Expertise
Biodiesel and Triglycerides
Detection of sterol glucosides in biodiesel by liquid chromatography-mass spectrometry and nuclear magnetic resonance spectroscopy
Sterol glucosides are one of the the most important sources of precipitation problems in biofuels. The analysis of sterol glucosides in biodiesel and biodiesel filter residues is therefore an essential tool for the investigation of biodiesel problems.
Intertek MSG has developed NMR and LC-MS methods which give a multi-technique approach for a confirmed indentification of the presence of steryl glucoside in a biodiesel sample.
LC-MS analysis
The volatility of steryl glucosides is too low for them to be successfully eluted by GC without derivatisation. They also have very limited sensitivity with conventional HPLC detectors. LC-MS is, therefore, the chromatographic technique of choice for sterol glucoside analysis. The analysis is carried out using a LC-MS TOF analyser which gives the detection of low levels of both steryl glucosides (such as β-sitosteryl glucoside) and esterified steryl glucosides (such as β-sitosteryl glucoside palmitate).
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| The LC-MS chromatogram, below, shows the extracted ion peaks for steryl glucoside in a biodiesel filter residue together with the LC-MS peak for a standard solution of β-sitosteryl glucoside.
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NMR analysis
The advantage of NMR is that it provides a reliable, quantitative and comparatively rapid method for detection of sterols without the need for any sample modification. The initial NMR analysis involves using Sterol standards from which diagnostic 1H NMR peaks are determined. It is now possible to identify Sterol glucosides in various Biodiesel problem samples without chemical modification using these diagnostic NMR peaks.
Advice is available, so make the call +44 (0) 1642 435788 or email MSGenquiry@intertek.com
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