There are many different types of filter paper. The type that best meets the analytical needs should be used.
Parameters:
(1) ashing of paper for gravimetric analysis
(2) pH of suspension
(3) type of precipitate
(4) need to remove precipitate from filter paper surface (if not ashed)
|
Gravimetric Analysis |
pH |
Precipitate |
Remove Precipitate |
Whatman Type |
|
yes |
strong acid or base |
fine |
NA |
542 |
|
yes |
strong acid or base |
coarse or gelatinous |
NA |
541 |
|
yes |
strong acid or base |
other |
NA |
540 |
|
yes |
not strong acid or base |
fine |
NA |
42 or 44 |
|
yes |
not strong acid or base |
coarse or gelatinous |
NA |
41 |
|
yes |
not strong acid or base |
other |
NA |
40 or 43 |
|
no |
NA |
fine |
yes |
50 |
|
no |
NA |
coarse or gelatinous |
yes |
54 |
|
no |
NA |
other |
yes |
52 |
|
no |
NA |
NA |
no |
qualitative |
where:
• 540, 541 and 542 are hardened and ashless.
• 40 to 44 are ashless grades.
• 50, 52 and 54 are nonashless, hardened grades.
Specialty: Clinical Laboratory
