67results about How to "Analytical methods are accurate and reliable" patented technology

The present invention aims to provide a method for determining vitamin A and E in animal-derived food. Specifically, the invention employs the solid phase extraction and high performance liquid chromatography coupling technique to establish an on-line solid phase extraction-high performance liquid chromatography analytical method for simultaneous determination of vitamin A and vitamin E in animal-derived food. Furthermore, the invention also provides an on-line solid phase extraction analysis system for the detection of vitamin A and vitamin E.

The invention discloses an analysis method for amide compounds. The analysis method adopts a gas chromatography-mass spectrometry method. According to the invention, under the optimized analysis conditions, very good chromatographic peaks of the five amide compounds can be obtained within 15 min; very good separating effects can be obtained; the linearities of all the target compounds are good within a concentration range of 0.01-10 mg/L; the correlation coefficients are all greater than 0.9995; the detection limits reach 0.01 mg/kg; the relative standard deviations are smaller than 2.5%; the recovery rates of standard addition are 80-105%. The analysis method is convenient, fast, accurate, and reliable, and can meet REACH regulation requirements on hazardous amides.

The invention relates to a method for discriminating Chinese mitten crabs in different producing areas, which is characterized by comprising the following steps of: fishing for the Chinese mitten crabs in different producing areas and then placing in a refrigerator for preservation; after thawing the crabs, taking the third ambulatory legs at the left sides of crab carapaces for element analysis,and then drying the third ambulatory legs in a drying oven to the constant weights; grinding dry samples by using agate mortars for homogenization, and then placing in the drying oven at room temperature; weighing and placing the dry samples into a digestion pipe, and adding concentrated nitric acid to the digestion pipe for digesting the dry samples; transferring the digested samples into a quantitating bottle, and then determining the volume of the samples by using pure water to obtain a solution to be measured; measuring the concentration values of trace elements in the solution to be measured and calculating the corresponding concentration values in the third ambulatory leg dry samples of the Chinese mitten crabs. The analysis method in the invention has reliability and favorable precision, and can effectively discriminate Chinese mitten crab crowds respectively produced in the Jiangsu Yangcheng Lake, the Yong Lake, the Changdang Lake and the Jiangxi Junshan Lake and establish a specific trace element geographical fingerprint library and a discrimination function equation of the Chinese mitten crabs in various areas.

The present invention adopts piezoelectric gene diagnosis chip and frequency detection instrument and utilizes multiple PCR technique to make temp. circulation of hydridization-extension-denaturation to amplify, target gene, monitor and obtain the linear relationship of frequency change and target gene concentration, then uses external standard curve to make quantitative analysis. Said apparatus comprises shell body, power supply and its connected circuit, and main body module, analysis, software, sample preparation module, positioning liquid flow module and piezoelectric gene diagnosis chip detection module. Said invention is suitable for clinical diagnosis and molecular mechanism research, monitoring epidemic disease and infections disease spreading and harmful microbial genesis and diffusion.

The invention provides a method for determining the content of six impurity elements of manganese, phosphorus, arsenic, lead, zinc and copper in permanent magnetic ferrite mixed materials. According to the method, a to-be-determined sample is added into concentrated hydrochloric acid and concentrated nitric acid and is dissolved at the low temperature, the sample is in a volumetric flask in a constant-volume mode, and the sample, the concentrated hydrochloric acid and the concentrated nitric acid are shaken up for determining. Prepared manganese, phosphorus, arsenic, lead, zinc and copper standard solutions are used for making a manganese, phosphorus, arsenic, lead, zinc and copper spectral line intensity-mass fraction working curve on a plasma atomic emission spectrometer, the curve is used for analyzing the to-be-determined sample, and the content of the manganese, the phosphorus, the arsenic, the lead, the zinc and the copper in the permanent magnetic ferrite mixed materials is obtained. According to the method, operation is convenient and rapid, the analysis cost is low, the determining result has the good stability, reproducibility and accuracy, and the determining requirements for the impurity elements of the manganese, the phosphorus, the arsenic, the lead, the zinc and the copper in the daily permanent magnetic ferrite mixed materials can be met. According to the analysis method, adopted chemical reagents are few, the pollution to the environment is small, the analysis cost is low, the multiple elements can be determined at the same time, the analysis efficiency is improved, and labor intensity of analysis and operation personnel is reduced.

The invention provides an in-situ measurement method for unsaturated hydrodynamic dispersion coefficients of soil with structural differences. The method comprises the following steps: determining structural differences of soil profiles on the basis of soil particle size analysis; enabling water and solutes in soil to enter a redistribution process on the basis of the boundary condition of fixed water head, and determining soil matrix potential and solution concentration profile distribution at different moments by arranging sensors; providing a soil hydrodynamic dispersion coefficient relation equation on the basis of a mass continuity principle in the redistribution process, determining parameters of the soil hydrodynamic dispersion coefficient relation equation with a central difference method according to the soil matrix potential and solution concentration distribution at two adjacent moments, and further determining the unsaturated hydrodynamic dispersion coefficients of the soil with different texture. The method has the advantages of clear physical conception, simple computational formula, easy operation, high measurement precision and direct experimental result, and more importantly, the hydrodynamic dispersion coefficients of the soil with the structural differences can be determined, and the method has originality in the field.

The invention discloses an ion chromatography detection method for negative ions in a sodium azide solid product or sodium azide mother liquor. The sodium azide solid product or the sodium azide mother liquor is analyzed by the ion chromatography detection, so that sodium azide and negative ions (the negative ions exist in the form of salt) can be fully separated; meanwhile, the species of the negative ions is judged or/and the content of the negative ions is calculated according to a chromatographic peak out result; a used flowing phase is a mixture aqueous solution of sodium carbonate and sodium hydrogen carbonate. The analysis method is accurate and reliable; the operation is simple, convenient and feasible; the analysis method is easy to popularize; the contents of sodium nitrite in the sodium azide solid product and the mother liquor can be detected, the difficulty in separating sodium azide from sodium nitrite is solved, and an extremely good supplementing effect is achieved on the national standard GB/T26754-2011 Industrial Sodium Azide. Furthermore, multiple negative ion components in the sodium azide mother liquor can be detected, and great guiding significance in industrial production of sodium azide is acheived.

The invention provides a spur gear tooth root crack propagation rule analysis method based on finite element simulation. The method comprises the following steps of firstly, establishing a gear simulation model by utilizing ANSYS, then completing load loading, mesh generation, boundary condition setting, stress solving and other work on the basis of the model, importing the model into FRANC3D to obtain data such as an expansion path and direction of a gear tooth root crack, stress intensity factor change in a crack expansion process, crack life prediction and the like, and finally, analyzing afinite element simulation result to obtain a spur gear tooth root crack propagation rule. According to the method, the propagation rule of the spur gear tooth root cracks is researched based on a numerical simulation method, the crack propagation situation is tracked, the distribution rule of crack tip stress intensity factors and a fatigue life prediction curve are obtained, the calculation precision is high, the experiment speed is higher, the efficiency is higher, and convenience is brought to the depth research of gear tooth root crack propagation.

The invention relates to a method for detecting the content of swainsonine in locoweed endophytic fungi. The method comprises the steps: pre-treating an endophytic fungi hyphae sample to prepare a test solution; using a high performance liquid chromatograph evaporative light-scattering detector to detect the swainsonine in the locoweed endophytic fungi; taking a mixed solution of acetonitrile andammonium acetate buffer solution as a mobile phase, wherein the volume ratio of acetonitrile to ammonium acetate is 0.2-2 to 0.2-2; separating the swainsonine from other materials in the test sample by an HILIC (Hydrophilic Interaction Chromatography) column; and constructing a map by logarithm of swainsonine in different concentrations and logarithm of a corresponding response peak area so as toobtain a standard curve of the swainsonine. According to the method, the swainsonine in the endophytic fungi Undifilum oxytropis can be effectively separated, and the method can be directly applied to the quantitative analysis of the swainsonine. The method is good in separation effect, strong in specificity and high in accuracy, and the analysis method is reliable.

The invention discloses a terahertz absorption peak position extraction method based on a discrete maximum value. A characteristic absorption peak in a terahertz absorption coefficient spectrum plays an important role in the identification research of a peak-containing target object in the spectrum, so that the identification of the characteristic absorption peak and the determination of the characteristic absorption peak position are necessary work in the identification research. According to an adjoint inflection point method, a baseline spectrum and a differential spectrum corresponding to an original terahertz absorption coefficient spectrogram are obtained mainly by searching inflection points and adjoint inflection point pairs existing in a terahertz absorption coefficient spectrum, and then peak position information in the differential spectrum is determined according to a discrete maximum value method, namely, the absorption peak position of the original spectrogram of a substance. According to the method, weak peaks existing in the terahertz absorption coefficient spectrogram of the substance can be searched, information extraction and accurate judgment of the substance are achieved through the characteristic absorption peaks, and therefore the detection efficiency of the terahertz technology on the substance is improved.

The invention discloses an automatic detection method for continuous increase of vibration of mechanical equipment. The automatic detection method comprises the following steps of: step 1, performingfeature extraction on vibration signal waveform data acquired at the current moment of equipment vibration monitoring; 2, updating and calculating a vibration reference, comparing a feature value V obtained in the step 1 with the vibration reference, and judging whether the vibration reference is to be updated or not; 3, calculating an increase result of the data collected at the current moment according to the vibration reference value; and 4, judging whether the data acquired at the current moment is continuously increased or not according to a calculation result in the step 3. According tothe method, the equipment vibration reference standard is automatically calculated and updated, then the increase results of the vibration and the reference standard are collected in real time throughcalculation equipment; whether the increase results are larger than the increase results corresponding to the previous continuous growth point or not is judged; and automatic detection of the continuous increase of equipment vibration is achieved.

The invention relates to a detection method for complete separation of mexiletine hydrochloride associated substances. The method comprises the steps that by using high performance liquid chromatography, detection is conducted, wherein according to chromatographic conditions, octadecylsilane bonded silica gel is used as a filler of a chromatographic column, before feeding, a ghost peak capture column is added, a mixed solution of a sodium acetate buffer solution and methyl alcohol serves as a moving phase A in the chromatographic conditions, methyl alcohol serves as a moving phase B, and gradient elution is conducted. The detection method is high in column efficiency, high in sensitivity and high in repeatability, the degree of separation of a main peak from various impurities is high, theoperation is simple, and an effective and reliable analyzing method is provided for determining the mexiletine hydrochloride associated substances.

The invention discloses a detection method of polyhydric alcohol which comprises the following steps: preparing a test sample solution from a test sample by using a diluent, and detecting the test sample solution by using a gas chromatographic method under the chromatographic conditions that a capillary chromatographic column of polyethylene glycol is used as a stationary phase, the temperature of a sample inlet is 200-250 DEG C, the temperature of a detector is 220-350 DEG C, the column temperature is detected according to programmed temperature rise, wherein the specific temperature rise program is as follows: the initial temperature is 110-130 DEG C, the temperature is raised to 220-240 DEG C at the speed of 5-15 DEG C/min, and the temperature is kept for 0-30 min; the polyol is at least one of diethylene glycol, dipropylene glycol and tripropylene glycol. The method is simple to operate, good in separation degree, sensitive and efficient; and diethylene glycol, dipropylene glycol and tripropylene glycol can be detected. The method can be applied to detection of polyhydric alcohols in the ornidazole injection, and a reliable analysis method is provided for quality control analysis of the ornidazole injection.