Page 14 - 4_TOC special applications

LAAN-A-TC-E027

Application Total Organic Carbon Analysis

News Characterization of Algae by TOC Measurement

No.O50

Global warming due to the excessive use of fossil fuels <Measurement Conditions>
is becoming a problem which has prompted and Analyzer : Shimadzu TOC-LCPH total organic carbon analyzer
accelerated the search for alternative fuels. Among the Catalyst : Standard catalyst
more attractive alternatives is biomass fuel, which is Measurement item : TOC (TC–IC)
attracting considerable attention. Microalgae can be Calibration curve : 1-point calibration curve using 1000 mg/L potassium
hydrogen phthalate aqueous solution
used for the production of oil without competing with Sample 1 : Culture solution containing suspended microalgae cells
food production, and to a greater extent than other Sample 2 : Culture solution with microalgae cells removed by filtration
biofuels, its productivity per unit time and area is high, Water sampling method : Sample 1 water was sampled while stirring with a
magnetic stirrer.
while arable land selection possibilities are great. As for
the practical use of microalgal biomass, various studies
have been conducted at each stage of its production,
including stock selection and breeding, cultivation, n Measurement Results
harvesting, oil extraction, and purification. The increase in total carbon (TC), total organic carbon
The Shimadzu TOC-L Series combustion-type total (TOC) and inorganic carbon (IC) in five types of
organic carbon analyzer, with its powerful organic microalgae culture and cells are shown in Fig. 1 and
substance oxidation features, permits the complete Fig. 2, respectively.
oxidization and measurement of samples such as It became apparent from the results that organic
microalgae cell culture suspensions. material take-up and release by the cells varied
Here, we introduce an example of a unique application depending on the type of microalgae and the duration
in which the TOC-LCPH total organic carbon analyzer is of the culture period. Further, in regard to the
used to characterize microalgae by directly measuring, microalgae that form the shells of calcium carbonate,
without conducting any pretreatment, the TOC content the results suggested that such shell formation
in a suspended culture of microalgae cells. information can be obtained using IC measurement.
The data presented here was provided by the University To express these pieces of information that include the
of Tsukuba Shiraiwa laboratory. type, nature and growth state of microalgae, a TOC
T. Iharada, M. Tanaka analyzer can be utilized for screening of the microalgae
and investigation of culture conditions.

n Analytical Method
Five types of microalgae A – E were cultured for 3 to 14
days, and at the start, after several days, and at the end
of culturing, TOC measurement was conducted for
sample 1, consisting of the various types of microalgae
cells suspended in culture medium, and for sample 2,
consisting of culture obtained by removing the
microalga cells through filtration of sample 1. Then,
from the difference in organic carbon content (TOC) in
samples 1 and 2, we determined the TOC in the
organic material of the various types of microalgae
cells. Also, the turbidity of sample 1 was measured, and
that value was taken as an index of cell mass.