70 results about "Acid digestion" patented technology

The invention discloses a forensic medical diatom inspection method based on mixed acid digestion. The forensic medical diatom inspection method comprises the steps of optical microscope inspection and scanning electron microscope inspection. The optical microscope inspection at least comprises the steps of: (1) performing a blank test; (2) performing mixed acid digestion by adding concentrated nitric acid, concentrated hydrochloric acid and a hydrogen peroxide solution in a sample to be tested and digesting in a manner of heating in water bath; (3) centrifuging and precipitating; (4) coating on a sheet and sealing by using epoxy resin; and (5) performing diatom qualitative and quantitative analysis. The scanning electron microscope inspection at least comprises the steps of: (1) performing a blank test; (2) performing mixed acid digestion by adding concentrated nitric acid, concentrated hydrochloric acid and a hydrogen peroxide solution in a sample to be tested and digesting in a manner of heating in water bath; (3) performing vacuum filtration; (4) automatically taking pictures and storing images by a scanning electron microscope; and (5) performing diatom qualitative and quantitative analysis. The forensic medical diatom inspection method based on the mixed acid digestion, disclosed by the invention, is high in sensitivity, efficient, safe, environment-friendly and exact in qualitative and quantitative analysis, and has good application prospect in the forensic medical drowning diagnosis practice.

Catalytic reactions conducted during acid digestion of cellulose materials, including paper, a wide range of grasses including prairie grass, switch grass, pine wood sawdust, bagasse dried after sugar cane processing, cotton, waste cellulose products and starch materials, are taught for direct conversion to ethanol. The cellulose material is thoroughly wet in concentrated sulfuric acid in the presence of transition metal complexes possessing a degree of symmetry. Ethanol formed during the reaction can be removed by distillation affording a continuous process.

The invention discloses a method for industrially producing silicate phosphate from rice husk carbon, which comprises the following steps of: smoldering and carbonizing rice husks to obtain rice husk carbon; performing acid digestion or acid firing on the rice husk carbon to obtain initial activated carbon; and performing dustproof and explosion-proof sealed packaging treatment on the initial activated carbon, and performing intermediate temperature, sub-high temperature and high temperature activation to finally prepare high-quality silicate phosphate and activated carbon. The method overcomes the defect of low yield of silicate phosphate prepared from the rice husk carbon in the prior art. The process method has the advantages of simpleness, reasonableness, convenient operation and highseparation rate of carbon and silicon elements from the rice husk carbon, overcomes the technical barrier of intermediate and high temperature activation of the rice husk carbon, can directly producethe high-quality silicate phosphate and activated carbon from the rice husk carbon, effectively improves the economical and social benefits of the rice husks, can realize the concept of conservation,low carbon and economy, and provides a new way for agricultural industrialization.

The invention discloses a method for quantitative detection of chromium element valence and content in a chromium-containing substance. The method includes: adding a chromium-enriched yeast stem cell sample into an alkali digestive juice to conduct treatment, then performing centrifugation, adjusting the pH of conditioning fluid to obtain a to-be-detected solution; preparing a chromium standard solution, performing testing, and establishing a chromium stand solution standard curve; subjecting the to-be-detected solution to high performance liquid phase separation, using an inductively coupled plasma mass spectrometry to analyze the Cr(VI) content, conducting acid digestion, and directly using inductively coupled plasma mass spectrometry to analyze the total chromium content of the sample, calculating the Cr(III) content through the difference of the total chromium content and the Cr(VI) content of the sample. The method provided by the invention improves the accuracy of sample measurement, has the characteristics of small sample size and short detection time, saves the sample preparation amount and measurement time, can accurately and quantitatively measure chromium-enriched yeasts with different chromium enrichment amounts.