a Coulter Counter to determine the spectrum of particle sizes before
and after filtration. They found that filters removed almost all of the
particles larger than a given pore size, but they retained a considerable
fraction of smaller particles that theoretically could have passed through.
Thus the filters are not suitable for quantitative size fractionation.
This result helps to explain the observation (Menzel, 1966 ; Batoosingh et al., 1969) that immediate refiltration of a sea water sample will
give an additional yield, presumably consisting of particles smaller
than the pore size of the filter, which are retained imperfectly but to
a measurable degree during subsequent filtrations. Menzel, in the
paper cited and in subsequent ones, also suggested the possibility of
adsorption of dissolved organic carbon, but this seems unlikely. P. J.
Wangersky (personal communication) filtered sea water through a
dialysis membrane which removed all organic materials except dissolved substances with a molecular weight of less than 10 000. He
then passed the water through silver filters and found no significant
increment in organic carbon; however, there was an indication of a
slight amount of adsorption on glass fibre filters.
After filtration the samples are kept in a dried or frozen state until
analysis. Both wet oxidation and dry combustion have been used in
the determination of total organic carbon. For a detailed description
and discussion of these methods the reader is referred to Wilson (196l),
Menzel and Vaccaro (1964) and Strickland and Parsons (1965). Strickland and Parsons also described methods for determining protein, lipid,
carbohydrates and crude fibre with sufficient sensitivity to be used in
the analysis of naturally occurring particulate matter.
Krey et al. (1957) developed a method for determining protein in
particulate matter by means of the biuret reaction. They then used
a conversion factor to estimate the quantity of living material. The
difference between total dry weight and the calculated biomass was
then regarded as detritus. This method, with some later elaboration,
has been used widely by Krey and his co-workers and provides useful
comparative data in the various regions studied. However, this work
cannot be compared directly with the data of other investigators, for
there is some protein in non-living particulate matter, and the detritus
is by no means exclusively organic material.
In addition to these general and widely used methods, there will be
references in a later section t o various biochemical studies of a more
limited nature, and the reader is referred to the original literature for
the methods used.
and after filtration. They found that filters removed almost all of the
particles larger than a given pore size, but they retained a considerable
fraction of smaller particles that theoretically could have passed through.
Thus the filters are not suitable for quantitative size fractionation.
This result helps to explain the observation (Menzel, 1966 ; Batoosingh et al., 1969) that immediate refiltration of a sea water sample will
give an additional yield, presumably consisting of particles smaller
than the pore size of the filter, which are retained imperfectly but to
a measurable degree during subsequent filtrations. Menzel, in the
paper cited and in subsequent ones, also suggested the possibility of
adsorption of dissolved organic carbon, but this seems unlikely. P. J.
Wangersky (personal communication) filtered sea water through a
dialysis membrane which removed all organic materials except dissolved substances with a molecular weight of less than 10 000. He
then passed the water through silver filters and found no significant
increment in organic carbon; however, there was an indication of a
slight amount of adsorption on glass fibre filters.
After filtration the samples are kept in a dried or frozen state until
analysis. Both wet oxidation and dry combustion have been used in
the determination of total organic carbon. For a detailed description
and discussion of these methods the reader is referred to Wilson (196l),
Menzel and Vaccaro (1964) and Strickland and Parsons (1965). Strickland and Parsons also described methods for determining protein, lipid,
carbohydrates and crude fibre with sufficient sensitivity to be used in
the analysis of naturally occurring particulate matter.
Krey et al. (1957) developed a method for determining protein in
particulate matter by means of the biuret reaction. They then used
a conversion factor to estimate the quantity of living material. The
difference between total dry weight and the calculated biomass was
then regarded as detritus. This method, with some later elaboration,
has been used widely by Krey and his co-workers and provides useful
comparative data in the various regions studied. However, this work
cannot be compared directly with the data of other investigators, for
there is some protein in non-living particulate matter, and the detritus
is by no means exclusively organic material.
In addition to these general and widely used methods, there will be
references in a later section t o various biochemical studies of a more
limited nature, and the reader is referred to the original literature for
the methods used.