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A Sensitive and Robust Method of Analyzing Endotoxins in Complicated Matrices

Technology #16100n

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FENG Huatao
SU Min
FUNG Fun Man
LI Fong Yau
Managed By
Ms Yong Yoke Ping
Manager (65)66011680
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Tech Offer 16100N Method for Analyzing Endotoxins [PDF]

A Sensitive and Robust Method of Analyzing Endotoxins in Complicated Matrices

FENG Huatao; SU Min; FUNG Fun Man; LI Fong Yau

Department of Chemistry

Industry Problem

One of the most common method of analyzing endotoxins in water is the Limulus Amebocyte Lysate (LAL) assay, which utilizes serum from horseshoe crabs. Although the LAL assay works in simple water matrices such as drinking water and water used for medical applications, it doesn’t work well in complex matrices such as wastewater or water in reservoirs as effects of temperature, pH, ions, and even reagent chemicals can influence the LAL results. Moreover, endotoxins has the ability to form agglutinate or micelles. These micellar structures reduce their reactivity relative to LAL and make LAL results inaccurate to reflect the true concentration of endotoxins. A reliable analytical method for endotoxin analysis will serve as a useful tool in drinking water purification processes and water reclamation plants.

Figure 1: Extraction of Horseshoe crab used in LAL assays (Source: Screenshot from PBS1)


This technology relates to a reliable and robust method to analyze endotoxins levels in water samples in complicated matrices. It comprises of a sample preparation method to extract and enrich endotoxins, from other interference materials, so as to increase the sensitivity of this method.

 Figure 1: CE separation of 13 LPS standards under the optimized conditions

 Figure 2: Determination of LPS in tap and raw effluent before wastewater treatment

 Figure 3: Investigation of detection limit of endotoxin from Klebsiella Pneumonia by ultrapure water dilution. Sample injection time: 10 s.

Value Proposition

  • Sample Enrichment
  • Ability to cope with dilute samples
  • Endotoxin detection in complicated matrices e.g. raw water

Other Potential Applications

  • This technology can be modified so as to extract and capture N-glycans from complicated samples.
  • Application of this technology to other analytes can be explored upon expression of interest.

For more information, contact:

NUS Industry Liaison Office

  :+65 6516 7175



Ref : 16100N

Principal Investigator: Prof. Sam Li


This research is supported by the Singapore National Research Foundation under its Environment & Water Research Programme and administered by PUB, Singapore’s national water agency.