Radioactive strontium-90 scattered by a nuclear power plant accident was specifically quantified by conventional inductively coupled plasma quadrupole mass-spectrometry (ICP-QMS) preceded by online chelate column separation (based on lab-on-valve) and oxygen reaction (designated the cascade step). The proposed system overcomes the isobaric interference of 90 Zr, whose soil concentration exceeds that of 90 Sr by more than six orders of magnitude. In addition, the system requires no ultimate mass spectrometry or radioactive 90 Sr standards. The radioactive 90 Sr standard was replaced with the stable isotope 88 Sr as a pseudo-standard. The modified ICP-QMS system yielded a precise, reproducible sharp 90 Sr peak in the ICP-MS profile. The elution time of 90 Sr was highly reproducible (RSD ¼ 0.5%).After implementing the cascade-step, the detection limit (DL) was 2.3 Bq L À1 (equivalent to 0.46 ppq as 90 Sr). Analysis of microwave-digested soil yielded a DL of 3.9 Bq kg À1 (equivalent to 0.77 ppq as 90 Sr).The 90 Sr from environmental contaminated soil samples collected from areas at a distance of 10 and 20 km from the Fukushima Daiichi nuclear power plant ranged from 52 Bq kg À1 to 73 Bq kg À1 , with no statistical difference between the proposed and general methods at 95% confidence level. The proposed method offers an attractive alternative use for ICP-other ionization mass spectrometry as an enrichment or purification step, thereby expanding the scope of ICP-mass-spectrometric analysis.

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Online solid-phase extraction (SPE) coupled with inductively coupled plasma mass spectrometry (ICPMS) is a useful tool in automatic sequential analysis. However, it cannot simultaneously quantify the analytical targets and their recovery percentages (R%) in one-shot samples. We propose a system that simultaneously acquires both data in a single sample injection. The main flowline of the online solid-phase extraction is divided into main and split flows. The split flow line (i.e., bypass line), which circumvents the SPE column, was placed on the main flow line. Under program-controlled switching of the automatic valve, the ICPMS sequentially measures the targets in a sample before and after column preconcentration and determines the target concentrations and the R% on the SPE column. This paper describes the system development and two demonstrations to exhibit the analytical significance, i.e., the ultratrace amounts of radioactive strontium ( 90 Sr) using commercial Sr-trap resin and multielement adsorbability on the SPE column. This system is applicable to other flow analyses and detectors in online solid phase extraction.

Thermal ionization mass spectrometry (TIMS) was used to directly quantify an ultratrace of radioactive 90 Sr in microliter droplet samples. No chemical separation was required in removing isobaric interferences on M = 90 such as 90 Zr and organic molecules in the mass spectrum because the difference in evaporation and ionization (emission) temperature among organic molecules, Zr and Sr, allows us to control the emission manner and significantly suppress the isobaric interferences. Direct quantification was achieved by improving the intercalibration of Faraday cups and ion counting in an isotope dilution (ID) method. Furthermore, the use of a total evaporation method (TE) enhanced the detection efficiency by the complete collection of the 90 Sr ion beam from the samples and minimized the complexity of the fractionation effect in the isotope ratio calculation. In this study, 1 fg of 90 Sr (equal to activity of 5 millibecquerel (mBq)) in a very low-volume sample with 10 8 times greater isobaric interference from 90 Zr was successfully measured using the proposed ID-TE-TIMS method. The limit of detection was 0.029 fg (equal to 0.15 mBq) without any preconcentration. To demonstrate the wide usability of this method, low-volume samples of tears, eyelashes, saliva, environmental standards, and water samples (i.e., seawater and ground water) were analyzed within 1 h. The relationship of the measured values between this ID-TE-TIMS method and a radiometric analysis was shown to have good linearity.

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A contamination with the ubiquitous radioactive fission product 137Cs cannot be assigned per se to its source. We used environmental samples with varying contamination levels from various parts of the world to establish their characteristic 135Cs/137Cs isotope ratios and thereby allow their distinction. The samples included biological materials from Chernobyl and Fukushima, historic ashed human lung tissue from the 1960s from Austria, and trinitite from the Trinity Test Site, USA. After chemical separation and gas reaction shifts inside a triple quadrupole ICP mass spectrometer, characteristic 135Cs/137Cs isotope signatures (all as per March 11, 2011) were obtained for Fukushima- (∼0.35) and Chernobyl-derived (∼0.50) contaminations, in agreement with the literature for these contamination sources. Both signatures clearly distinguish from the characteristic high ratio (1.9 ± 0.2) for nuclear-weapon-produced radiocesium found in human lung tissue. Trinitite samples exhibited an unexpected, anomalous pattern by displaying a low (<0.4) and nonuniform 135Cs/137Cs ratio. This exemplifies a 137Cs-rich fractionation of the plume in a nuclear explosion, where 137Cs is a predominant species in the fireball. The onset of 135Cs was delayed because of the longer half-life of its parent nuclide 135Xe, causing a spatial separation of gaseous 135Xe from condensed 137Cs, which is the reason for the atypical 135Cs/137Cs fractionation in the fallout at the test site.

This paper describes a rapid quantification method for radioactive strontium ( 90 Sr) in fresh foods (perishable foods) and has been comparatively evaluated with the common classical radiometric quantification method. Inductively coupled plasma–dynamic reaction cell-mass spectrometry with online solid-phase extraction (cascade-ICP–MS) rapidly determines 90 Sr in a pure water-based sample. Despite its advantages, its application to fresh foods (perishable foods) has not yet been reported; however, the analytical potential of this method for fresh foods must be evaluated. In this study, 90 Sr was determined in 12 fresh foods via improved cascade-ICP–MS (Icas-ICP–MS). Addition and recovery tests were demonstrated using real samples of grape, apple, peach, Japanese pear, rice, buckwheat, soybean, spinach, shiitake mushroom, grass, sea squirt, and flounder. With a decomposed solution of Japanese pear, the measurement value coincided with the amount of spiked 90 Sr. The reproducibility of the measurements was represented by relative standard deviations of 14.2 and 5.0% for spiked amounts of 20 and 200 Bq/kg, respectively ( n = 10), and the recovery rates were 93.7 ± 7.1%. In this case, the limit of detection (LOD) was 2.2 Bq/kg (=0.43 pg/kg). These results were compared with the data obtained using a common classical radiometric quantification method (nitrate precipitation-low background gas flow counter (LBC) method) in the same samples. Both the methods showed equivalent performances with regard to reproducibility, precision, and LODs but different analysis times. Icas-ICP–MS required ∼22 min for analysis, whereas the nitrate precipitation-LBC method required 20 days, confirming that Icas-ICP–MS is the suitable method for analyzing 90 Sr in fresh foods.

A trans-Resveratrol (Res; 3,5,4′-trihydroxystilbene, Fig. 1) is the one of the natural polyphenols, 1,2 and is included in many plants. Especially, it is known to be included in grapes and related products. 3 Recently, it was found that Res has an anticarcinogenic effect 4 and a condensation suppressive effect. 5,6 Furthermore, several medical actions, such as an antioxidization effect 7 and an anti-inflammation effect, 4 were found in succession. Thus, Res has been expected to show medical and physiological effects, and is a remarkable chemical for pharmacology and medical science. 8 So far, solvent extraction 9-11 and solid-phase extraction 12,13 have been known to be pretreatment methods in the case of Res extraction and/or separation.However, these methods have several serious problems. Concretely, in solid-phase extraction, (i) a long time is needed for elution because of the hydrophobic property for Res, (ii) a large quantity of eluent is needed, and (iii) the column becomes clogged with the sample solution when extracting from grape skins, etc. Regarding solvent extraction, (i) a large quantity of organic solvent, such as hexane, is necessary, and (ii) an evaporator is also necessary for concentration.As simple and inexpensive method, developing yeast that collects the polyphenol derivatives, was reported.14 However, regarding desorption, the yeast could not release these polyphenols. Also, since many kinds of polyphenol adsorbed on the yeast, the selectivity of Res was poor.On the other hand, cellulose, which is a biological and functional material, is made of glucose with β-1,4-glucoside bonds, and has more than ten thousand of these Dglucopyranose sections without branching. It also occurs as natural fibers, such as cotton, hemp and linen. Because the cellulose molecule has many hydroxyl groups, the chemical and physical properties involve not only the strength and elasticity of the fiber, but also the affinity and permeability by water.The authors considered the interaction between Res and cellulose, and that it would show adsorption and desorption properties. In this study, the properties of the adsorption and desorption between cellulose cotton and Res were investigated. Experimental ReagentsRes was obtained from A. G. Scientific (USA). Absorbent cotton was obtained from Hakujuji Medical Products (Japan). The organic solvents and salts were from Kanto Chemical, Co. (Japan). Malvidin-3-glucoside was from Kiriya Chemical, Co. (Japan). All other chemicals were of analytical reagent grade from Kanto Chemical, unless otherwise noted.Polyphenol standard solutions: These were prepared at 5 × 10 -3 mol L -1 by dissolving polyphenols in methanol. These solutions were stored in dark bottles at 5˚C. The working solution was prepared by dissolving the stock solution in distilled water. ApparatusA Nippon Bunko V-570 double-beam spectrophotometer and a quartz cell (light path length: 1 cm) were used for the spectrophotometry. A Tokyo Rika Kikai EYEL was used as an auto shaker. A Horiba F-22 pH meter was used for ...