Iron in blood

In thermal ionization mass spectrometry (TI-MS), solid, inorganic compounds may be volatilized from a heated surface. TI-MS is the most precise method for the measurement of isotopic ratios of minerals and has been used to analyze 58pe in fecal samples collected from a human study (H). The major drawbacks of this technique are the costly instrument and the slow sample through-put. Conventional mass spectrometry produces ions by electron bombardment of the vapor of volatile compoimds. This is called electron-impact ionization mass spectrometry (EI-MS). Analysis of iron by EI-MS requires derivitization to volatile forms before introduction into the mass spectrometer. A method has been developed for the synthesis of volatile iron-acetylacetone chelates from iron in blood serxm (1 ). A tetraphenylporphyrin chelate has also been synthesized and used in an absorption study in which 54pe and 57pe were given orally (16). 

R2. Ramsay, W. N. M., The determination of iron in blood plasma or serum. Clin. Chim. Acta 2, 214-220 (1957). 

The bathophenanthroline method was used for determining iron in blood plasma [157], in plant materials [158], in waters [159], in niobium, tantalum, molybdenum, and tungsten [42,160], in molybdenum compounds [161], in cobalt [162], in cadmium and cadmium telluride [5], platinum [163], synthetic rubies and sapphires [164], silicon tetrachloride [165], and in boiler water [166]. 

Iron salts restored skin color, iron in blood, Fe, a nutrient, hemoglobin, 0.35% Fe... 

Cholak et al. (C5) determined 0.05-20 /xg of lead in biological materials by extraction with APCD and MIBK at pH 8.5. Potassium cyanide was added to mask the effects of iron, zinc, and copper. Only bismuth and cadmium were found to interfere under these eonditions. Mishima et al. (M4) deproteinized 5 ml of blood with 10 ml of 5% TCA and extracted the lead with I ml of 1% APCD and 5 ml of MIBK. Marumo et al. (M2) overcame a reported interference from greater than 220 /xg iron in blood by extracting the iron with cupferron into MIBK prior to extraction of the lead with APCD. 

Maohata and Binder (Ml) reported that, with a graphite atomizer, matrix effects caused by iron in blood caused calibration curves to be rather flat (nonlinear) and results to be imprecise. These matrix effects were avoided by the addition of lanthanum salts. 

Transport function Numerous small molecules and ions are transported effectively through the body only after binding to proteins. For example, fatty acids are carried between fat (adipose) tissue and other tissues or organs by serum albumin, a blood protein. Hemoglobin, a well-known example, carries oxygen from the lungs to other body tissues, and transferrin is a carrier of iron in blood plasma. 

The second (a priori) approach is exemplified by determination of Kg for vanadium concentration in a certified reference material consisting of orchard leaves (Ingamells 1974). Application of an analogous approach to calculation of Kg for determination of iron in blood (Esbensen 2004) showed that, under a plausible set of assumptions. Kg is about 5 x 10 g therefore, even with the smallest samples of 5-10 mg used for determination of iron in blood, the contribution from sampling (Equation [8.97]) to the overall uncertainty of the result is negligible relative to the analytical uncertainty of iron determination ( 2-3%). 

Storage protein that bind iron in blood... 

Transport protein that binds iron in blood Condition in which blood vessels respond to stimuli Dilates blood vessels causing decrease in blood pressure Constricts blood vessels causing increase in blood pressure A closed membrane shell, derived either physiologically (bndding) or mechanically (by sonication)... 

Benkhedda, K., Chen, H., Dabeka, R., and Cockell, K. (2008) Isotope ratio measurements of iron in blood samples by multi-collector ICP-MS to support nutritional investigations in humans. Biol. Trace Elem. Res., 122, 179-192. 

---