n-Alkane Profile of Argemone mexicana Leaves

An n-hexane extract of fresh, mature leaves of Argemone mexicana (Papaveraceae), containing thin-layer epicuticular waxes, has been analysed for the first time by TLC, IR and GLC using standard hydrocarbons. Seventeen long-chain alkanes (n-C18 to n-C34) were identified and quantified. Nonacosane (n-C29) was established as the n-alkane with the highest amount, whilst octadecane (n-C18) was the least abundant component of the extracted wax fraction. The carbon preference index (CPI) calculated for the hydrocarbon sample with the chain lengths between C18 and C34 was 1.2469, showing an odd to even carbon number predominance.

A Multiparameter Oil Pollution Source Identification System

ABSTRACT The key parameters of carbon and sulfur isotopie composition, total sulfur, nitrogen, vanadium, nickel and normal paraffin odd-even carbon number predominance were measured on the 600°+F residue, which simulates a weathered sample of crude oil. The variation of these parameters among 80 crude oils representative of worldwide sources of water-transported oils forms the basis of an identification system. The parameter range was carbon isotopic composition, −22 to −30 per mil; sulfur isotopie composition, −14 to +20 per mil; total sulfur 0.05 to 6.0 weight per cent; nitrogen 0.02 to 0.73 weight per cent; vanadium 0.2 to 466 wppm; nickel 0.2 to 128 wppm; and odd-even carbon number predominance 0.8 to 1.3. An unknown oil is identified by comparison of these paramters with those in a data library or from suspected sources. A computer “look-up” system was demonstrated to match any one of the 80 crude oils with an unknown. The identification potential is strengthened by addition of the diagnostic parameters of percentage saturates, aromatics and asphaltics as measured by silica gel chromatography and the gas-liquid chromatography hydrocarbon and sulfur profiles (“fingerprints”).