the numerical iteration method includes: Newton-Raphson method or least squares optimization, wherein the least squares optimization includes finding a solution that makes (L ' 1-L1) 2 -(L ' 2-L2) 2 Minimize the (C1, C2) value, where L ' 1measured and L ' 2measured are the measured values ​​of the peak value of the first kinetic curve and the measured values ​​of the peak value of the second kinetic curve, respectively; (3) Solve the nonlinear system of equations using an iterative algorithm optimized by the Newton-Raphson method or the least squares method: L'1=f1(C1, C2, k1, k2, b1, b2, P1, K1); L'2=f2(C1, C2, k3, k4, b3, b4, P2, L2).

9. A rapid measurement system for trace silicate and phosphate, used for implementing the method according to any one of claims 1 to 8, characterized in that: include: A calibration module (101) is used to implement corresponding linear calibration methods or nonlinear calibration methods under two reaction systems based on determining whether the current calibration environment is a low-concentration linear calibration stage or a high-concentration nonlinear calibration stage, and obtain corresponding calibration data; wherein the reaction systems are respectively a first reaction system and a second reaction system, and the reaction systems are distinguished according to the high voltage value and reaction time of the chemiluminescence instrument; the nonlinear calibration method is implemented based on the transition probability P and the quenching parameter K; The measurement module (102) is used for quickly measuring trace silicate and phosphate based on the calibration data and the reaction system.

10. A rapid measurement device for trace silicate and phosphate, used for measuring the concentration of silicate and phosphate based on chemiluminescence, characterized in that: include: A sampling cup (1), a heater (2), an ammonium molybdate solution holding bottle (3), a sulfuric acid holding bottle (4), a luminol luminescent agent holding bottle (5), a luminescent dish (6), a photomultiplier tube (7), and a data acquisition and analysis system (8); wherein the water sample enters the measuring device from the sampling cup (1), is heated at a constant temperature in the heater (2), and then enters the luminescent dish (6); first, the ammonium molybdate solution in the ammonium molybdate solution holding bottle (3) and the sulfuric acid in the sulfuric acid holding bottle (4) are added to the luminescent dish (6), and react with the silicate in the water sample to generate silicomolybdic heteropoly acid. This process The reaction takes several tens of seconds. After the reaction is completed, the luminol luminescent agent in the luminol luminescent agent bottle (5) is added to the luminescent dish (6). The luminol is oxidized by the molybdenum silicoacid to produce a chemiluminescence effect, which is detected and received by the photomultiplier tube (7). After amplification and conversion into an electrical signal, it is transmitted to the data acquisition and analysis system (8). The concentrations of silicate and phosphate are calculated. The electrical signal is characterized by the peak value of the kinetic curve. The data acquisition and analysis system (8) includes a program code corresponding to the rapid measurement method of trace silicate and phosphate according to any one of claims 1 to 8.

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