Comparison of methods of external and internal standard for GC determination of docosahexaenoic acid was written by Ivanova, Stefka Achkova;Tsvetkova, Dobrina Doncheva;Obreshkova, Danka Petrova. And the article was included in Bulletin of Pharmaceutical Research in 2018.SDS of cas: 1731-94-8 The following contents are mentioned in the article:
Present study includes the comparison of methods of external and internal standard for the estimation of parameters like linearity and precision in gas chromatog. anal. of docosahexaenoic acid (DHA) with flame ionization detector at temperature 140°C – 280°C and using hydrogen as gas carrier. Linear dependence of the ratio of area of methylated DHA/area of Me nonadecanoate (internal standard) to the DHA concentration was obtained. There was no observed difference between the correlation coefficients for two methods (R2 = 0.9928). From the exptl. results, it is obvious that related standard deviation (RSD) for internal standard method is more than RSD for external standard method, which demonstrates that nonadecanoic acid is not a suitable internal standard The external standard method allows achievement of good linearity and precision and is appropriate for identification and determination of DHA and fatty acids in food supplements. This study involved multiple reactions and reactants, such as Methyl nonadecanoate (cas: 1731-94-8SDS of cas: 1731-94-8).
Methyl nonadecanoate (cas: 1731-94-8) belongs to esters. Esters are widespread in nature and are widely used in industry. In nature, fats are in general triesters derived from glycerol and fatty acids. Esters are responsible for the aroma of many fruits. Esters are more polar than ethers but less polar than alcohols. They participate in hydrogen bonds as hydrogen-bond acceptors, but cannot act as hydrogen-bond donors, unlike their parent alcohols. This ability to participate in hydrogen bonding confers some water-solubility.SDS of cas: 1731-94-8
Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics