178 results about "Peak area" patented technology

The invention relates to the technical field of high performance liquid chromatography detection, in particular to a liquid chromatography determination method and equipment for the content of m-tert-butylphenol, and the method comprises the following steps: determining a to-be-determined mixed solution of the prepared m-tert-butylphenol by using high performance liquid chromatography to obtain chromatographic data; the method comprises the following steps: preparing chromatographic data of standard control group solution samples of m-tert-butylphenol under different concentrations under two preset different wavelengths, and obtaining a nonlinear fitting relationship between the concentrations of m-tert-butylphenol and chromatographic peak areas; analyzing the chromatographic data deviation of the to-be-measured mixed solution, and obtaining the chromatographic peak area of the to-be-measured mixed solution after correction of the intermediate tert-butylphenol; and acquiring the concentration of the intermediate tert-butylphenol in the mixed solution to be measured corresponding to the corrected chromatographic peak area by utilizing a nonlinear fitting relationship. The invention aims to improve the measurement accuracy of the prepared m-tert-butylphenol.

The invention belongs to the technical field of medicine detection, and particularly relates to an HPLC (High Performance Liquid Chromatography) method for simultaneously qualitatively and quantitatively detecting LXH-2103 and impurities thereof. Preparing a test solution, an impurity reference solution and a contrast solution, respectively injecting the blank solution, the test solution, the impurity reference solution and the contrast solution into a liquid chromatograph, recording chromatograms, and calculating according to a peak area normalization method to obtain the content of LXH-2103 in the test solution. And calculating the content of impurities in the test solution according to a peak area by an external standard method. Wherein the impurity is one or more of LXH-ZZ1, LXH-ZZ2, LXH-ZZ3, LXH-ZZ4 and LXH-ZZ5, and the impurity is one or more of LXH-ZZ2, LXH-ZZ3, LXH-ZZ4 and LXH-ZZ5. The separation degree between the main peak and each impurity peak is good, the precision is high, the stability is good, the reproducibility is good, and an analysis means is provided for quality control of the LXH-2103.

The invention relates to an overlapped chromatographic peak positioning and splitting method and system based on a numerical stable function. The method comprises the following steps: de-noising chromatographic data and correcting a baseline; calculating a second derivative by using SG filtering, grouping continuous points according to a negative threshold value, and determining an initial position of each peak by using a second-order minimum value; establishing a peak function of bidirectional exponential correction by taking a peak position as an initial value, setting parameters and boundaries such as area, center, width, trailing and the like, constructing a residual error minimization target, and performing robust fitting by adopting a trust region reflection algorithm; and indexes such as suitability, output peak area, center, broadening, separation degree, theoretical plate number and the like are verified by residual errors. According to the method, valley point or prior component information is not needed, the method is insensitive to noise and baseline drift, serious overlapping and trailing / leading edge peaks of multiple components can be effectively processed, convergence is high, the method is insensitive to initial values, parameters can be expanded to different peak shapes, and the method is suitable for qualitative and quantitative analysis of automatic and high-flux chromatographic data.

The invention discloses a detection method of a tert-butyl-(S)-[2-(2-cyano-4, 4-difluoropyrrolidine-1-yl)-2-oxyethyl] carbamate optical isomer, which adopts a high performance liquid chromatography determination method, and the determination method comprises the following steps: adopting a chromatographic column taking amylose-tri (3, 5-dimethylphenyl carbamate) as a filler, and performing gradient elution on the obtained product, thereby obtaining the tert-butyl-(S)-[2-(2-cyano-4, 4-difluoropyrrolidine-1-yl)-2-oxyethyl] carbamate optical isomer. N-hexane-ethanol-trifluoroacetic acid with the volume ratio of (700-750): (250-300): 1 is used as a mobile phase, and after a solution is prepared for sample introduction, the content of the optical isomers is calculated according to a peak area normalization method. The invention makes up the technical blank of lack of high performance liquid chromatography detection of the substance at present.

The invention relates to the field of water quality monitoring of a secondary loop of a nuclear power plant, in particular to a synchronous detection system and method for ammonia and hydrazine. The method comprises the following steps: removing impurities in a sample by utilizing filtration and reverse chromatography; the sample is quantified to 240-260 [mu] L; carrying out gradient elution on the sample by using a methanesulfonic acid solution as an eluent; wherein in the first stage, the concentration of a methanesulfonic acid solution is controlled to be 13-18 mmol / L, and a sample is washed; in the second stage, the concentration of the methanesulfonic acid solution is controlled to be 55-70 mmol / L, and the sample is Drawing a low-concentration curve based on the 10-500 [mu] g / L standard solution, and drawing a high-concentration curve based on the 500-3000 [mu] g / L standard solution; and measuring the ionic conductivity values of NH4 < + > and N2H5 < + >, automatically selecting a corresponding concentration curve according to the peak area of the ionic conductivity values, and calculating the concentration of ammonia and hydrazine. According to the invention, the synchronous detection of ammonia and hydrazine concentration is realized, the analysis process is simplified, the use of toxic and harmful substance phenol and the generation of toxic and harmful waste liquid of yellow azo compound are solved, the measurement accuracy is improved, and the relative measurement error can be controlled within + / -2.0%.

The invention discloses a screening method and application of a positive electrode material, and belongs to the technical field of battery material screening. The screening method comprises the steps that the volume density distribution of the mixed positive electrode material to be screened is measured, Gauss fitting is conducted on distribution data, a fitted curve of bimodal distribution is screened, the center value of a first peak corresponding to small particles in double peaks is r1, the half-peak width is w1, and the peak area is A1; the central value of a second peak corresponding to large particles in the double peaks is r2, the half-peak width is w2, and the peak area is A2; a is more than or equal to 0.22474 and less than or equal to 0.7321, b is more than or equal to 0.1 and less than or equal to 2, and c is more than or equal to 0.05 and less than or equal to 7; wherein a = r1 / r2, b = w1 / w2, and c = A1 / A2. The mixed positive electrode material screened by the method is beneficial to improving the pore structure, the conductivity and the electrochemical performance of a pole piece, so that the overall performance, especially the energy density, the compactness and the power performance, of the battery is improved.

The invention discloses a compound analysis method and device for chromatographic peaks, which define an optimal chromatographic peak region according to a plurality of chromatographic peak regions, corresponding detection precision weights and core parameter types corresponding to fluid to be detected, ensure the precision of the optimal chromatographic peak region and further process the optimal chromatographic peak region. Further, defining an analytic route map according to the region matching coefficient, the type of the fluid to be detected and the peak value range of the optimal chromatographic peak region; defining a plurality of analysis nodes according to the analysis route map and the to-be-detected fluid, and triggering the composite analysis of the chromatographic peak based on the plurality of analysis nodes, the corresponding analysis content, the flow state of the to-be-detected fluid and the optimal chromatographic peak area, multiple interaction is performed on the multiple analysis nodes, the corresponding analysis content, the flowing state of the to-be-detected fluid and the optimal chromatographic peak area, and the composite analysis of the chromatographic peak is triggered, so that the accurate control of the composite analysis of the chromatographic peak is realized.

The invention discloses a preparation process of a Qingjin phlegm-reducing decoction material standard, an HPLC content determination method and a fingerprint spectrum establishment method aiming at the material standard, under the content determination method, the peak shapes of chromatographic peaks of all components are symmetrical, the separation effect is remarkable, and excellent stability, specificity, linear response, repeatability, precision and accuracy are shown. According to the present invention, the fingerprint characteristics are accurately recorded, the reversed-phase high performance liquid chromatography technology is adopted to successfully obtain 13 common peaks, the baicalin is adopted as the reference peak, the relative retention time and the relative peak area of the common peaks are calculated, and the reference substance comparison is further performed to identify the 8 common peaks; the established fingerprint spectrum method also has the characteristics of good chromatographic peak shape, high separation degree, stable method, excellent repeatability, high precision and the like. In conclusion, the invention provides a set of comprehensive and reliable Qingjin phlegm-reducing decoction material standard quality control reference system, and a scientific basis is provided for the overall quality evaluation of the Qingjin phlegm-reducing decoction.

The invention discloses a radioactive liquid activity detection method, device and equipment, and relates to the field of nuclear energy. The method comprises the following steps: acquiring a to-be-detected water sample, and respectively inputting the to-be-detected water sample into a detector to obtain a detector original pulse signal and a detector fast signal corresponding to the to-be-detected water sample; performing FPGA time window coincidence processing based on the detector original pulse signal and the detector fast signal to obtain a new energy spectrum corresponding to the to-be-detected water sample; obtaining a preprocessed theoretical energy spectrum template, and inputting the theoretical energy spectrum template and the new energy spectrum into the peak decomposition network model to obtain a characteristic peak area list of the target nuclide; and obtaining an efficiency curve of the detector, and obtaining an activity detection result of the target nuclear element in the to-be-detected water sample based on the characteristic peak area list of the target nuclide and the efficiency curve. According to the method, the final result is determined by combining the theoretical energy spectrum template, the original pulse signal of the detector and the fast signal of the detector, so that the spectrum unfolding error of the overlapping peak can be reduced, and the recognition accuracy of the mixed system is effectively improved.

The invention discloses a gas chromatography detection optimization method and device of a transformer, terminal equipment and a storage medium. The method comprises the following steps: acquiring gas chromatography original data; carrying out filtering and noise reduction according to the gas chromatography original data to obtain a gas chromatography data sequence; judging whether the peak width of the gas chromatography data sequence is smaller than a preset peak width threshold value or not according to the gas chromatography data sequence; under the condition that the peak width is smaller than or equal to a preset peak width threshold value, taking the chromatographic peak height of the gas chromatography data sequence as a gas chromatography detection result; under the condition that the peak width is greater than a preset peak width threshold value, judging whether the ratio of the peak width to the peak width of the gas chromatography data sequence is smaller than a preset height-width ratio threshold value or not; if yes, taking the chromatographic peak height as a gas chromatography detection result; and if not, calculating the peak area of the gas chromatography data sequence according to the gas chromatography data sequence, and taking the peak area as a gas chromatography detection result. By implementing the method, the accuracy of a gas chromatography detection result is improved.

The embodiment of the invention discloses a method and device for testing foam seepage characteristics of a heterogeneous porous medium, electronic equipment and a storage medium, and relates to the technical field of fluid mechanics and nuclear magnetic resonance. The method comprises the steps that a heterogeneous porous medium sample with a clear permeability level difference is prepared, and the permeability level difference of the heterogeneous porous medium sample is determined; setting test parameters according to the permeability level difference of the sample, calibrating imaging parameters of the low-field nuclear magnetic resonance equipment, and setting a weighting mode; performing foam flooding treatment on the sample according to the set injection parameters, acquiring a spectrum of the sample according to the test parameters when foam is injected into a set amount, and acquiring nuclear magnetic imaging of the sample through low-field nuclear magnetic resonance equipment according to imaging parameters and a weighting mode; according to the relaxation characteristic of the spectrum, the main peak endpoint value is used for dividing the pore channel, the foam sweep degree is calculated according to the spectrum peak area of the spectrum, and the foam plugging strength is calculated according to the signal amplitude of nuclear magnetic imaging. According to the method, the problems of poor visualization adaptability and lack of evaluation systems in the prior art are solved.

To provide a photosensitive resin composition and light-shielding film that achieve both high light-shielding properties and reduced reflectivity on both the glass substrate side and the film side, while also being environmentally friendly by using extremely low amounts of fluorine and meeting requirements such as PFAS regulations. [Solution] A photosensitive resin composition characterized by containing components (A) to (F) and satisfying both (i) and (ii) below. (i) When a cured film of the composition is deposited on a glass substrate with an average film thickness in the range of 0.5 to 4.0 μm, and the surface of the film is measured by XPS, the peak area A of SiO2 in the peak fit analysis of the Si2p3 / 2 peak is... SiO2 And, peak area A SiO The ratio (A SiO2 / A SiO The value must be between 0.10 and 10.0. (ii) The ratio of the amount of element F to the total amount of elements Si, C, O, and F present on the surface of the film [F / (Si+C+O+F)] is 5.0% or less.

The invention relates to an underwater gamma-ray energy spectrum repeatability analysis method and device and a storage medium. The method comprises the following steps: acquiring a gamma-ray energy spectrum group measured underwater; performing spectrum unfolding on the gamma-ray energy spectrum group based on a Gold iterative deconvolution spectrum unfolding algorithm to obtain energy of gamma incident rays; solving a peak value and a peak area of the gamma-ray energy spectrum group by adopting a gravity center method; determining a first relative standard deviation corresponding to the peak value and a second relative standard deviation corresponding to the peak area; and determining the repeatability of the gamma-ray spectrum group based on the first relative standard deviation and the second relative standard deviation. According to the method, the background is deducted in a spectrum unfolding mode on the basis of the Gold iteration deconvolution spectrum unfolding algorithm, then the peak value and the peak area are calculated, the background deduction error is reduced, the repeatability is improved, meanwhile, the Gold iteration deconvolution spectrum unfolding algorithm reduces the measurement time, and the measurement accuracy is improved. Therefore, the technical effects of reducing the error of background deduction and improving the repeatability based on the Gold iteration deconvolution spectrum unfolding algorithm are realized.

The invention discloses a gas chromatography method for determining the purity of methylsulfonyl fluoride. The gas chromatography method comprises the following steps: preparing a standard working solution and a test solution; respectively testing the standard working solution and the test solution by adopting a gas chromatographic method to obtain a standard working solution measurement result and a test solution measurement result; performing standard curve fitting on the measurement result of the standard working solution to obtain the function relationship between the methylsulfonyl fluoride mass and the methylsulfonyl fluoride peak area and the function relationship between the solvent mass and the solvent peak area; and calculating the purity of the methylsulfonyl fluoride in the test solution according to the test result of the test solution and the function relationship. The method is easy to operate, high in accuracy and good in stability, the chromatographic purity of the methylsulfonyl fluoride can be accurately measured, and the defect of a methylsulfonyl fluoride analysis technology is overcome.

The invention discloses a method for determining the solution concentration in the crystallization process of 3, 4-dinitrofurazan furoxan oxide, and relates to the technical field of energetic crystal materials. According to the method, an EasySampler and HPLC (High Performance Liquid Chromatography) combined method is utilized, the solubility of DNTF is measured, a standard curve of DNTF solution concentration and peak area is established by utilizing a high performance liquid chromatograph, then the EasySampler is utilized to sample a crystallization process and perform HPLC analysis, and then the solution concentration at each moment is calculated by utilizing an equation of the standard curve. According to the method, EasySampler equal interval sampling is combined with off-line HPLC (High Performance Liquid Chromatography) analysis, and a curve that the concentration of the main component of the solution changes along with the temperature is constructed. In the dominant period of crystal growth, the concentration change rate and the solid-liquid interface area are in an approximately linear relationship. The experimental data provides a necessary demonstration basis for subsequent improvement of a non-ideal system crystallization kinetics theory.

The invention discloses a Toci full-spectrum anion truth value monitoring method, system, equipment and medium, and relates to the technical field of chemical analysis. The method comprises the following steps: acquiring a response signal in a target water sample, drawing a background response peak and a target response peak by taking time as an abscissa axis and the response signal as a ordinate axis, acquiring a peak shape parameter of the background response peak, calculating a difference value between the peak shape parameter and a preset reference peak shape parameter, converting the difference value into a feature correction instruction, and correcting the feature correction instruction according to the difference value. The first peak area of the real response peak is calculated; the initial concentration of target anions is obtained according to the first peak area; the background concentration of background anions is obtained; the concentration adjustment coefficient is calculated according to the background concentration; the target concentration of the target anions is obtained. By implementing the technical scheme provided by the invention, the effect of improving the accuracy of monitoring the target anions is achieved.

Disclosed is a grain-oriented electrical steel sheet in which an insulating coating film does not contain a chromium compound but contains a phosphate. When Gaussian fitting is performed on a 31P-NMR spectrum obtained by measuring the insulating coating film by using a nuclear magnetic resonance method in the range of 16 ppm to - 90 ppm, the ratio of the peak area of the Q1 structure to the total peak area is more than 3% but not more than 18%, and the ratio of the Q1 structure is smaller than the ratio of the Q3 structure.

The present invention discloses a method for analyzing the odor contribution by measuring the relative threshold of the odor of a substance based on gas chromatography-olfactometer-mass spectrometry (GC-O-MS), and belongs to the technical field of odor evaluation. The above method comprises: first determining a reference standard substance and drawing a standard curve; determining the peak area of ​​the olfactory end threshold point of the reference standard substance by GC-O-MS, obtaining the peak area of ​​the olfactory end threshold point of the gas sample to be tested and analyzed under the same test conditions, and then calculating the relative odor threshold of the gas, establishing a relative threshold database, and being able to analyze the odor contribution of each component without the need for an odorist to smell or the use of GC-O-MS equipment. The application of the method of the present invention can greatly improve the efficiency of odor evaluation tests, reduce test costs, and reduce the degree of dependence of odor evaluation on odorists.

The invention discloses a high-flux mixed solution quality control method based on relative response factors. According to the method, by introducing an internal standard reference substance and calculating a relative response factor Rr of each target analyte relative to the internal standard, synchronous and rapid calculation and stability dynamic evaluation of all component concentrations in a solution are realized, and the method comprises the following steps: selecting and preparing an internal standard solution; analyzing the mixed solution and the internal standard under the same condition to obtain a chromatographic peak area; calculating Rr; monitoring the change of Rr along with time to judge the component stability; and calculating the current concentration of each component based on the stable Rr value and the interior label information. According to the method, only one or a small number of internal standards are needed to replace a single standard prepared for each component in a traditional method, consumption (about 90%) and workload of standard substances are remarkably reduced, unstable components can be sensitively recognized, and an efficient, economical and reliable quality control solution is provided for high-throughput detection in the fields of environmental monitoring, food safety and the like.

Provided is an electrophotographic photosensitive member that suppresses an image defect resulting from its support and is reduced in long-term potential fluctuation. The electrophotographic photosensitive member is an electrophotographic photosensitive member including a support having a cylindrical shape and a photosensitive layer formed on the support, wherein the support has a surface formed of Al and / or an Al alloy, and wherein the IR peak area ratio A of the surface of the support determined by Fourier transform infrared spectroscopy satisfies the following condition: A≥0.50 where the IR peak area ratio A represents a ratio a / z of a peak area “a” in the range of from 1,016 cm−1 or more to 1,130 cm−1 or less to a peak area “z” in the range of from 650 cm−1 or more to 1,130 cm−1 or less.

The invention relates to the technical field of analysis and detection, and discloses a method for detecting the content of nonyl phenol in a sealant, and the method comprises the following steps: carrying out derivatization treatment I on a sealant to-be-detected sample with the mass of m g, and diluting to a constant volume I to V ml to obtain a mixed solution; performing chromatographic analysis I on the mixed solution to obtain a peak area Ai of a chromatographic peak of the nonyl phenol derivative; the chromatographic analysis adopts a programmed heating mode, and the programmed heating mode comprises the following steps: preserving heat at the temperature T1 for 0.5-1.5 minutes, then heating to the temperature T2 at the rate of 20-40 DEG C / min, and preserving heat at the temperature T2 for 3-6 minutes; and calculating the mass content X of nonyl phenol in the to-be-detected sample of the sealant according to the following formula: X = (Ai-b) / k * V * F / m * 100%, wherein k is greater than or equal to 90.0 and less than or equal to 110.0; 500 < = b < = 1500. The method provided by the invention is low in cost, high in accuracy, excellent in recovery rate and high in sensitivity.

The invention relates to a method for measuring the concentration of tetrachloroethylene in water, which comprises the following steps: (1) detecting a standard working solution of tetrachloroethylene by using a high performance liquid chromatograph to obtain a standard working curve of the tetrachloroethylene absorption peak area and absolute concentration of the standard working solution of tetrachloroethylene; (2) detecting a water sample to be detected by using the high performance liquid chromatograph to obtain the tetrachloroethylene absorption peak area of the water sample to be detected; a mobile phase used in the detection of the high performance liquid chromatograph comprises an organic phase and ultrapure water, and the volume ratio of the organic phase to the ultrapure water is (70-90): (30-10); the detection wavelength of the detection is 212 to 216 nm; the temperature of a column oven of the high performance liquid chromatograph is 35-40 DEG C. According to the method disclosed by the invention, the peak appearance time is short, the separation effect of the detected main peak and the impurity peak is good, the fitting degree of the obtained standard working curve is high, the separation degree of the main peak and the impurity peak in the detection of an actual water sample containing tetrachloroethylene is high, and the detection result is reliable.

Provided in the present application is a method for measuring the residual amount of a target volatile substance. The method comprises: providing a sample under test, which sample contains a target volatile substance; providing a first closed system, which involves: placing said sample in a closed container, and making the target volatile substance reach a distribution equilibrium state in the closed container under a preset condition, so as to obtain the first closed system, wherein the distribution equilibrium state represents that the target volatile substance reaches distribution equilibrium between said sample and a gas-phase component in the closed container; and performing gas chromatography detection on the gas-phase component in the first closed system to obtain the target peak area of a characteristic chromatographic peak of the target volatile substance in the gas-phase component in the first closed system, so as to obtain the residual amount of the target volatile substance in said sample on the basis of the target peak area and a standard curve of the peak area and the residual amount of the target volatile substance under the preset condition.

[Problem] To provide a workpiece processing film and a workpiece processing method with which it is possible to hold a workpiece while keeping an attachment surface clean by being attached to the workpiece during workpiece processing. [Solution] This workpiece processing film is used for processing a workpiece, wherein: the workpiece processing film is a substrate-less double-sided adhesive film; and when 10 μL of a toluene solvent, obtained by immersing a workpiece processing film having a size of 80 mm×100 mm in 15 g of toluene at 25ºC for 24 hours, is measured by gel permeation chromatography, and the measurement results are shown as a chromatogram in which the vertical axis is a detection voltage and the horizontal axis is an elution time from the introduction of the toluene solvent to the elution from a column, the peak area of a detection component from an elution time corresponding to a time when the number-average molecular weight in terms of standard polystyrene is 2,500,000 to an elution time corresponding to a time when the number-average molecular weight in terms of standard polystyrene is 200 is at most 4,000 mV∙sec.

The present invention discloses a method for constructing a characteristic spectrum of Trillium gracile for distinguishing Trillium gracile and its processed products and counterfeits, and its application. By optimizing column temperature and flow rate, optimizing chromatographic columns and other conditions, the present invention allows the Trillium gracile characteristic spectrum to contain more information, with a more stable baseline and better chromatographic peak separation. Through multi-batch testing, common peaks are selected and identified using reference substances. On this basis, Trillium gracile and Trillium gracile can be quickly distinguished through different chromatographic peaks. Simultaneously, through mathematical and statistical analysis, characteristic peaks that can distinguish Trillium gracile from vinegar Trillium gracile slices are optimized, and relative peak areas are optimized, providing a rapid and information-rich characteristic spectrum construction method for quality control analysis of distinguishing Trillium gracile from vinegar Trillium gracile slices.

The application discloses a method for drawing the dissolution curve of perphenazine tablets by high performance liquid chromatography, comprising the following steps: adding perphenazine tablets and preheated dissolution medium into a plurality of dissolution cups in sequence under the light-proof environment; using a dissolution instrument to obtain dissolution liquid by sampling the plurality of dissolution cups for multiple times, 5mL of the dissolution liquid is sampled each time and the isothermal dissolution medium is supplemented at the same time; filtering the dissolution liquid, taking the filtered liquid to obtain the test sample solution, and storing the test sample solution for use in the dark; preparing the control sample solution with the perphenazine tablet concentration of 2.012ug / mL and 4.024ug / mL respectively, and storing the control sample solution for use in the dark; using a high performance liquid chromatograph, sucking the test sample solution and the control sample solution into the high performance liquid chromatograph according to preset chromatographic conditions; recording the peak area, and calculating the dissolution amount at each time point according to the formula; taking the dissolution time as the horizontal coordinate and the accumulated dissolution amount at each time as the vertical coordinate, and drawing the dissolution curve.

The invention belongs to the technical field of analysis and detection, and particularly relates to a sulfur hexafluoride isotope abundance detection method. The sulfur hexafluoride isotope abundance detection method provided by the invention comprises the following steps: detecting a to-be-detected sample by using a gas chromatograph-mass spectrometer to obtain a total ion flow chromatogram of sulfur hexafluoride; the gas chromatography test conditions are as follows: a DB-5MS capillary column is adopted, the split ratio is (20-80): 1, and the sample size is 1-10 L; the mass spectrum test conditions comprise that the voltage of a multiplier is + 300 to + 600, and the half-peak width is less than 0.6; and carrying out < 32 > SF < 5 + >, < 33 > SF < 5 + > and < 34 > SF < 5 + > ion extraction on the total ion chromatogram of sulfur hexafluoride to respectively obtain the peak area of < 32 > SF < 5 + >, the peak area of < 33 > SF < 5 + > and the peak area of < 34 > SF < 5 + >, and calculating the abundance of < 32 > SF < 5 + >, the abundance of < 33 > SF < 5 + > and the abundance of < 34 > SF < 5 + >. The detection method provided by the invention has the advantages of economical efficiency, high analysis speed and high accuracy.

This polythiol composition comprises a compound (A) represented by formula (1) and a compound (B) represented by formula (2). In high-performance liquid chromatography measurement performed using a prescribed detector, the peak area of the compound (B) is 9.0 area% or less with respect to 100 area% of the peak area of the compound (A). (In formula (1), the plurality of R's are identical or different from each other, and each represent a divalent hydrocarbon group having 1-6 carbon atoms.) (In formula (2), the plurality of R's are identical or different from each other, and each represent a divalent hydrocarbon group having 1-6 carbon atoms. a1, b1, c1, d1, e1, f1, g1, and h1 are identical or different from each other, each represent an integer of 0-3, and the sum of the same is 6.)

The invention discloses a method for detecting a plurality of related impurities of Iguratimod by utilizing HPLC (High Performance Liquid Chromatography), which comprises the following steps: weighing impurity reference substances with known concentrations, respectively preparing a plurality of mixed standard solutions, carrying out high performance liquid chromatography analysis on the mixed standard solutions at each concentration level, and recording the retention time and peak area of each impurity; for each impurity, drawing a relational graph between the peak area and the known concentration; performing high performance liquid chromatography analysis on the to-be-detected sample according to the same condition, and recording the retention time and peak area of all peaks; comparing the retention time of each peak in the to-be-detected sample with the retention time of the known impurities in the standard solution, and determining the types of the impurities in the to-be-detected sample; and calculating the corresponding concentration by using the drawn relational graph according to the peak area of each impurity peak in the sample to be detected. The method is simple to operate, good in specificity, high in sensitivity and accuracy, and capable of rapidly and accurately detecting 16 related substances in Iguratimod.

The invention discloses a method for measuring the content of bis (2-ethylhexyl) adipate in liquid paraffin, which comprises the following steps: firstly, preparing a group of standard solutions with different mass concentrations, and respectively carrying out gas chromatography test on each standard solution by adopting a gas chromatography method; drawing a standard working curve corresponding to each standard solution by taking the mass concentration of the standard solution as an abscissa and the quantitative chromatographic peak area as an ordinate; and carrying out gas chromatography test on the sample solution to be tested, substituting the measured quantitative chromatographic peak area into the standard working curve, taking the mass concentration of the corresponding standard solution as the mass concentration of the sample solution to be tested, and combining with the mass of the added sample to be tested to obtain the content of bis (2-ethylhexyl) adipate in the liquid paraffin. According to the determination method disclosed by the invention, the content of the bis (2-ethylhexyl) adipate in the liquid paraffin can be rapidly and accurately determined.