Quantitative analysis of electron energy-loss spectra from ultrathin-sectioned biological material. II. The application of bio-standards for quantitative analysis.
Electron energy-loss spectroscopy (EELS) has been used to determine elemental concentrations in biological specimens, consisting of ultrathin-sectioned cells and tissues. Chelex100-based Ca- and Fe Bio-standards are used for elemental quantification to establish iron and calcium concentrations. These Bio-standards, as well as the biological materials, are treated in a standard EM procedure such that 'known' and 'unknown' sites are located in one cross-section. Uncertainties and variabilities present in the equations for calculating the concentration in the 'unknown' site (determined by comparing simplex-fitted EEL spectra from Bio-standards with those from tissue) are outlined in two examples. Using an H+ Bio-standard, the matrix composition of such biological cell material is analysed, leading to values which approach each other closely. Quantitative EELS, using Chelex100-based Bio-standards, is advocated.
Sorber
C W
CW
AEM Unit, Erasmus University Rotterdam, The Netherlands.
Ketelaars
G A
GA
Gelsema
E S
ES
Jongkind
J F
JF
De Bruijn
W C
WC
D000818:Animals; D002118:Calcium / Q000032:analysis; D002129:Calcium Oxalate / Q000032:analysis; D002244:Carbon / Q000032:analysis; D004912:Erythrocytes / Q000737:chemistry / Q000648:ultrastructure*; D005293:Ferritins / Q000032:analysis; D007091:Image Processing, Computer-Assisted; D007501:Iron / Q000032:analysis; D007669:Kidney Calculi / Q000737:chemistry / Q000648:ultrastructure*; D008264:Macrophages / Q000737:chemistry / Q000648:ultrastructure*; D008854:Microscopy, Electron / Q000379:methods*; D051381:Rats; D013057:Spectrum Analysis / Q000379:methods*
D002129:Calcium Oxalate; D002244:Carbon; D005293:Ferritins; D007501:Iron; D002118:Calcium