Dear Aigars,

The filter manufacturer is irrelevant. What you have to think about is ... does this pore size will be good for what I want to measure?

In fact you can use nitrocellulose membrane filters, glass fiber filters whatever you want. The pore size is the factor you should consider and depends on what you want to measure (total chlorophyll content, chlorophyll by size fraction – fractionated chlorophyll content {0.47, 0.7, 2, 20, >20 microns}). There is a lot of pore size available and lots of providers.

I suppose you will extract the Chl in acetone 90%, 24h at 4ºC (the most common technique), you will just have to measure a blank with an unsued filter and acetone 90% and perform the extraction as if it was a sample. You will be then able to correct your samples values with the background of the specific filter you choose.

In the case of nitrocellulose filters, they will dissolve in acetone which is useful in lots of cases.

Best regards,

Sébastien

Dear Aigars

Since 1987 I always use Whatman GF/F everytime I have to measure chlorophyll in a very common ways as mentioned by other colleagues. i never found any problems although usually extracted them from quite muddy seawater typical of intertidal areas in big city. 

I agree with Norma Afiati, we always use filters GF/F.

I am also wondering if there are any cheaper and succesfull filter brands for chl-a measurements.

What is the disadvantage of nitrocellulose filters ?