LC-OCD-OND

The LC-OCD-OND system can be used for the highly sensitive quantitative determination of colloidal and dissolved organic carbon and nitrogen compounds as well as nitrate and ammonium in aqueous solutions. Natural organic matter is separated into specific fractions such as biopolymers, humic substances, building blocks, low-molecular-weight (LMW) acids, LMW neutrals and hydrophobic compounds. The detection limit is in the low ppb range for organic C and N.

Equipment

• Liquid chromatography system with organic carbon, organic nitrogen and UV detector (Model 9; DOC-Labor Dr. Huber).
• The chromatographic column is filled with a polymer based on polyacrylate (Toyopearl TSK HW50S).
• An Autosampler (MLE Dresden) is available for feeding of liquid samples.
• The system is equipped with a non-dispersive infrared detector (ABB), an UV detector (Knauer; wavelength 254 nm) and an organic nitrogen detector (Knauer; wavelength 220 nm).

Sample preparation

• A sample volume of at least 5 ml is required for each measurement (the use of lower sample volumes might be possible depending on the DOC content but must be discussed in advance).
• Samples can be delivered in glass vials or PP-tubes.
• During sampling and sample preparation, keep sample away from perfume, organic solvents, felt pens etc.
• Do not acidify samples and indicate pH of sample (only samples with a pH of 3-9 can be measured).
•  If TOC/DOC content of sample is known, please submit the information prior to the measurement of the samples.
• Pre-filtration of samples is generally not necessary, as they are routinely filtered in-line with a 0.45 µm filter (PES-membrane). In-line filtration with different pore sizes or measurement of completely unfiltered samples is possible in theory but must be discussed in advance.

Contact

Dr. Sarah Nettemann