| Summary: | Progress Code: onGoing Maintenance and Update Frequency: notPlanned Statement: Water samples were taken on-board the RV Southern Surveyor. Samples were filtered onboard. Samples were analysed and QC procedures were carried out in the Ocean Colour Laboratory. Pigment analysis 4 litres of sample water was filtered through a 47 mm glass fibre filter (Whatman GF/F) and then stored in liquid nitrogen until analysis. To extract the pigments, the filters were cut into small pieces and covered with 100% acetone (3 mls) in a 10 ml centrifuge tube. The samples were vortexed for about 30 seconds and then sonicated for 15 minutes in the dark. The samples were then kept in the dark at 4 °C for approximately 15 hours. After this time 200 µL water was added to the acetone such that the extract mixture was 90:10 acetone:water (vol:vol) and sonicated once more for 15 minutes. The extracts were centrifuged to remove the filter paper and then filtered through a 0.2 µm membrane filter (Whatman, anatope) prior to analysis by HPLC using a Waters high performance liquid chromatograph, comprising a 600 controller, 717 plus refrigerated autosampler and a 996 photo-diode array detector. Pigments were separated using a stainless steel 25 cm x 4.6 mm I.D. column packed with ODS2 of 5 µm particle size (SGE) with gradient elution as described in Wright et al., [1991]. The separated pigments were detected at 436 nm and identified against standard spectra using Waters Millenium software. Concentrations of chlorophyll a, chlorophyll b, b,b-carotene and b,e-carotene in sample chromatograms were determined from standards (Sigma) and all other pigment concentrations were determined from standards of purified pigments isolated from algal cultures. Spectral absorption. 2 litres of sample water was filtered through a 25 mm glass fibre filter (Whatman GF/F) and the filter then stored flat in liquid nitrogen until analysis. Optical density spectra for total particulate matter were obtained using a GBC 916 UV/VIS dual beam spectrophotomete Credit ...
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