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A simple method of using an internal standard for X‐ray microanalysis of microdroplets
Author(s) -
Haiyun Xu,
; Marshall
Publication year - 1998
Publication title -
journal of microscopy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.569
H-Index - 111
eISSN - 1365-2818
pISSN - 0022-2720
DOI - 10.1046/j.1365-2818.1998.00319.x
Subject(s) - pipette , microanalysis , calibration , calibration curve , analytical chemistry (journal) , sample preparation , chemistry , internal standard , simple (philosophy) , electron probe microanalysis , elemental analysis , materials science , chromatography , mineralogy , detection limit , physics , philosophy , organic chemistry , quantum mechanics , epistemology , electron microprobe
The use of an introduced internal standard for the X‐ray microanalysis of microdroplets of very small volumes of fluid has hitherto depended on the measurement of equal volumes of sample and standard fluids taken up in a tapered micropipette. It is shown that this difficult procedure can be circumvented by taking up variable volumes of fluids in a constant diameter micropipette. Only the lengths which the fluids occupy in the micropipette need be measured. These parameters are entered into the equation for the thin film model to calculate elemental concentrations. This considerably simplifies the preparation and analysis of microdroplets of biological fluids. Relative elemental sensitivities ( k factors) can be reliably obtained either from thin crystals of binary standards or from calibration curves. It is also shown that rapid air‐drying of microdroplets incorporating PVP results in crystals of acceptable dimensions for analysis.