A comparison of the retention capability among three different glass-fiber filters used for chlorophyll-a determinations

Bio-Optical Properties of the Inner Continental Shelf off Santos Estuarine System, Southeastern Brazil, and their Implications for Ocean Color Algorithm Performance

“…Chlorophyll-a concentration (Chl, mg m -3 ) was determined by spectrophotometric methods, in accordance with SCOR- UNESCO (1966), from samples retained in AP-40 Millipore filters (SALDANHA-CORRÊA et al, 2004) and extracted in 90% acetone. Independently, samples for Chl were also determined using a calibrated Turner Designs 10-005R fluorometer, equipped with the non-acidification filter set (WELSCHMEYER, 1994).…”

Nitrogen regeneration in the NE Atlantic Ocean and its impact on seasonal new, regenerated and export production

“…The efficiency of glass fiber filters (mainly Whatman GF/F) has been repeatedly verified in marine environments (e.g. Altabet 1990, Raimbault et al 1999, Diaz & Raimbault 2000, Saldanha-Corrêa et al 2004. Comparisons of different types of filters, including 0.2 μm Anopore aluminium oxide membranes (Altabet 1990, Slawyk & Raimbault 1995, indicated that a significant fraction of the particulate nitrogen collected by 0.2 μm Anopore membranes could pass through GF/F filters, and the relative importance of the fraction that was neglected increased with depth.…”

“…In such conditions, the use of Anopore aluminium oxide 0.2 μm membranes should not be avoided, but the problem persists due to their low filtration speed, high cost and potential incompatibility with mass spectrometry analysis. In spite of the existence of 2 alternative glass fiber filters (AP-40 Millipore and GF-5 Macherey Nagel) with approximate nominal porosities (0.45 and 0.4 μm respectively), their retention performance is compromised in oligotrophic conditions (Saldanha-Corrêa et al 2004). New technology is needed to ensure routine filtration and analysis of the smallest fraction of marine ultraplankton.…”

Measurement of light absorption by aquatic particles: improvement of the quantitative filter technique by use of an integrating sphere approach

“…In the following, all measurements were made with combusted GF-5 filters. Saldanha et al (2004) [35] showed that this filter type has the same particle retention characteristics as the commonly used GF/F filter type.…”