Elemental analysis of whole blood using proton-induced X-ray emmission.
A technique for the analysis of trace elements in whole blood was developed using proton-induced x-ray emission. Samples of 0.1 ml whole blood from humans and mice were dried, weighed, and then ashed in a plasma asher. Targets were prepared by placing drops made from the ash and a 100-ppM Pd solution onto Formvar backings. The samples were irradiated with 2.25-MeV protons, and the x-rays analyzed in a nondispersive x-ray detector. The elements Fe, Cu, Zn, Se, and Rb were detected with a precision of 7, 18, 7, 50, and 19%, respectively, in human whole blood. The precision of the technique was determined by statistical analyses of two different sets of 27 samples. The system was found to be linear for variations in elemental concentration. The accuracy for deterrmination of Zn was found to be within 10% by comparison to atomic absorption spectrometry.
A target chamber for charged particle induced x-ray fluorescence studies
Abstract A target chamber is described which combines extremely low acquisition cost with precision adjustment and exchange of as many as 26 targets without breaking chamber vacuum. The chamber was designed for particle induced x-ray fluorescence studies and allows great detection efficiency due to its small target-detector distance. To expand its usefulness, the chamber can also hold one solid state surface barrier detector at 90° with respect to the beam. This feature allows charged particle studies as well as particle-gamma ray coincidence measurements.
Characterization of Aqueous Dispersions and Gels Made of Sodium Caseinate and Basil Seed Gum: Phase Behavior, Rheology, and Microstructure
The interactions between sodium caseinate (NaCas) and basil seed gum (BSG) in the presence of calcium chloride (CaCl 2 ) were investigated. The phase behavior of the mixed aqueous dispersions and their gels revealed a homogeneous mixture, obtained at the higher concentrations of both CaCl 2 and BSG. The Herschel-Bulkley model sufficiently fitted the flow behavior of the mixture solution data. Apparent viscosity increased significantly ( p  < 0.05) by increasing the concentration of BSG, where the addition of CaCl 2 had no significant effect on the viscosity of the samples ( p  > 0.05). Furthermore, there was an increase in thixotropy due to the higher concentrations of BSG and CaCl 2 . Based on the frequency sweep test, at the low frequencies, a more gel-like behavior was observed in the case of the higher concentrations of either BSG or CaCl 2 . The rheological and SEM data suggested that the stronger structure of NaCas-BSG gel in the presence of the higher concentrations of CaCl 2 was related to the induction of complex formation between the two biopolymers.