 Detailed application note NDELA in cosmetics (pdf)
Cosmetics often show high concentrations of the carcinogenic compound N-nitrosodiethanolamine (NDELA).
For analysis several methods can be chosen, e.g. GC-TEA, HPLC-MS/MS or HPLC with photolysis and post-column derivatisation. The latter method features high specificity, minimizes the risk of measuring artefacts and allows precise quantification. That's why it is proposed by the Technical Committee for Cosmetics of the International Organization for Standardization as preferred method.
Method of choice: ISO/DIS 10130
This procedure is described as ISO/DIS 10130. NDELA is first of all chromatographically separated from the matrix, the n-nitroso-bond is photochemically cracked at 254 nm using a UV derivatisation device. In a Griess reaction the produced nitrite is then converted into strongly coloured azo dye, which can be detected at 540 nm.
The right systems for your NDELA analysis
For both the online photolysis and post-column derivatisation LCTech offers suitable systems.
The UVE is a high-performance and professional and nevertheless extremely well-prized device for photochemical cracking of n-nitroso-bonds. The subsequent post-column derivatisation by Griess reagent is reliably done with a one-stage PINNACLE PCX System of PICKERING Laboratories. Both systems can at once be integrated into every existing HPLC system and transform your device to a NDELA analyzer.
The very special advantage: Within few minutes the PINNACLE PCX can be changed to a formaldehyde analyzer.
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