Urine strontium

In water and beverages strontium can be measured directly, but food and biological materials require a pretreatment with hydrochloric acid (3 M) and lanthanum chloride [91]. In urine strontium can be determined after dry-ashing and addition of lanthanum [91] or directly after 1 2 dilution with an acidic lanthanum chloride solution [92], The determination of strontium in bone requires special attention because the bone matrix contains high amounts of calcium and phosphate, which can easily interfere with the determination of strontium. Razmilic described a method to isolate strontium from the calcium phosphate matrix by ion exchange chromatography. The pretreated samples then can be analysed by both emission and absorption spectrophotometry measurements without chemical, ionization, or bulk interferences [93,94]. 

System (2) has been described for the assay of corticosteroids (cortisone, hydrocortisone, prednisone, and prednisolone) in urine [141]. Prior to introduction into the GC system, the sample was eluted with 2 1 ethyl acetate-methanol, the extracts evaporated to dryness, and then oxidized with sodium bismuthate. Used in the method was a silanized column (132 cm X 5 mm) containing 2,2-dimethylpropane-l,3-diol adipate (0.65%) supported on celite, and operated at 230°C. The carrier gas was argon, and the detector used strontium 90-ionization. The standard deviation was 3.5 % (based on 47 determinations). 

Kramer, G. H. and Davies, J. M., Isolation of strontium-90, yttrium-90, promethium-147, and cerium-144 from wet ashed urine by calcium oxalate coprecipitation and sequential solvent extraction, Anal. Chem., 54, 1428-1431, 1982. 

Schulten, H. R., Palavinskas, R., and Kiersten, R. (1983). Time-dependent excretion of lithium, sodium, potassium, rubidium, magnesium and strontium in the urine of a multiple sclerosis patient. Biotned. Mass Spectrom. 10, 192-196. 

The analyte was concentrated (enrichment factor 200) but high levels of natural strontium in the separated fraction (of about 1 jxg mF ) meant higher detection limits (80 pg 1 ) due to peak tailing of Sr+ atm/z = 90 and the relatively low abundance sensitivity of ICP-SFMS at a medium mass resolution of 6 x 10 . This detection hmit in the separated fraction corresponded to a detection limit of O.TpgT in the original urine sample. The recovery of °Sr, determined by the described analytical method in spiked urine samples, was in the range 82-86 %. Decreasing the detection hmit for °Sr determination is recommended by the apphcation of a multiple ion collector ICP-MS due to improved abundance sensitivity. The analytical methods described can also be applied for the analysis of other body fluids, such as blood or human milk or for the determination of °Sr in bones. 

Several papers deal with magnesium determination in blood and urine. Willis (WIO) analyzed serum in the air-acetylene flame and found no effect from the presence of sodium, potassium, calcium, or phosphate, but states that an enhancement was seen in serum diluted with water only, probably due to serum proteins. This interference was controlled by addition of strontium or EDTA. Sensitivities were the same in the eoal gas-air and air-acetylene flame, indicating complete atomization of magnesium. In urine (W13) no interference was encountered and determinations were performed on samples directly diluted with water. 

Stable Strontium. All people have small amounts of stable strontium in their bodies, mostly in bone. It can be measured in the blood, hair, feces, or urine. The amount is usually measured by its mass (grams). Measurements in urine can show whether you have been exposed recently to larger-than-normal amounts of strontium. Measurements in hair can reveal whether you were exposed to high amounts of strontium in the past. Most physicians do not test for strontium in their offices, but can collect samples and send them to a special laboratory. Normal x-ray procedures can show changes in bone that may occur from exposure to high amounts of strontium. However, these changes may have other causes (vitamin D deficiency or exposure to an excess of some other trace metal) and the x-ray cannot determine that strontium is involved. 

Radioactive Strontium. If a person has been exposed to radioactive strontium, special tests can be used to measure radioactive strontium in blood, feces, or urine. These tests are most useful when done soon after exposure, since radioactive strontium is quickly incorporated into bone and its release from bone occurs in very small amounts over a period of years. Radioactive strontium can be measured by its mass (in grams) or by its radiation emissions. These emissions, which differ for the various isotopes of strontium, are used to tell the amount of radioactive strontium (in Curies or Bequerels) and the radiation dose in gives to your body (in Sieverts or rem). In a procedure that is similar to being x-rayed, specialized equipment can measure radioactive strontium that has attached to bone. 

Evidence for absorption of inhaled strontium in humans is provided by several cases of accidental exposure of workers to airborne radiostrontium (Navarro and Lopez 1998 Petkau and Pleskach 1972 Rundo and Williams 1961). Although these cases do not provide a complete quantitative description of the absorption of inhaled strontium in humans, they demonstrate clearly that inhaled aerosols of strontium compounds (e.g., SrCl2, SrTi03) can be absorbed, as indicated by the detection of radiostrontium in urine and feces. 

Strontium that has been absorbed from the gastrointestinal tract is excreted primarily in urine and feces. In two dial painters, rates of urinary and fecal excretion of radium approximately 10 years after the exposure were approximately 0.03 and 0.01% of the body burden, respectively (Wenger and Soucas 1975). The urine fecal excretion ratio of 3 that was observed in the radium dial workers is consistent with ratios of 2-4 observed several days to weeks after subjects received an intravenous injection of SrCl2 (Bishop et al. 1960 Blake et al. 1989a, 1989b Newton et al. 1990 Samachson 1966 Snyder et al. 1964 Uchiyama et al. 1973). Thus, urine appears to be the major route of excretion of absorbed strontium. The observation of fecal excretion of radioactive strontium weeks to decades after an oral exposure or over shorter time periods after an intravenous exposure suggests the existence of a mechanism for transfer of absorbed strontium into gastrointestinal tract, either from the bile or directly from the plasma. Evidence for direct secretion of strontium from the plasma into the intestine is provided by studies in animals (see Section 3.5.1). The available information does not address the extent to which biliary excretion may also contribute to fecal excretion of strontium. 

In volunteers who were exposed to dermally applied 85SrCl2 in the left forearm, 85Sr was excreted in urine (fecal excretion was not measured in this study) (Ilyin et al. 1975). Although no other studies were located regarding the excretion of dermally absorbed strontium, it is likely that the excretion would be similar to that absorbed from the oral route, with urinary excretion being approximately 2-3 times greater than fecal excretion (see Section 3.4.4.2). 

Stable strontium is ubiquitous in the diet and can be measured in urine, blood and feces by a number of methods outlined in Section 7.1. After exposure, approximately 99% of the absorbed strontium that is retained is found in bone and connective tissues (Schroeder et al. 1972). Normal background levels of strontium were measured by emission spectrography in cadaver tissue from 168 American subjects (Tipton 1981 Tipton and Cook 1963). Average strontium levels in human tissues expressed as ppm ash were as follows rib bone 110 ppm, vertebra 100 ppm, aorta 33 ppm, ileum 25 ppm, duodenum 11 ppm, lung 8.2 ppm, kidney 5.2, heart 2.6 ppm, liver 1.6 ppm. In a small group of adult males, the mean strontium concentration in plasma was 29pg/L (Sutton et al. 1971b). 

Soluble radioactive strontium can be detected in urine, blood or feces by liquid scintillation counting. Whole body counters (or chest counters for inhalation exposures) can measure internal radioactive strontium deposited in bone following high level exposures (see Section 7.1.1). Children tend to incorporate strontium more homogenously throughout bone than is the case for adults. 

Stable Strontium. Levels of stable strontium can be measured in blood or urine to determine exposures of any duration. Within a few days most of the retained strontium is found in bone, but because of bone remodeling, strontium will be released over time and be detectable in blood and urine. No additional biomarkers of exposure to stable strontium appear to be needed. 

Radioactive Strontium. Exposures to radioactive strontium can be determined readily by measuring levels of radioactivity in blood or urine by liquid scintillation counting techniques. In addition, whole body counters can determine the level of radiostrontium retained in the skeleton. There appears to be no need for additional biomarkers of exposure to radioactive strontium. 

In vitro radioactive strontium analyses are routinely performed in support of a personnel monitoring program, or in cases where the size of an operation does not justify the cost of whole body counter facilities. These analyses are usually done on urine samples, but other types of body materials (e.g., feces or blood) may also be used. Urinalysis is effective for analysis of transportable or soluble strontium. Strontium may also be measured in fecal material using the same methods identified above for urinalyses, except that this matrix requires extensive preparation. 

Argiro G, Atzei G, Boemi S, et al. 1998. A process for the recovery of strontium from the urine of patients injected with 89Sr. Appl Radiat Isot 49(7) 777-778. 

Coob J, Warwick P, Carpenter RC, et al. 1994. Determination of strontium-90 in water and urine samples using ion chromatography. Analyst 119 1759-1764. 

D Haese PC, Van Landeghem GF, Lamberts LV, et al. 1996. Measurement of strontium in serum, urine, bone, and soft tissues by Zeeman atomic absorption spectrometry. Clin Chem 43(1) 121-128. 

Fujita M, Iwanoto J, Kondo M. 1969b. Variation of strontium-calcium observed ratio (urine/diet) in man. Health Phys 16 441-447. 

Hazzard DG. 1969. Percent cesium-134 and strontium-85 in milk, urine, and feces of goats on normal and verxite-containing diets. J Dairy Sci 52(7) 990-994. 

Leeuwenkamp OR, van der Vijgh WJH, Hiisken BCP, et al. 1989. Quantification of strontium in plasma and urine with flameless atomic absorption spectrometry. Clin Chem 35(9) 1911-1914. 

Scasnar V. 1984. Determination of strontium-90 in urine by extraction without ashing. Anal Chem 56 605-608. 

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