A-TEEM for Organics (CDOM) Water Research

<< View all A-TEEM Spectroscopy Applications

A-TEEM is HORIBA’s proprietary fluorescence spectroscopy technology that simultaneously acquires, Absorbance, Transmission, and fluorescence Excitation and Emission Matrix measurements, correcting for the inner filter effect on the fly.

We have successfully deployed A-TEEM in wastewater treatment facilities, sometimes inline, providing a faster, less costly, and easier way to determine colored dissolved organic matter. The information is used to inform the introduction of additives to neutralize these substances at the treatment plant and monitor the end effect of the process.

A-TEEM in water research is becoming a popular way to characterize water samples both in the lab and in the field to determine its components and profile. The easy sample preparation for the technique allows researchers flexibility to perform sampling in remote locations.

A-TEEM for Water

water analysis

Learn what A-TEEM Spectroscopy can do for water analysis.

Application Notes

Read the application notes created by our applications scientists using A-TEEM Molecular Fingerprinting.


Our eBooks serve as a comprehensive survey of each application of A-TEEM. For water analysis, we present scientific papers, case studies, and videos to better inform you of various applications in this category.

Webinars and Videos

Watch our on-demand water analysis webinars and videos to gain a better foothold on current research and emerging techniques.

Case Studies

Read our articles on water from the Science in Action series of case studies examining a variety of applications for water analysis in the real world.

CDOM Water Research Products

aqualog for water

Find out which HORIBA products incorporate A-TEEM Spectroscopy.

Water Analysis with A-TEEM

The A-TEEM technique was first introduced with the invention of the HORIBA Aqualog spectrometer in 2010. It was initially designed as a more accurate, sensitive, and faster spectroscopy solution for water quality analysis, specifically for the study of chromophoric dissolved organic matter, also called CDOM.

Dissolved organic matter includes amino acids, humic acids, fulvic acids, and other examples of decayed matter in natural water sources, or disinfection byproducts of water treatment processes. Prior to the introduction of the Aqualog, scientists were using traditional scanning spectrofluorometers for CDOM studies. These are slow and do not provide concentration-independent fluorescence EEM fingerprints.

Today, the HORIBA Aqualog is the gold standard for environmental water research, not just for CDOM but for many other species. Aqualog is also being used in water treatment plants around the world as a simple, fast, early warning monitor and to save money by facilitating chemical treatment optimization.


Common fluorescent compounds in water include humic acids, fulvic acids, and amino acids (waste water) which can be studied during various treatment processes, by PARAFAC analysis of the A-TEEM fingerprint. Acquired with Aqualog.

Common fluorescent compounds in water include humic acids, fulvic acids, and amino acids (wastewater). These can be studied during various treatment processes, by PARAFAC analysis of the A-TEEM fingerprint, acquired with Aqualog.

Most components of CDOM have broad overlapping fluorescence excitation and emission spectra in the UV and visible range. Many sample measurements are used to create a model and then chemometrics software is used to get scores of each component in an individual sample. The unique thing about a fluorescence A-TEEM is that it can correct for the inner filter effect. It can be used as a precise molecular fingerprint. Changes in the emission spectrum, the excitation spectrum, or both can be tracked easily using this 3D fluorescence method for water analysis.

Aqualog A-TEEM at Environmental Research Labs

The CCD-equipped Aqualog A-TEEM spectrometer is a much faster and accurate spectrometer for colored dissolved organic matter (CDOM), and much more effective than a scanning PMT fluorometer for EEMs. The Aqualog is used in some of the most prestigious water research labs, and remote locations, to study a variety of important research topics.

Hot Environmental Research Topics for Color Dissolved Organic Matter (CDOM) and its derivatives DOM, and NOM:

Aqualog A-TEEM at Drinking Water Treatment Plants

Aqualog at drinking water treatment plant diagram

Aqualog is used at drinking water treatment plants to monitor and track key water parameters from three different sources: The raw water coming into the plant; the settled water inside the plant after sedimentation; and the finished water that goes into the drinking supply. Key parameters include the following:

  • THM Species
  • DOC
  • SUVA
  • A254
  • Aromaticity Index


To learn more about how A-TEEM molecular fingerprinting can help you with your application, email us at a-teem.us(at)horiba.com

Application Notes

A-TEEM and the Aqualog have been used for many water applications, from environmental studies to drinking water. Use the filters below to find the application most suited for your needs.


Download the Water Treatment eBook and learn the nuances and advances of studying water treatment using A-TEEM.

Webinars and Videos

Watch ondemand webinars and videos and learn how A-TEEM spectroscopy can speed up your water analysis needs.

Life in the Arctic with the Aqualog

Life in the Arctic with the Aqualog was created entirely by our customer who wanted to record her experience transitioning from a scanning fluorometer to the Aqualog for water research. She is solely responsible for its content.

Case Studies

Read all about water quality analysis and the A-TEEM spectroscopy technique. Learn how researches are using the Aqualog in their labs. 


Aqualog - Environmental Water Research Analyzer
Aqualog - Environmental Water Research Analyzer

The Gold Standard for Water CDOM Research

Aqualog - Water Treatment Plant Analyzer
Aqualog - Water Treatment Plant Analyzer

Automated Organic Analysis & Early Warning Sentinel

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