Classification and overview of biological reagents
Biological reagent (BR: Biological reagent) refers to the classification of chemical reagents. China's reagent specifications are basically divided by purity (how much impurity content), there are 7 kinds of high purity, spectral purity, benchmark, spectroscopic purity, superior purity, analytical and chemical purity. The state and the competent authority have promulgated three main types of quality indicators: superior grade, graded grade, and chemical grade. (1) Excellent grade pure (GR: Guaranteed reagent), also known as first-class product or guaranteed reagent, 99.8%, this reagent has the highest purity and the lowest impurity content, suitable for important precision analysis work and scientific research work, using green bottles sign. (2) Analytical purity (AR), also known as secondary reagent, has a very high purity of 99.7%, slightly inferior to superior purity, suitable for important analysis and general research work, using a red bottle label. (3) Chemically pure (CP), also known as tertiary reagent, ≥ 99.5%, the purity is quite different from analytical purity, and is suitable for general analysis in industry, mines and schools. Use the blue (dark blue) label. (4) Laboratory reagent (LR: Laboratory reagent), also known as fourth-grade reagent. In addition to the above four levels, there are currently on the market: benchmark reagent (PT: Primary Reagent): specifically used as a benchmark, can directly prepare standard solutions. Spectral pure reagent (SP: Spectrum pure): indicates spectral purity. However, because the organic substance does not show up in the spectrum, sometimes the main component is less than 99.9%, and it must be noted when used, especially when used as a reference substance, calibration must be performed. Reagents whose purity is much higher than that of superior-grade pure are called high-purity reagents (≥ 99.99%). Reagent access rules The solid powder reagent can be taken with a clean horn spoon. When you want to take a certain amount of solid, you can put the solid on paper or watch glass and weigh it on the platform scale. For accurate weighing, use a weighing bottle to weigh on the balance. The liquid reagent is usually measured with a measuring cylinder. The volume of the measuring cylinder is 5mL, 10mL, 50mL, 500mL and so on. When using it, the measured liquid should be injected into the measuring cylinder to keep the line of sight and the lowest part of the liquid concave surface in the measuring cylinder horizontal, and then read The scale on the graduated cylinder gives the volume of liquid. If a small amount of liquid reagent is needed, it can be taken with a dropper. Take care not to touch or insert the dropper on the wall or inside of the receiving container. In order to achieve accurate experimental results, the following rules should be followed when taking reagents to ensure that the reagents are not contaminated and not deteriorated: (1) Reagents must not come into contact with hands. (2) Use a clean medicine spoon, measuring cylinder or dropper to take the reagents. It is absolutely forbidden to use the same tool to continuously take multiple reagents at the same time. After taking one reagent, the tool should be washed (the medicine spoon should be dried) before taking another reagent. (3) After taking the reagent, the cap must be tightly closed. The cap and the dropper must not be misplaced. Zhang Guanli Dai is never allowed to put the bottle back in place after use. (4) The removed reagents can no longer be put back in the original reagent bottles. Single Side Breast Pump Zhejiang Carebao Co., Ltd , https://www.carebao.com