Species-unspecific ICP-IDMS

Internal standard 2-ethylthiopliene for mass flow calibration 

4-dibenzothiophene 8 = 2,4,6-trimethyldibenzothiophene. Reproduced with permission from [101], 

Protein Analysis Quantification of proteins is required in many scientific fields, such as clinical chemistry and biochemistry. Various isotope dilution strategies, relying on the use of compounds enriched in H, or 0, have been used 

The first protein quantification based on sulfur monitoring and species-unspecific isotope dilution was carried out by Schaumloffel et al. using a CE unit coupled to a sector field mass spectrometer operated at a mass resolution of 3000 and aimed at analyzing metallothionein fractions of a rabbit liver [110]. 

By analyzing a solution of three standard proteins (lysozyme, ovalbumin, and bovine serum albumin), and also two certified protein reference materials (BCR CRM 393 human apolipoprotein A-1 and BCR CRM 486 a-fetoprotein), the accuracy but also possible limitations of absolute protein quantification via species-unspecific isotope dilution were demonstrated. A micro-HPLC system coupled to a sector field mass spectrometer, operated at a mass resolution of 

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Figure 8.19 Species-unspecific GC-ICP-IDMS set-up for the determination of volatile sulfur species in petroleum products [101],...

Figure 8.20 Sulfur mass flow chromatogram of gas oil reference material BCR CRM 107 obtained by species-unspecific CC-ICP-IDMS. Major peaks identified by EI-MS-MS ...

Figure 8.24 Species-unspecific CE-ICP-IDMS electropherograms of measured sulfur isotope intensities (a) calculated sulfur isotope ratios (b) and mass flows (c) of metallothioneins from a rabbit liver as well as the corresponding mass flow electropherograms of Cd and Zn (d). Reproduced with permission from [108].

Figure 8.25 Sulfur mass flow chromatogram for a protein standard solution as obtained by species-unspecific micro-HPLC—ICP-IDMS and conversion into the amounts of the separated proteins based on the known number of sulfur atoms per protein molecule. Reproduced with permission from [111],...

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