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

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 object of the present invention is to provide a method for determining vitamin A and vitamin E in animal source food. Specifically, the present invention uses solid-phase extraction and high-performance liquid chromatography to establish an online solid-phase extraction-high-performance liquid chromatography analysis method for simultaneously determining vitamin A and vitamin E in animal-derived foods. In addition, the invention also provides an online solid-phase extraction analysis system for detecting vitamin A and vitamin E.

The invention discloses a method for measuring the diffusion coefficient of on-site soil solute migration with flux conservation in the whole process. First, identify the groundwater flow field to determine the main and secondary migration directions of solutes in groundwater in the soil; then, based on the flux conservation of solutes, establish a mathematical model for simulating soil solute movement; determine the field experimental conditions for the mathematical model; Under boundary conditions, non-converted solutes were injected in the form of injection sources, and the radial flow observation method was used to measure the concentration of non-converted solutes in the main and secondary migration directions with time; the relationship between the diffusion coefficient and the average pore flow velocity The relationship diagram and the influence of soil and pore average velocity on the diffusion coefficient are analyzed, and the diffusion coefficient is determined based on the flux conservation of the whole process of the non-transformed solute. The invention establishes a mathematical model, simulates the movement of soil solute, is easy to operate, has high measurement accuracy, is easy to build an experimental model, is easy to realize conditions, has rich and diverse samples, and has intuitive results.

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 and ammonium 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 to obtain 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.