Ashless hardened filter paper for quantitative analysis
Ashless hardened Filter papers are acid hardened which reduce the ash content to an extremely low level.
These filters are produced by a complex elaborate washing process under stringently controlled conditions. Firstly, acid washing is arranged. Then a series of washes in demineralised water come, which increase the strength of the paper, therefore making them particularly suitable for Büchner filter funnels and a wide range of critical analytical filtration operations.
Through this process, a maximum ash content of <0.006% is attained, which means that no contaminants are introduced when filtering. Also, full compliance with international standards on this subject is achieved.
Thanks to the hardened texture, they are often used when the analist must recover the precipitates retained on the filter surface.
Proprietà
DF541 GRADE - Fast filtration
Hardened ashless filter paper with a fast flow rate. Preferably used for the filtration of coarse flocculent and bulky precipitates (as aluminium, chromium or hydroxides of iron, bismuth, cobalt, sulphides of copper, various organic metal precipitates, etc.) and gelatinous precipitates in acid/alkaline solutions during gravimetric analysis.
DF540 GRADE – Medium filtration
Hardened ashless filter paper with medium retention and flow rate.
Extremely strong and pure. With a hard surface, it is recommended for filtering medium-sized precipitates such as most metal sulphides.
High chemical resistance. Used in the gravimetric analysis of metals in acid and slightly alkalinized solutions, pressure filtration.
DF542 GRADE - Slow filtration
Hardened ashless filter paper with high retention and slow flow rate.
High chemical resistance. Often used for filtering very fine precipitates and in gravimetric metal determinations.