Thermotropic phase transitions of pure lipids in excess water

Thermotropic phase transitions of pure lipids in excess water 

The DSC instrumentation needed for studies of very dilute lipid suspensions are so-called high-sensitivity DSC-instruments, mainly of the adiabatic type, with cell volumes of usually 0.5 - 1.5 inL. The lipid concentration needed for these instruments is in the range of 0.1 - 10 mg/mL, depending on the width of the en-dothenns. The reader is referred to Volume I of this handbook for instrumental details. 

The cell volume of this instrument is 0.5 mL. The sample was prepared at a concentration of 1.82 mM and then diluted and repeatedly re-scanned. For a check of the instnimental sensitivity we perfonned two tests. Firstly, we set the heating rate to bO C/h and ran the instniment in the passive mode . This leads to a broadening of the transition but improved sensitivity. Secondly, we increased the feedback to the fastest response but decreased the heating rate to 30°C/li to reproduce more accurately the very sharp transition of these phospholipids. The sharpness of the transition is now well resolved, but the instnimental noise is somewhat increased. The recently found sub-main transition is clearly resolved as a small additional peak at ca. 53.8°C [22]. The instnimental sensitivity is such 

Influence of headgnmp structure and hydrocarbon chain length 

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