Rapid identification of Mg-chelated chlorins by on-line high performance liquid chromatography/atmospheric pressure chemical ionization mass spectrometry

✍ Scribed by Ludovica Verzegnassi; Catherine Riffé-Chalard; Fazil O. Gülaçar

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 69 KB
• Volume: 14
• Category: Article
• ISSN: 0951-4198
• DOI: 10.1002/(sici)1097-0231(20000415)14:7<590::aid-rcm917>3.0.co;2-p

✦ Synopsis

On-line high performance liquid chromatography/atmospheric pressure chemical ionization mass spectrometry (HPLC/APCI-MS) has been applied to the identification of a number of tetrapyrrolic pigments as well as several magnesium-free analogs. Mass spectra, acquired both in positive () and negative (À) ionization mode, allow not only the determination of the structural features of the pigments, but also a very easy differentiation of the Mg-chelated pigments from the free bases. In the positive ionization mode, all pigments show mainly a [M H] ion and a [M H À C 20 H 38 ] fragment ion corresponding to the loss of the phytyl chain via a hydrogen rearrangement. In the negative ionization mode, on the other hand, although all pigments give an abundant molecular anion [M] ÀÁ , only the Mg-chelated chlorin spectra show a prominent fragment [M À C 20 H 39 ] À produced by a formal loss of the phytyl radical.