Three Types of Filter Paper
Qualitative filter paper refers to qualitative analysis filter paper. Qualitative analysis filter paper is relative to quantitative analysis filter paper and chromatography qualitative analysis filter paper.
Filter paper is a kind of paper with good filtration performance. Its paper is loose and has strong absorption property to the liquid. The filter paper commonly used in the analysis laboratory is used as a filtration medium to separate the solution from the solid. At present, the filter paper produced in China mainly contains quantitative analysis of filter paper.
Classification: qualitative analysis of filter paper and chromatography qualitative analysis filter paper three kinds.
1. Quantitative analysis filter paper: Quantitative analysis filter paper in the manufacturing process, the pulp after hydrochloric acid and hydrofluoric acid treatment, and after washing with distilled water, most of the impurities in the paper fiber removed, so the residual ash after burning is very small, almost no impact on the analysis results, suitable for precision quantitative analysis.
At present, the quantitative analysis filter paper produced in China can be divided into three types: fast, medium and slow speed. On the filter carton, white band (fast), blue band (medium speed) and red band (slow speed) are used as markers for classification. The shapes of the filter paper are round and square. According to the diameter of the circular paper, the specifications are divided into d9cm, dllcm, d12.5cm, d15cm and d18cm. The square quantitative filter paper has 60cm * 60cm and 30cm * 30cm.
2. qualitative analysis: qualitative analysis of filter paper filter residual ash more generally, only qualitative analysis and general solution for filtering precipitation or suspension, can not be used for quality analysis. Qualitative analysis and quantitative analysis of filter types and specifications of filter paper is basically the same, said fast, medium and slow, but printed on fast, medium and slow words. However, attention should be paid to the use of quantitative and qualitative analysis of filter paper for filtration on the boxes of filter paper.
The general use of natural filtration by filter paper, and the ability to entrap solid particles, liquid and solid separation:
Due to the filter mechanical strength and toughness is as little as possible with a way to filter filtration, such as must accelerate the filtration speed, to prevent wear and lead to failure in the filter filter, air filter, according to the pumping force in the funnel stacked 2~3 layers of filter paper, in vacuum, in a first pad leakage. Dense layer of cloth, top Filter paper filtration;
(3) filter paper should not filter hot concentrated sulfuric acid or nitric acid solution.
3. chromatography filter paper chromatography filter paper: qualitative analysis is mainly used as carrier in paper chromatography method, qualitative analysis of the analyte filter with 1 and 3 both qualitative separation, each divided into fast, medium and slow 3.
The pore size of the qualitative filter paper is irregular. Usually, the pore size of the qualitative filter paper is large and the quantity is small. You can try using the quantitative filter paper, the filtration speed is different, the aperture is also different. The general qualitative filter paper has large aperture and no strict rules. Quantitative filter paper divided into fast, medium and slow 3, its diameter is about 80 ~ 120 respectively, 30 ~ 50 micron micron and micron and 1 ~ 3.