[The determination of porphyrin carbon isotope composition by gas chromatography-isotope ratio monitoring mass spectrometry technique].
The porphyrin carbon isotope composition can be used to explore the precursor of porphyrin, oil-oil and oil-source rock correction and calculation of paleo P CO2. The conventional method is limited because of its time consuming and large sample size (several mg of individual porphyrin) required. Therefore, it hampers the application of porphyrin carbon isotope composition into the chemistry and geoscience. The present paper describes a quantification method to prepare bis-(tert-butyldimethylsiloxy) silicon (IV) [(TBDMSO)2Si(IV)] porphyrin which is sufficiently volatile at 300 degrees C and can be used for GC-IRMS analysis. The analysis of carbon isotope composition of aetio I as the form of free base, nickel, demetalization derivative, silicon(IV) and (TBDMSO)2Si(IV) have shown that aetio I porphyrin has no obvious isotope fractionation in the whole synthesis procedure for (TBDMSO)2Si(IV) porphyrin. The carbon isotope study on the porphyrin mixtures of aetio I and OEP indicates that isotope exchange between porphyrins during the synthesis of (TBDMSO)2Si(IV) porphyrin is absent. The method can be applied to the determination of porphyrin carbon isotope compositions. The advantages of the method are time saving, less sample size and lower standard deviation.
Yu
Z Q
ZQ
State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China.
Peng
P A
PA
Fu
J M
JM
Sheng
G Y
GY
D002247:Carbon Isotopes / Q000032:analysis*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D011166:Porphyrins / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet
D002247:Carbon Isotopes; D011166:Porphyrins