Rapid analytical method of 90Sr in urine sample: Rapid separation of Sr by phosphate co-precipitation and extraction chromatography, followed by determination by triple quadrupole inductively coupled plasma mass spectrometry (ICP-MS/MS).

A rapid analytical method for determining 90Sr in urine samples (1-2 L) was developed to assess the internal exposure of workers in a radiological emergency. Strontium in a urine sample was rapidly separated by phosphate co-precipitation, followed by extraction chromatography, and the 90Sr activity was determined by triple quadrupole inductively coupled plasma mass spectrometry (ICP-MS/MS). Measurement in the MS/MS mode with an O2 reaction gas flow rate 1 mL min-1 showed no tailing of 88Sr at m/z = 90 up to 50 mg L-1 Sr. The interferences of Ge, Se and Zr at m/z = 90 were successfully removed by phosphate co-precipitation, followed by extraction chromatography with a tandem column of Pre-filter, TRU and Sr resin. This analytical method was validated by the results of the analyses of synthetic urine samples (1.2-1.6 L) containing a known amount of 90Sr along with 1 mg of each of Ge, Se, Sr and Zr. The turnaround time for Sr purification from the urine sample and the 90Sr measurement by ICP-MS/MS was about 10 h. The detection limit of 90Sr was approximately 1 Bq per urine sample, which was lower than 15 Bq per urine after a day of intake giving 5 mSv of unplanned exposure of worker limited by Nuclear Regulation Authority of Japan.

Rapid procedure for actinides and 90Sr analysis in emergency urine spot samples applied in the GHSI-RNWG emergency intercomparison exercise.

A rapid radiochemical separation method for quantification of 90Sr, plutonium, americium, curium, uranium and thorium isotopes in urine spot samples has been developed. The validation and suitability of the method has been tested in the emergency intercomparison exercise organised by the Global Health Security Initiative/Radio-Nuclear Threats Working Group. Excellent results were obtained with bias of -0.07 (239Pu) and -0.11 (90Sr). CIEMAT Laboratory also fulfilled the established reporting schedule and submitted the results within 72 hours, as required.

Determination of 89Sr and 90Sr in fresh cow milk and raw urine using crystalline synthetic tunnel manganese oxides and layered metal sulfides.

89Sr and 90Sr are both fission products of high radiotoxicity, which can be released in significant amounts in the event of a nuclear accident. Radiostrontium isotopes will follow calcium all along the food chain and, after ingestion, accumulate in the bones. Therefore, it is imperative to be able to determine 89Sr and 90Sr in raw milk samples in case of an accidental situation to evaluate the dose given by both radionuclides to the population. Several methods exist for conducting 89Sr and 90Sr determination. However, most of them use at least one chromatographic step to purify strontium. This, unfortunately, increases the analytical time before the results can be released to the authorities. In addition, they often use liquid scintillation counting to determine the 89Sr and 90Sr activities, a method which can handle only one sample at a time. Here we propose using synthetic tunnel manganese oxides such as cryptomelane and todorokite and layered metal sulfides to selectively extract strontium from fresh milk and raw urine in a batch sorption method. We found that the method is very quick and yields very pure sources of (radio)-strontium, which can be counted in a proportional counter. Data (counts per minute) from the counter were fitted to a mathematical expression enabling the simultaneous determination of 89Sr and 90Sr. Because a proportional counter often has several drawers, it is typically possible to measure up to 16 samples at a time. Since cryptomelane is a binding phase easily synthesized in a large quantity, we anticipate that this technique could be an interesting alternative to conventional solid phase extraction chromatography methods.

Emergency Radiobioassay Method for Determination of 9°Sr and ²²6Ra in a Spot Urine Sample.

A new radiobioassay method has been developed for simultaneous determination of (90)Sr and (226)Ra in a spot urine sample. The method is based on a matrix removal procedure to purify the target radionuclides from a urine sample followed by an automated high performance ion chromatographic (HPIC) separation of (90)Sr and (226)Ra and offline radiometric detection by liquid scintillation counting (LSC). A Sr-resin extraction chromatographic cartridge was used for matrix removal and purification of (90)Sr and (226)Ra from a urine sample prior to its introduction to the HPIC system. The HPIC separation was carried out through cation exchange chromatography using methanesulfonic acid (75 mM) as the mobile phase at 0.25 mL/min flow rate. The performance criteria of the method was evaluated against the American National Standard Institute ANSI/HPS N13.30-2011 standard for the root mean squared error (RMSE) of relative bias (Br) and relative precision (SB) at two different spiked activity levels. The RMSE of Br and SB for (90)Sr and (226)Ra were found to be satisfactory (≤0.25). The minimum detectable activity (MDA) of the method for (90)Sr and (226)Ra are 2 Bq/L and 0.2 Bq/L, respectively. The MDA values are at least 1/10th of the concentrations of (90)Sr (190 Bq/L) and (226)Ra (2 Bq/L) excreted in urine on the third day following an acute exposure (inhalation) that would lead to an effective dose of 0.1 Sv in the first year. The sample turnaround time is less than 8 h for simultaneous determination of (90)Sr and (226)Ra.

[Interest and limits of inductively coupled plasma mass spectrometry (ICP-MS) for urinary diagnosis of radionuclide internal contamination]. / Intérêt et limites du couplage plasma induit par haute fréquence - spectrométrie de masse (ICP-MS) pour le diagnostic urinaire d'une contamination interne par un radionucléide.

After a review of radiometric reference methods used in radiotoxicology, analytical performance of inductively coupled plasma mass spectrometry (ICP-MS) for the workplace urinary diagnosis of internal contamination by radionuclides are evaluated. A literature review (covering the period from 2000 to 2012) is performed to identify the different applications of ICP-MS in radiotoxicology for urine analysis. The limits of detection are compared to the recommendations of the International commission on radiological protection (ICRP 78: "Individual monitoring for internal exposure of workers"). Except one publication describing the determination of strontium-90 (ß emitter), all methods using ICP-MS reported in the literature concern actinides (α emitters). For radionuclides with a radioactive period higher than 10(4) years, limits of detection are most often in compliance with ICRP publication 78 and frequently lower than radiometric methods. ICP-MS allows the specific determination of plutonium-239 + 240 isotopes which cannot be discriminated by α spectrometry. High resolution ICP-MS can also measure uranium isotopic ratios in urine for total uranium concentrations lower than 20 ng/L. The interest of ICP-MS in radiotoxicology concerns essentially the urinary measurement of long radioactive period actinides, particularly for uranium isotope ratio determination and 239 and 240 plutonium isotopes discrimination. Radiometric methods remain the most efficient for the majority of other radionuclides.

Determination of 90Sr-90Y activity in urine samples by using Cherenkov counting.

Cherenkov counting of the (90)Sr-(90)Y pure beta emitters in aqueous samples is an attractive method; but color quenching correction is needed, this being especially significant for urine which is characterized by a strong coloration. A quench correction method based on the external source of some liquid scintillation systems (named ESAR-External Source Area Ratio) was proposed for aqueous solutions. In the present work, the application of the ESAR method for determination of (90)Sr-(90)Y in human urine samples is described.

Novel tandem column method for the rapid isolation of radiostrontium from human urine.

A method has been developed for the isolation of strontium from human urine for subsequent determination in sample volumes as low as 5-20 mL. This method involves the acidification of the sample using methanesulfonic acid and its decolorization using charcoal, treatment of the filtrate with Diphonix(®) resin, and subsequent concentration of strontium on Sr resin. Data from retention model simulations provided the initial conditions which were then optimized by actual column separations. Diphonix(®) resin was shown to be effective at removing alkali metal ions from the urine matrix under conditions that retain higher valence ions. The suggested processing method provides 99% recovery of Sr(2+), a concentration factor of 50, and an expected per sample processing time of less than 1 h.

Preliminary studies of an 18-crown-6 ether modified magnetic cation exchange polymer in rapid (90)Sr bioassay.

A cation exchange polymer resin embedded with magnetic nanoparticles and modified with crown ether was developed for urinalysis to rapidly monitor levels of (90)Sr exposure in humans who have been involved in a nuclear event. Invention of the resin matrix of 2-acrylamido-2-methyl-1-propanesulfonic acid cross-linked with divinylbenzene incorporated a Sr(2+) chelating agent, di-tert-butyl-cyclohexano-18-crown-6 through surface immobilization using a molecular modifier 1-octanol. The performance of these magnetic cation exchange resin particles was investigated by separating (90)Sr in the presence of (90)Y progeny. Masking agents and precipitants were examined to ascertain that sodium hydroxide at pH 7.5 was capable of selectively removing 89 ± 2% (90)Y before subsequent (90)Sr uptake. Preliminary investigations in rapid urinalysis were successful in isolating 83 ± 2% (90)Sr when pH was optimized to 9, with a sample turnover time <2 h, which is promising for radiological emergencies.

Selectivity of 90Sr urine bioassay technique over 241Am, 238/239PU, 210PO, 137CS and 60CO.

The selectivity of a rapid (90)Sr bioassay technique over (241)Am, (238/239)Pu, (210)Po, (137)Cs and (60)Co has been investigated. Similar to (90)Sr, these radionuclides are likely to be used in radiological dispersive devices. The purpose of this study was to demonstrate the degree to which the (90)Sr bioassay technique is free from interference by these radionuclides if present in a urine matrix. The interfering radionuclides were removed (from (90)Sr) by their retention on an anion exchange column. While, recovery of the target radionuclide ((90)Sr) was found to be >or= 90 %, contributions from (241)Am, (242)Pu and (208)Po were found to be

A rapid bioassay method for the determination of 90Sr in human urine sample.

A rapid bioassay method has been developed for the determination of (90)Sr in human urine samples. The method is based on on-cartridge decolourisation of urine sample, separation of (90)Y from (90)Sr on an anion exchange resin column and by determination of (90)Sr using a liquid scintillation analyser (LSA). Separation of (90)Y from (90)Sr was achieved through selective complexation of yttrium with phosphate and subsequent retention of the anionic yttrium phosphate species on anion exchange resin. A total recovery of 97 +/- 2 % was obtained for strontium with three washes. The minimum detectable activity for the method was 0.2 Bq or 40 Bq l(-1). Measurement accuracy (relative bias, B(r)) and repeatability (relative precision, S(B)) of the method for the determination of (90)Sr were found to be -1 and 4.7 %, respectively. Excellent linearity (r(2) > 0.999) was established over an activity range from 3.25 x 10(2) to 3.25 x 10(4) Bq l(-1). The method was also found to be very robust (S(B) < 5 %) against the matrix effect from different urine samples. Performance of the rapid bioassay method for sensitivity, accuracy and repeatability evaluated against the performance criteria for radiobioassay (ANSI N13.30) was found to be in compliant. Considering the simplicity, excellent analytical figures of merit, fast sample turnaround time (<1 h) and cost efficiency (<30 USD per sample) of the developed method, it is very promising as a rapid bioassay method for supporting the medical response to an emergency where internal contamination of (90)Sr is involved.

Determination of an environmental background level of 90Sr in urine for the Hanford bioassay program.

During the decommissioning and maintenance of some of the facilities at the U.S. Department of Energy Hanford Site in Washington State, workers have potential for a Sr intake. However, because of worldwide radioactive fallout, Sr is present in our environment and can be detectable in routine urine bioassay samples. It is important for the Hanford Site bioassay program to discriminate an occupational intake from a non-occupational environmental one. A detailed study of the background Sr in the urine of unexposed Hanford workers was performed. A survey of the Hanford Site bioassay database found 128 Hanford workers who were hired between 1997 and 2002 and who had a very low potential for an occupational exposure prior to the baseline strontium urinalysis. Each urinalysis sample represented excretion during an approximate 24-h period. The arithmetic mean value for the 128 pre-exposure baselines was 3.6 +/- 5.1 mBq d. The 99 percentile result was 17 mBq d, which was interpreted to mean that 1% of Hanford workers not occupationally exposed to strontium might exceed 17 mBq d.

Evaluation of flow scintillation analysis for the determination of Sr-90 in bioassay samples.

An automated procedure for the determination of (90)Sr was adapted from existing methods of flow scintillation analysis (FSA) for use on aqueous samples with low levels of activity (<1000 dpm per sample). This technique employs high-performance extraction chromatography (HPEC) and an on-line liquid scintillation counter to provide automated separation and subsequent detection of (90)Sr. The total analysis time is 30 min per sample. Dilute urine samples, spiked with (90)Sr, were also processed by this method to test the application of this technique for bioassay monitoring.

Influence of human biokinetics of strontium on internal ingestion dose of 90Sr and absorbed dose of 89Sr to organs and metastases.

The objective of the present work is to apply the plasma clearance parameters to strontium, previously determined in our laboratory, to improve the biokinetic and dosimetric models of strontium-90 ((90)Sr) used in radiological protection; and also to apply this data for the estimation of the radiation doses from strontium-89 ((89)Sr) after administration to patients for the treatment of the painful bone metastases. Plasma clearance and urinary excretion of stable strontium tracers of strontium-84 ((84)Sr) and strontium-86 ((86)Sr) were measured in GSF-National Research Center for Environment and Health (GSF) in 13 healthy German adult subjects after intravenous injection and oral administration. The biological half-life of strontium in plasma was evaluated from 49 plasma concentration data sets following intravenous injections. This value was used to determine the transfer rates from plasma to other organs and tissues. At the same time, the long-term retention of strontium in soft tissue and whole body was constrained to be consistent with measured values available. A physiological urinary path was integrated into the biokinetic model of strontium. Parameters were estimated using our own measured urinary excretion values. Retention and excretion of strontium were modeled using compartmental transfer rates published by the International Commission on Radiological Protection (ICRP), the SENES Oak Ridge Inc. (SENES), and the Urals Research Center for Radiation Medicine (TBM). The results were compared with values calculated by applying our GSF parameters (GSF). For the dose estimation of (89)Sr, a bone metastases model (GSF-M) was developed by adding a compartment, representing the metastases, into the strontium biokinetic model. The related parameters were evaluated based on measured data available in the literature. A set of biokinetic parameters was optimized to represent not only the early plasma kinetics of strontium but also the long-term retention measured in soft tissue and whole body. The ingestion dose coefficients of (90)Sr were computed and compared with different biokinetic model parameters. The ingestion dose coefficients were calculated as 2.8 x 10(-8), 2.1 x 10(-8), 2.5 x 10(-8) and 3.8 x 10(-8) Sv Bq(-1) for ICRP, SENES, TBM and GSF model parameters, respectively. Moreover, organ absorbed dose for the radiopharmaceutical of (89)Sr in bone metastases therapy was estimated based on the GSF and ICRP biokinetic model parameters. The effective doses were 3.3, 1.8 and 1.2 mSv MBq(-1) by GSF, GSF-M, and ICRP Publication 67 model parameters, respectively, compared to the value of 3.1 mSv MBq(-1) reported by ICRP Publication 80. The absorbed doses of red bone marrow and bone surface, 17 and 21 mGy MBq(-1) calculated by GSF parameters, and 7.1 and 8.8 mGy MBq(-1) by GSF-M parameters, are comparable to the clinical results of 3-19 mGy MBq(-1) for bone marrow and 16 mGy MBq(-1) for bone surface. Based on the GSF-M model, the absorbed dose of (89)Sr to metastases was estimated to be 434 mGy MBq(-1). The strontium clearance half-life of 0.25 h from the plasma obtained in the present study is obviously faster than the value of 1.1 h recommended by ICRP. There are no significant changes for ingestion dose coefficients of (90)Sr using different model parameters. A model including the metastases was particularly developed for dose estimation of (89)Sr treatment for the pain of bone metastases.

[The estimation of 90Sr and 137Cs excretion parameters from the organism of wild and laboratory small mammals in vivo, after natural contamination of them in the Chernobyl zone].

In the course of laboratory experiment, parameters of 90Sr and 137Cs excretion were estimated in individuals of bank vole Clethrionomys glareolus, captured at one of the most contaminated sites of the Chernobyl zone. The animals were kept under laboratory conditions using "clean" feed during 50 days. The similar investigation was carried out with laboratory mice Mus musculus (Big Blue line) during a longer period (184 days). The measurements of 90Sr content in the animals' body were in vivo carried out, using a specially designed beta-spectrometer with appropriate software, and 137Cs one--by the gamma-spectrometer. During the experiment, the animals had lost less 0.4% of activity due to physical decay of radionuclides. The organism was depurated mainly through biological excretion. In accordance with parameters of one-component exponential decay equation, 99.3% of 137Cs initial content in vole was excreted with half-life period of 2.18 days, and mice--4.4 days (99%). 90Sr excretion had longer half-life period: 11.7 days (56%) in voles, and 49.9 days (87%) in laboratory mice. The rest radionuclides amount of given model was considered as non-excreted from the organism during the observation period. It was determined on the example of voles that 90Sr and 137Cs loss in males was faster than in females, and among females more intensive excretion was in lactating females. 137Cs excretion from the body of bank vole is mainly with urine (74.7%), whereas 90Sr one--with feces and urine in approximately equal amounts. Due to the birth of babies and consequent feeding female lose appreciably less amount of radionuclides body burden than at daily loss with urine and feces.

Establishing schedules for repeated doses of strontium and for concurrent chemotherapy in hormone-resistant patients with prostate cancer: measurement of blood and urine strontium levels.

Strontium-89 (Sr-89) alone or with concurrent chemotherapy has a role in the treatment of patients with prostate cancer (PCP). The schedules for repeated doses of Sr-89 or for concurrent chemotherapy is undetermined. The objective of this study was to measure the effective half-life (Te) of Sr-89 using a detector available in a nuclear research facility. Blood and urine samples obtained from PCP treated with Sr-89 (Metastron, Amersham, U.K.) were measured for radioactivity with a High Pure Germanium (HPGe) detector in a gamma spectrometry system (Eurisys, France). Twenty-five urine and 22 blood samples were obtained from 8 patients during a period of 160 days after Metastron injection. Sr-89 radioactivity levels in blood and urine were quite low (<8.2 x 10(-3) microCi/mL) in all patients after 21 days, whereas Sr-85 (available in 0.5% of Metastron) urine and, to a lesser extent, blood radioactivity levels were moderately high and could be detected up to 160 days. Based on Sr-85 urine levels, the calculated Sr-89 Te ranged from 9.6 to 20.7 days. Sr-89 Te can be routinely calculated in PCP based on HPGe detection of Sr-85 radioactivity levels in urine. This measurement can establish schedules for either repeated doses of Sr-89 or concurrent chemotherapy.

Levels of 90Sr and 137Cs in the urine of Finnish people.

The aim of this study was to estimate the current concentrations of 90Sr and 137Cs in the urine of Finnish people and to estimate the doses. Two to three daily urine samples were collected from 18 adult Finnish volunteers in connection with studies of 137Cs body burdens in 1999-2001. The 90Sr activities in urine varied between 1.4 and 11 mBq l(-1). The 137Cs activity in urine varied between 0.36 and 56 Bq l(-1). The daily urinary excretion was found to be 4.8-17 mBq for 90Sr and 0.81-68 Bq for 137Cs. Assuming that the daily 90Sr intake was constant and that 18% of the ingested activity was excreted in urine, the mean intake in the investigated group would vary between 27 and 96 mBq d(-1). Based on these estimated intake values, the respective annual effective internal doses from 90Sr and 90Y varied from 0.3 to 1.0 microSv and from 137Cs from 4 to 350 microSv during the sampling period.

Cytogenetic damage in lymphocytes of healthy and thyroid tumor-affected children from the Gomel region (Belarus).

During 1994, 19 thyroid tumor-affected children and 17 healthy children from the Gomel region, one of the areas most polluted by the Chernobyl fallout, were analysed for (i) the presence of in their urine and (ii) chromosome aberrations (CA) in circulating lymphocytes. They were compared with 35 healthy children from Pisa, Italy. Tumor-affected children showed significantly (p<0.05) higher levels in their urine as compared to healthy controls from the Gomel region. No radioactivity was found in urine from the Pisa controls. CA frequency was significantly higher in tumor-affected children compared to the Gomel controls, but was not significantly different between Gomel and Pisa controls. However, dicentric chromosomes were found in a significantly (p<0.01) greater proportion in both affected and healthy Gomel children (3.4 and 1.3/1000 cells, respectively) as compared to the Pisa controls (0.4/1000 cells). Multiple regression analysis showed that the proportion of cells with acentric fragments, dicentric and ring chromosomes was significantly correlated (p<0.05) with the amount of excreted in their urine. These findings suggest that children from the Gomel region were still being exposed to radionuclides, which makes it possible to study a dose-effect relationship.

A process for the recovery of strontium from the urine of patients injected with 89Sr.

89Sr is a beta emitter used for palliation of pain in patients with metastatic bone cancer. After each intravenous administration, up to 80% of the isotope is eliminated in the urine. A simple chemical process is described, which permits the recovery and purification of the 89Sr from the urine.

Determination of strontium-90 in water and urine samples using ion chromatography.

A semi-automated method was developed for the determination of 90Sr in water and urine samples using ion chromatography. Yttrium-90 in secular equilibrium with 90Sr was initially extracted from the sample solution buffered to pH 5 using a high-capacity iminodiacetate chelating resin. At this pH, transition metals, lanthanides and actinides were extracted by the resin. The extracted metals were then transferred on to a separator column where they were separated and eluted as weak acid anionic complexes. The transition metals were eluted first by using a pyridine-2,6-dicarboxylate eluent, then the lanthanides, actinides and 90Y were eluted from the column by using an oxalate-diglycolate eluent. The fraction containing 90Y was then collected and beta-counted. For water samples, a minimum of sample preparation was required prior to chromatography, whereas an oxalate coprecipitation was included as a preconcentration step for urine samples. The derived recoveries for 90Sr for surface water, rain water and urine samples were 91.7 +/- 1.8, 91.9 +/- 1.6 and 90.0 +/- 2.7%, respectively, and the minimum detectable activity using gas flow proportional counting was 8 mBq.

85Sr contaminant as a reliable tracer of 89Sr for monitoring urinary radioactivity in patients treated with 89Sr for bone metastases.

Measurement of radioactivity levels in the urine of patients undergoing strontium-89 therapy can be used to evaluate the efficacy of therapy or for patient's management (radiation protection rules and waste disposal). The complex beta counting procedures require extensive sample manipulation during preparation of the liquid scintillation cocktail. The high activity levels that may be found permit one to measure 89Sr activity sample by counting the low yield gamma emission (909 keV) of the radionuclide. However, the contamination of 85Sr due to the reaction for producing 89Sr, if measured with sufficient precision, could be used to evaluate 89Sr activity in urine samples. In other words, the contaminant 85Sr can be used as a tracer of 89Sr. This method was tested in four patients and the accuracy was found to be sufficient to obtain the individual time-activity curves of the urinary excretion.