Nutrients
Nutrients
Spectrophotometric nutrient analyses for environmental studies and lab experiments
Location: Wilhelmshaven
Responsibility: Carola Lehners
*Please note: Informations about sample sizes and measured ranges are only guide values. They do not replace a detailed consultation with the responsible MCA contact!
Reader
Microplate Reader, Thermo Fisher Multiskan GO
Measured parameters: Total alkalinity (TA), ammonium (NH4+), nitrite (NO2-), nitrate (NO3-), nitrate & nitrite (NOx), silicate (Si(OH)4), phosphate (PO43-).
Sample matrix: Aqueous (sea-, fresh-, porewater)
Sample preservation: Filtration (0.2-0.45 µm with cellulose acetate, PES, PTFE). Poisoning with 3.5% HgCl2 (1.75g HgCl2 p.a. in ultrapure water) solution: 30 µL per 10 mL sample.
Sample storage: Plastic vials (PP, PE), fridge (4°C)
Sample volume: 20 mL for preserved samples, 1-2 mL for directly measured, non-preserved samples
Measured range: 0-10 mM (TA), 0-100 µM (NH4+), 0-10 µM (NO2-), 0-50 µM (NO3-), 0-100 µM (NOx & Si(OH)4), 0-35 µM (PO43-)
QUAATRO
Continuous Segmented Flow Analyzer, SEAL QUAATRO
Measured parameters: ammonium (NH4+), nitrite (NO2-), nitrate & nitrite (NOx), phosphate (PO43-).
Sample matrix: Aqueous (sea-, fresh-, porewater)
Sample preservation: not possible, only direct measurement of filtered samples!
Sample storage: Plastic vials (PP, PE), fridge (4°C) for short periods
Sample volume: 15 mL
Measured range: 0-10 µM (NH4+), 0-2 µM (NO2-), 0-80 µM (NOx), 0-3 µM (PO43-)
Easychem
Discrete Routine Laboratory Analyzer, Easychem, Systea S.p.A.
Measured parameters: nitrite (NO2-), nitrate & nitrite (NOx), silicate (Si(OH)4), phosphate (PO43-).
Sample matrix: Aqueous (sea-, fresh-, porewater)
Sample preservation: Filtration (0.2-0.45 µm with cellulose acetate, PES, PTFE). Poisoning with 3.5% HgCl2 (1.75g HgCl2 p.a. in ultrapure water) solution: 30 µL per 10 mL sample.
Sample storage: Plastic vials (PP, PE), fridge (4°C)
Sample volume: 5 mL
Measured range: 0-10 µM (NO2-), 0-50 µM (NOx), 0-21 µM (Si(OH)4), 0-10 µM (PO43-)
Specord 40
Photometer, Analytik Jena Specord 40
Measured parameters: nitrite (NO2-), nitrate & nitrite (NOx), silicate (Si(OH)4), phosphate (PO43-).
Sample matrix: Aqueous (sea-, fresh-, porewater)
Sample preservation: Filtration (0.2-0.45 µm with cellulose acetate, PES, PTFE). Poisoning with 3.5% HgCl2 (1.75g HgCl2 p.a. in ultrapure water) solution: 30 µL per 10 mL sample.
Sample storage: Plastic vials (PP, PE), fridge (4°C)
Sample volume: 10 mL
Measured range: 0,01-0,1 µM (NO2-), 0,2-2,0 µM (NOx), 0,35-10,6 µM (Si(OH)4), 0,05-2,1 µM (PO43-)
Literature for analytical methods
Total alkalinity (TA)
Dickson, A. G. (1981). An exact definition of total alkalinity and a procedure for the estimation of alkalinity and total inorganic carbon from titration data. Deep Sea Research Part A. Oceanographic Research Papers, 28(6), 609-623.
Sarazin, G., Michard, G., & Prevot, F. (1999). A rapid and accurate spectroscopic method for alkalinity measurements in sea water samples. Water Research, 33(1), 290-294.
Ammonium (NH4+)
Benesch, R., & Mangelsdorf, P. (1972). Eine methode zur colorimetrischen bestimmung von ammoniak in meerwasser. Helgoländer Wissenschaftliche Meeresuntersuchungen, 23(3), 365-375.
Nitrate & Nitrite (NO3- & NO2-)
Miranda, K. M., Espey, M. G., & Wink, D. A. (2001). A rapid, simple spectrophotometric method for simultaneous detection of nitrate and nitrite. Nitric oxide, 5(1), 62-71.
NOx
Schnetger, B., & Lehners, C. (2014). Determination of nitrate plus nitrite in small volume marine water samples using vanadium (III) chloride as a reduction agent. Marine Chemistry, 160, 91-98.
Silicate (Si(OH)4)
Strickland, J. D. H., & Parsons, T. R. (1972). A practical handbook of seawater analysis.
Fanning, K. A., & Pilson, M. (1973). On the spectrophotometric determination of dissolved silica in natural waters. Analytical Chemistry, 45(1), 136-140.
Phosphate (PO43-)
Itaya, K., & Ui, M. (1966). A new micromethod for the colorimetric determination of inorganic phosphate. Clinica chimica acta, 14(3), 361-366.
Laskov, C., Herzog, C., Lewandowski, J., & Hupfer, M. (2007). Miniaturized photometrical methods for the rapid analysis of phosphate, ammonium, ferrous iron, and sulfate in pore water of freshwater sediments. Limnology and Oceanography: Methods, 5(1), 63-71.