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E. Rosenberg:
"Quantitative Determination of `Organic Germanium´ in Nutritional Supplementations";
Poster: TraceSpec2009 - 12th Workshop on Progress in Analytical Methodologies for Trace Metal Speciation, Mainz; 15.09.2009 - 18.09.2009.

Organic germanium compounds, and in particular bis-carboxyethyl germanium sesquioxide
(= commonly also named germanium sesquioxide or Ge-132), has for long been under
discussion as a nutritional supplement and even a therapeutic agent cancer,
immunodeficiency, and other infectious diseases (1). While its beneficial effect for human
health has not been demonstrated in a convincing way yet, it continues, however, to be sold
via the internet in formulations of different form, e.g. as pure compound, as solution or as
tablets. While the beneficial effect of germanium supplementations to the human diet may be
arguable, and at least no adverse effects could be observed with the intake of this drug even
at higher dosages and for extended periods of time, this is not true for the inorganic forms of
germanium, notably germanium oxide (GeO2). Germanium oxide exhibits pronounced renal
toxicity, and has been reported to have led to a number of casualties in the case of regular
uptake (2). This clearly points out the need for the speciation of germanium and its (organic)
compounds.
Different analytical approaches have been reported in the literature. These are based on ion
chromatography (with optical emission (3) or ICP-MS detection (4)), or on the differential
determination of the elemental and organic bound form after digestion (5). None of these
actually confirms the presence of germanium sesquioxide rather than by the element specific
response of the detector, and the agreement of the retention time with the one of authentic
standards.
We present here a novel approach for the determination of inorganic germanium and
germanium sesquioxide, based on liquid chromatographic separation on an ion exchange
column (Phenomenex Rezex RHM) with ESI-MS detection. While elemental germanium is
unretained on this particular column, Ge sesquioxide can be detected in the form of its
monovalent anion, whereby the exact mass of the detected anion, as well as its
fragmentation pattern confirm the identity of the Ge sesquioxide.
It appears to be important to analyse the samples containing Ge sesquioxide promptly after
preparation, as the drug tends to hydrolyse to the monomeric subunit, and this can further
condense to more complex systems containing two, three or more Ge atoms (6).
(1) I. Omae, Applications of Organometallic Compounds, John Wiley & Sons, Chichester,
(1999) 165-184.
(2) S.-H. Tao, P. M. Bolger, Regulatory Toxicol Pharmacol 25 (1997) 211-219.
(3) A. Padró, R. Rubio, G. Rauret, Fresenius J. Anal. Chem. 351 (1995) 449-453.
(4) P. Krystek and R. Ritsema, J. Trace Elem. Med. Biol. 18 (2004) 9-16.
(5) D.-Q. Zhang Z.-M. Ni, Anal. Chim. Acta 330 (1996) 53-58.
(6) R. Jirasko, E. Rosenberg, M. Holcapek, Intern. J. Mass Spectrom. 280 (2009) 198-203