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  • Autocalibration based on dilution of a single concentrated standard is used for the determination of silicate in sea water by the modified molybdenum blue method
Title: Autocalibration based on dilution of a single concentrated standard is used for the determination of silicate in sea water by the modified molybdenum blue method
The silicate (Si) molybdenum blue method was modified by combining oxalate and ascorbic acid into a single reagent and was used for determining Si in sea water samples. The first step of this automated assay protocol was designed to perform either a calibration by a single Si standard prepared in deionized (DI) water, or to dilute samples in the range of 0–160 μM Si to fit into 0–20 μM Si calibration range using a 20 cm flow cell. By designing the assay protocol to function in batch mode, the influence of salinity on calibration was eliminated, thus making the method suitable for analysis of samples collected in the open ocean, coastal areas, or rivers. Reproducibility and accuracy of this method were evaluated by analysis of certified sea water reference materials. Phosphate (P) does not interfere significantly if the Si:P ratio is 4:1 or larger. The limit of detection was 514 nM Si, r.s.d. 2.1 %, sampling frequency 40 s/h, reagent consumption 700 μL/sample, and using deionized water as the carrier solution.  more » « less
Award ID(s):
1924690
PAR ID:
10535450
Author(s) / Creator(s):
; ; ;
Publisher / Repository:
ELSEVIER
Date Published:
Journal Name:
Talanta
Volume:
276
ISSN:
0039-9140
Page Range / eLocation ID:
126183
Subject(s) / Keyword(s):
Programmable flow injection Lab-on-valve Silicate Salinity Phosphate interference Autodilution
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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