Metalloporphyrin speciation by liquid chromatography and inductively coupled plasma-mass spectrometry

Determination of porphyrins and metalloporphyrins using liquid chromatography-diode array detection and mass spectrometry

A HPLC procedure has been optimized and successfully applied to porphyrins of environmental interest, such as etio and octaethylporphyrins and their VO and Ni compounds. The use of UV-Vis diode array allowed the detection of the analytes within the 5-15 ng/ml range. In order to achieve greater specificity and some structural information, the coupling of liquid chromatography with mass spectrometry was investigated, and the particle beam interface conditions were optimized. Electron impact (EI) spectra, comparable to those reported in the literature were obtained. The entire procedure has been applied to a real marine sediment, previously spiked with porphyrins to resemble oil-contaminated samples. The results pointed out that the method is suitable for such levels of analytes (5-10 microg/ml), allowing their identification and quantification with no need for purification steps.

Separation of metalloporphyrins by capillary electrophoresis with UV detection and inductively coupled plasma mass spectrometric detection

Vitamin B12, cobalt protoporphyrin, manganese protoporphyrin, and zinc protoporphyrin were separated using capillary electrophoresis, and a comparison was made between detection with inductively coupled plasma mass spectrometry (ICP-MS) and UV detection. Absolute limits of detection were slightly better with ICP-MS detection than with UV detection, but for both methods absolute detection limits were in the picogram range. The migration times of the analytes decreased by several minutes when ICP MS detection was employed, and this phenomenon was believed to be a result of a "suction effect" that developed when the CE capillary was interfaced to the ICP-MS nebulizer. However, the resolution between species containing the same metal atom was not altered significantly, and the separation was completed in much less time relative to separations performed with UV detection.

Liquid chromatography-inductively coupled plasma mass spectrometry

The technique of coupling liquid chromatography to inductively plasma mass spectrometry (ICP-MS) is reviewed. A brief introduction to the ICP-MS instrument is given as well as methods to couple the two analytical instruments together. The various types of LC that have been used with ICP-MS detection are discussed and advantages over traditional methods of detection are highlighted, such as the improvements in sensitivity and selectivity. Several applications that have been described in the literature are reviewed. An outlook for the future of LC-ICP-MS, particularly with regard to elemental speciation is given.

Inductively coupled plasma mass spectrometric detection for chromatography and capillary electrophoresis

Inductively coupled plasma mass spectrometry (ICP-MS) is now a well established detection technique for liquid chromatography, gas chromatography, supercritical fluid chromatography and capillary electrophoresis. A review of the literature with particular regard to ICP-MS as a chromatographic and capillary electrophoretic detector is presented. The various modes of chromatography and capillary electrophoresis are discussed and practical descriptions for hyphenating the techniques with the ICP mass spectrometer are given. Sample introduction systems and data acquisition methods are reviewed along with the numerous applications of ICP-MS as a chromatographic detector. In addition, alternative plasma sources, such as the atmospheric and reduced pressure helium microwave-induced plasmas for chromatographic detection are described.