As Dodeca 2E,4E,8Z,10E,Z-tetraenoic acid isobutylamide reference substance occurs as a mixture of two isomers (10E and 10Z) the absolute purity is assigned by quantitative NMR . These show differences in UV absorbance, are poorly resolved in HPLC, and peak areas differ. Isomer composition may also vary between different batches. Thus, batch to batch continuity cannot be proven by HPLC-UV. Even if absolute purity of two batches is identical, the peak areas obtained in HPLC can differ significantly. If the isomer composition of the analyzed sample differs, then additional uncertainty will be introduced. For these reasons we strongly recommend to use this reference standard for qualitative purposes only and to be aware of the analytical challenges. Nonetheless, we provide quantitative data and a certified purity value on the COA. More detailed information will be given on the documents accompanying this reference substance.
For stability reasons this reference substance dodeca 2E,4E,8Z,10E,Z-tetraenoic acid isobutylamide has been dissolved in acetonitrile and is available in portions of 10 mg in approx. 1 mL of acetonitrile only. Therefore, the discount scheme for larger units is not applicable to this reference standard. This reference substance is a mixture of the 10E- and 10Z-isomers.
The substance is a mixture of two isomers, 10E and 10Z, which show differences in UV absorbance, and thus also the peak areas of both isomers differ in HPLC. Furthermore, different batches may vary in their composition of the isomers, which are usually also only poorly resolved by HPLC. A comparison between peak areas of different batches is, therefore, impossible, and batch to batch continuity cannot be proven by HPLC-UV. Keep in mind that - even if the certified absolute purity of different batches is identical, or taken into account in the quantitative calculations - the peak areas obtained in HPLC analysis can differ significantly. Additional uncertainty is introduced if the isomer distribution in the analyzed sample differs from the isomer ratio in this reference substance. For these reasons we strongly recommend to use the reference substance for qualitative purposes only. Please refer to the COA for more details. Packed under nitrogen. Recommended to be stored under inert atmosphere. Avoid exposure to oxygen.
The compound has been dissolved in approx. 1 mL of acetonitrile. The exact weight is given on the label of the vial. In order to produce a stock solution of known concentration please transfer the contents of the vial quantitatively into a volumetric flask by repeated rinsing with excess solvent and then fill to the mark.
soluble in acetonitrile and methanol; slightly soluble in n-hexane
usually a stock item
in styrofoam box together with deep frozen gel packs