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Ultratrace analysis in biological matrices

Many trace elements play important roles for the regulation of metabolic processes as cofactors of proteins. The concentrations of those elements are often up- or downregulated during diseases in the affected tissue, because they are involved in fundamental processes, like oxygen transportation and storage or the energy metabolism. Also chronically reduced or enhanced concentrations possess extensive influence on the health status of the organism and can cause various diseases. Thus iron deficiency could be triggering heart diseases.

The concentration of most of these relevant elements in animal and human tissue is found to be very low in the µg/g-region or below. In addition, often only little sample masses are available (100 mg or below) to measure these concentrations. Thus analytical methods have to be used which allow for determination of mass fractions in samples in the ppb and ppt region. One has also to be aware of contamination risks from chemicals, lab equipment and the analytical technique, even when working under clean room conditions.

In our work ICP-OES or ICP-MS have been used after digestion in dependence on the concentration level relevant in the samples. Acids and water were subboiled, all labware was cleaned following special procedures, measurements were performed in the clean room. Under these conditions reproducible results could be obtained in the pg/g region with variation coefficients of 1-3 % and LOQs below ng/kg. Most relevant contamination problems were caused by the polymer labware (background values even for PFA not negligible). In table 1 background values in different organs of rats are summarized for selected trace elements, which are currently under investigation to help explain the development of certain diseases.

Table 1. Background values for selected trace elements and organs in rats (n = 10).

Element

Blood

Liver

Kidney

 

 

ω

±

u(ω)

ω

±

u(ω)

ω

±

u(ω)

Cu

ppmw

1.1

±

0.1

4.1

±

0.2

6.9

±

1.6

Zn

6.7

±

0.3

26

±

1

22

±

1

Ni

ppbw

12

±

4

Not determined

86

±

19

Y

pptw

47

±

11

165

±

42

285

±

112

Ag

< 574

< 450

317

±

167

La

43

±

3

130

±

18

43

±

22

Ce

51

±

11

200

±

24

59

±

13

Nd

91

±

5

149

±

21

55

±

15

Gd

54

±

11

94

±

9

50

±

27

Dy

9.3

±

0.9

39

±

11

17

±

7

 

Publications

  • U. Assmann, Spurenbestimmung von Fluorid in biologischen Matrices, Diplomarbeit, 2006, Leibniz Universität Hannover
  • M. Lange, Elementspurenanalytik in Leber und Knochen von Kaninchen, Diplomarbeit, 2005, Leibniz Universität Hannover
  • S. Haddad, Y. Wang, B. Galy, M. Korf-Klingebiel, V. Hirsch, A. M. Baru, F. Rostami, M. R. Reboll, J. Heineke, U. Flögel, S. Groos, A. Renner, K. Toischer, F. Zimmermann, S. Engeli, J. Jordan, J. Bauersachs, M. W. Hentze,  K. C. Wollert, T. Kempf, Iron-regulatory proteins secure iron availability in cardiomyocytes to prevent heart failure, European Heart Journal (2016), doi:10.1093/eurheartj/ehw333

Cooperations partners

  • Prof. T. Kempf, Medizinische Hochschule Hannover
  • Dr. J. Reifenrath, Medizinische Hochschule Hannover
  • Prof. F. Witte, Charité Berlin