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Certified reference materials (CRMs) of the fish meat powder and the fish bone ash for validation of measurement of anthropogenic nuclides (134Cs, 137Cs and 90Sr) related the Fukushima Daiichi nuclear power plant accident were developed using an inter-laboratory comparison. This paper discusses the strategy of development including selection of raw material, the preparation and certification procedures applied for CRM production. In particular, some detailed data are presented for the homogeneity study and inter-laboratory experiment for the certification. The results of inter-laboratory comparison not only to certify CRMs but also showed analytical performance of the anthropogenic nuclides in Japanese laboratories.

An example of uncertainty evaluation of an efficiency curve is reported. In the applied method, the efficiency curve is determined through the weighted least square method based on measured efficiencies employing a mixed-radionuclide standard source. The variance-covariance matrix of the efficiencies is determined by evaluating the uncertainties of the counting, the calibrated radioactivities, the correction factors for true coincidence summing, and the inadequacy of the fitting function. The proposed method can be a basis to develop a more general procedure.

Certified reference materials (CRMs) for food analysis were developed in an inter-laboratory experiment for validation of measurement of radiocesium in foodstuffs. Since 2012, five series of CRMs were developed, including for brown rice grain, soybean powder, beef flake, shiitake mushroom powder and marine fish (meat and bone parts). This paper discusses the strategy of development, including choice of CRMs developed and the preparation and certification procedures applied for CRM development. In particular, some detailed data are presented for the most popular CRMs developed: brown rice grain, soybean powder and beef flake.

Neutron spectra were measured by the time of flight method using a rotating disk chopper system in the JRR-3M prompt gamma ray analysis system. Effective g-factors for non-1/v elements such as Cd, Sm and Gd were calculated from the measured neutron spectra and the neutron cross section data, and they was used for correcting the k 0-factors. The resulting k 0-factors for the cold and thermal neutron beams agreed within 10%. Furthermore, the prompt gamma ray emission probabilities of Cd, Sm and Gd were derived from the corrected k 0-factors using other relevant physical constants.

k0標準化法を用いた機器中性子放射化分析法（k0-INAA）は，比較標準を必要としないため，試料の調製から照射•測定までの操作が容易になり，更に定量限界以上であれば試料中に存在するあらゆる元素の定量が可能となる．日本原子力研究開発機構の研究炉JRR-3とJRR-4におけるk0-INAAの適用性と信頼性を評価するために，大気汚染関連の環境標準物質であるNIST SRM1633a（Coal Fly Ash），NIES CRM No.8（Vehicle Exhaust Particulates），NIST SRM2783（Air Particulate on Filter Media）を用いて，長期間の繰り返し分析を行った．ZrとAuモニターを用いて中性子スペクトルパラメータを求めることにより，照射場に依存せずに正確な定量値が得られることを確認した．NIST SRM 1633aでは，22元素が認証値（参照値）からの定量（平均）値の偏差が5% 以内，11元素が3% 以内であり，本法が正確さの優れた分析法であることを示した．更に，本法を2004年8月から2005年3月に捕集した茨城県内の大気エアロゾル試料に適用し，粒径別（PM0.4，PM0.4-2.1，PM2.1-11）の微量元素濃度の変動を明らかにした．

By probing Doppler broadened line-shapes of prompt γ -ray at 478 keV emitted from moving 7*Li produced via the 10B(n, γ)7*Li reaction, matrix materials containing and/or surrounding boron species were non-destructively characterized for several growing stages of soybean. It was elucidated that boron is in the form close to each other for both the dry seeds for planting and the dry seeds harvested, while it was revealed that boron exists in an aqueous solution for the two stages of growing, swelling seeds with a bourgeon and a greenish sprout. This work is the first biological application of Doppler broadening of neutron induced prompt γ -rays.

In order to determine multiple elements by k0 standardization-based neutron induced prompt gamma-ray analysis (PGA), measurements and evaluation of k0 factors for the elements have been performed. The k0 factors using Cl as a comparator for 27 elements, which are effective for the analysis by PGA, were measured with precision almost less than 3% using the cold and thermal guided neutron beams at JRR-3M. The accuracy of the k0 factors were better than 10% except for the non-1/v elements of Cd and Sm. Neutron spectrum correction is necessary for common use of k0 factors of the non-1/v elements.

飛灰, 焼却灰, 廃ガラス, 廃陶磁器類を試料として, 溶出液のpHとホウ素溶出濃度との関係を調べた。溶出液のpHが低いほどホウ素の溶出濃度は高く, また一度溶出したホウ素は, 溶出液のpHを上昇させると再吸着か水酸化物への吸着・共沈によって液相から失われることが判明した。ホウ素の溶出・吸着にはpHが大きな影響をもつことが再確認されたが, そのメカニズムは不明である。逐次抽出法とICP発光法・即発ガンマ線分析を組み合わせて各種廃棄物に含まれるホウ素の分画 (「イオン交換態」, 「炭酸塩結合態」, 「Fe-Mn酸化物結合態」, 「有機物結合態」, 「ケイ酸塩結合態」) を行った結果, 飛灰などはもっとも溶出しやすい「イオン交換態」に, ガラス・溶融鉱滓は最も溶出しにくい「ケイ酸塩」分画に, それぞれ多くのホウ素を含む傾向があった。しかし同じカテゴリーの廃棄物でも試料によって5分画の相対存在度が異なり, カテゴリーごとに一般化することはできなかった。告示46号試験法による溶出量は「イオン交換態」分画に存在するホウ素量をよく説明できたが, 潜在的に溶出可能なホウ素量を予測するには不十分であった。鉱滓以外の廃棄物は, 高温 (1300℃) 処理によって試料中ホウ素が「ケイ酸塩」分画に移行し, 溶出しにくくなり, 試料を溶融後に埋め立てることでホウ素溶出を低減できることが示唆された。

Mantle wedge below the Northeast Japan arc contains hydrous fluids that dehydrated from two parts of the descending slab: a sediment layer and an altered oceanic crust (AOC). In order to estimate the weight percent of a sediment-derived fluid in the mantle wedge, we determine boron and other element contents of Japan Trench sediments and Iwate basaltic lavas on the Northeast Japan volcanic front. Trace element contents of the trench sediments are used to estimate those of the sediment-derived fluid, and previously reported trace element contents of the AOC are used to estimate those of the AOC-derived fluid. Examination of mobile/immobile element ratios (B/Sm, Ba/Sm, K2O/Sm, B/Zr, Ba/Zr, K2O/Zr) of the two slab-derived fluids and Iwate basaltic lavas, indicates a mixing ratio between the AOC-derived fluid and the sediment-derived fluid is 90:10 in the mantle wedge beneath the Northeastern Japan arc. The mobile/immobile element ratios also suggest that the subducted sediment recycle to the mantle wedge beneath Northeast Japan as sediment-fluid rather than sediment-melt. Since the weight fraction of the total slab-derived fluid in the mantle wedge is estimated to be less than 1 wt%, an addition of a small amount (

Multi-element and isotopic analyses of oils and marine environmental samples were carried out to estimate a contamination source using a "finger printing" method. Elemental analyses were carried out using neutron-induced prompt gamma-ray analysis (PGA), instrumental neutron activation analysis (INAA) at the Japan Atomic Energy Research Institute, Tokai-mura, Japan (JAERI) and ICP-MS in the IAEA Marine Environment Laboratory, Monaco (MEL). Fifteen elements including light elements, H, B, N, Si and Ca, which cannot be determined by INAA and ICP-MS, were determined by PGA. A total of 47 elements were determined in the present study. The potential of PGA for the determination of isotopic ratios was tested by measuring 34S/32S ratios in oils. The evaluation of historical records of marine environmental conditions using annual bands in coral samples was also investigated.

廃棄物埋立処分場浸出水中に高頻度, 高濃度に見出されるホウ素の起源をさぐるために, 159試料の各種廃棄物のホウ素含有量および環境庁告示46号試験法に準じた試験法による溶出濃度を測定した。焼却残さ (ばいじん・飛灰, 燃えがら・焼却灰) , 鉱滓のホウ素含有量が汚泥, 建築廃材, 廃プラスチックなどにくらべて高いこと, 公定法による溶出試験では, どの廃棄物も高い溶出濃度を示さなかったこと, などが明らかとなった。しかし, 焼却残さの溶出濃度は, 溶出に用いた水のpHに依存し, 埋立地浸出水に通常見られる中性においては, 溶出試験公定法で得られる溶出濃度の4倍程度多く溶出する可能性が統計的に推計された。一方, ガラス・陶磁器類, 強化プラスチックなどは高いホウ素含有量・溶出濃度を示す場合があった。以上の結果から, 廃棄物埋立処分場浸出水の起源となる可能性の高い廃棄物として, 焼却残さ, 鉱津, ガラス・陶磁器類, 強化プラスチックを挙げることができた。

Multielement determination in reference materials of diet and its relatedsamples has been studied by a k 0 based neutron-induced prompt gamma-ray analysis(PGA) by using cold and thermal guided neutron beams of JRR-3M at JAERI. Hydrogen,B, C, N, Na, S, Cl, K and Ca were determined in the reference materials ofNIES and NIST typical diet and milk powder samples. Analytical results ofthe NIST Standard Reference Materials agreed with the certified values towithin 7%.

Metallic impurities in high-purity type IIa and conventional type Ib diamond single crystals grown by high-pressure and high-temperature (HPHT) synthesis were determined by neutron activation analysis using thermal neutrons. Metallic impurities of Fe, Co, Cr and other minor elements were detected in the high-purity type IIa diamond crystal. The typical quantities of these metallic impurities were a few ppb. The influence of these metallic impurities on the electrical properties of the type IIa diamond crystal was practically negligible compared with nitrogen and boron impurities behaving as a donor and an acceptor, respectively. In addition to the impurities detected in the type IIa diamond crystal, Ni impurities of several hundreds of ppb were detected in conventional type Ib diamond crystals. A difference in molten metal solvents used in the synthesis of each diamond crystal resulted in the difference in metallic impurities.

An efficiency curve was constructed for a large-volume Ge detector located at the thermal-neutron beam line of the JRR-3M reactor at the Japan Atomic Energy Research Institute (JAERI). The calibrations for γ-ray energies below 2754 keV were accomplished with a large number of radioactive sources and above 2754 keV with the 12C(n,γ) and 14N(n,γ) reactions. This detector and its efficiency curve were subsequently used to determine accurately the photon emission probabilities of γ rays from the decays of 56 Co (T 1/2 =77 d ) and 66 Ga (9.5 h ) and from the 35Cl(n,γ) reaction. These radiation sources can serve as secondary standards for efficiency calibrations.

An internal monostandard method for PGAA is proposed for completely non-destructive analysis of elements in bulky samples by the use of a neutron beam guided out from the reactor. The method is essentially the same as the k0 method except that it corrects for the change of relative γ-ray counting efficiencies caused by the absorption and scattering of neutrons and absorption of γ-rays within the sample. Some examples of applications to archaeological samples of earthen wares, bronze mirrors, and to voluminous meteorite samples are demonstrated, and its future application to the in-situ studies of distribution and metabolism of a certain elements in animals is also explained.

A neutron-induced prompt γ-ray analysis (PGA) has become widely utilized due to the improved analytical sensitivities and detection limits especially by using low energy guided neutron beams. Current studies on the low energy neutron guided beam PGA are reviewed. Historical backgrounds, current analysis systems, advantages when compared with conventional NAA, standardization for elemental determination and analytical applications in JAERI of the guided beam PGA are described.

The k0 standardization method has been studied and applied at JAERI for the accurate determination of multielements by neutron-induced prompt gamma-ray analysis (PGA). The k0 factors for 26 elements using Cl as a comparator were measured by the cold and thermal neutron guided beams of JRR-3M with an uncertainty less than 3% except for a few elements. The k0 factors for most elements obtained with both cold and thermal neutrons agreed within 3%, and agreed also with those measured at other cold and thermal neutron guided beams within 10%, except for a few elements. Multielement determinations in reference materials were performed using the k0 factors obtained to evaluate the accuracy and precision of this work.

A highly sensitive neutron-induced prompt gamma-ray analysis (PGA) system, usable at both cold and thermal neutron beam guides of JRR-3M, has been constructed. The system was designed to achieve the lowest gamma-ray background by using lithium fluoride tiles as neutron shielding, by placing the samples in a He atmosphere and by using a Ge-bismuth germanate detector system for Compton suppression. The gamma-ray spectrometer can acquire three modes of spectra simultaneously: single, Compton suppression, and pair modes. Because of the low-energy guided neutron beams and the low-background system, analytical sensitivities and detection limits better than those in usual PGA systems have been achieved. Boron and multielemental determination by a comparative standardization have been investigated, and accuracy, precision, and detection limits for the elements in various materials were evaluated. The system has been applied to the determination of B and multielements in samples of various fields such as medical, environmental, and geological sciences.

Neutron induced prompt gamma-ray analysis (PGA) and instrumental neutron activation analysis (INAA) have been applied to the sediments collected from the Yasaka River estuary in Oita Prefecture, Japan. The vertical distribution of 33 elements in the sediments has been determined and compared with that in more polluted estuarine sediments. While the S content increased with increasing depth because of a sulphide accumulation under reducing condition, the increase in sulphide-forming elements such as Ag, Cd, Co and Zn was not observed in the deeper section of the Yasaka River estuarine sediments.

Determination of ppm levels of B in 21 igneous and sedimentary rocks of the Japanese geochemical reference samples prepared by the Geological Survey of Japan (GSJ) has been performed by neutron-induced prompt γ-ray analysis (PGA) using cold and thermal guided neutron beams of the JRR-3M. Owing to the Doppler broadened γ-ray line of B 478 keV, many elements such as Na, Ni, Cl and so on showed spectral interference in the determination of B. The interference was corrected by computer fitting and a reference peak method. The analytical results obtained by the present method almost agreed with the GSJ values recommended in 1994 within the standard deviation of the recommended values. Sodium contents determined by the PGA in the reference rock samples are also reported.

Neutron-induced prompt gamma-ray analysis (PGA) was applied to seven meteorite samples (Allende, Zagami, Acfer 209, ALH77005, ALH84001, EET79001 and Neagari). Samples were irradiated in both the thermal neutron and the cold neutron guided beams of JRR-3M at JAERI. Multiple samples of an Allende standard powder were analyzed for Si using two different methods: (1) the comparison method, using a Si standard, and (2) the mono-standard method, using Fe as an internal reference element. The Si concentrations determined by these two methods are in good agreement with literature values. The analytical sensitivity for Si using the cold neutron guided beam is∼14.3× higher than that for the thermal neutron guided beam. Other elements determined (B, Ca, Ti and S) also showed higher sensitivities using the cold neutron beam. The other meteorites studied showed some anomalous B and S values likely due to the effects of terrestrial weathering/contamination.

An accurate and efficient analytical method using neutron-induced prompt γ-ray was developed for the determination of boron contents in volcanic rocks. We corrected the effect of sample geometry and flux fluctuation by using silicon as an internal standard. However, we found that the slopes of the calibration line vary among volcanic samples with different matrix. Because the increase of boron activity correlates positively with γ-ray count rate of hydrogen (water), we call this as the hydrogen effect. The hydrogen effect was confirmed by our experiment in which the boron activities showed systematic increase with the amount of added hydrogen (water). Most volcanic rocks, however, contain little water (

Prompt γ-ray analysis using the internal monostandard method was applied to voluminous archaeological bronze mirrors produced in ancient China. Sn/Cu content ratios were determined nondestructively by this method. Furthermore, Au/Cu, As/Cu, and Sb/Cu content ratios were determined by means of measuring decay γ-rays emitted from radioactive nuclides produced within samples via (n,γ) reactions. It is clear that the Sn/Cu content ratios in bronze mirrors produced in the Sung era is smaller than in ones produced in between the Han and the Tung era.

Iron and boron species in the products of thermit reaction of aluminum, iron oxide, and boron oxide were characterized by Mossbauer spectroscopy, X-ray diffraction, and prompt γ-ray analysis. It was revealed that iron and boron products of the thermit reaction are composed of intermetallic compounds with aluminum.

In prompt γ-ray measurements following slow-neutron capture, the Doppler-broadened 478 keV peak resulting from capture in boron was deliberately overlapped with prompt γ-rays of similar energies resulting from capture in sodium, cobalt, and nickel. A peak decomposition method was developed in which the broadened line shape was represented by an integral of the Gaussian function and the spectrum in the 455–490 keV region was decomposed into a broad peak and interfering normal peaks by using a nonlinear least-squares procedure. The accuracy and detection limits of the current method for boron determination were confirmed by comparing the analytical results with those obtained by the reference line method and with boron amounts known during sample preparation by direct weighing and aliquoting.

The chemical composition of the high-level radioactive waste glass which was produced in the Windscale Vitrification Plant at Sellafield was determined by ICP-AES. The chemical analysis was performed in shielded cells and glove boxes at the Japan Atomic Energy Research Institute. The sample was dissolved by alkaline fusion with sodium peroxide and acidic decomposition with hydrofluoric and perchloric acids for determining Si and B, and Li, Na, Mg, Al, P, Cr, Fe, Ni, Sr, Zr, Mo, La, Ce, Nd and U, respectively. High accuracy of the analytical results was confirmed by analyzing the reference material of glass (NIST SRM1412) and a simulated inactive waste glass. The analytical results of the high-level radioactive waste glass were in good or fair agreement with the values estimated by British Nuclear Fuels plc, which were calculated from the analytical data of the high-level radioactive liquid waste and glass frit used in the production of the radioactive waste glass.

短寿命核種20F(半減期11.00 s)を利用した機器中性子放射化分析法(INAA)による,粉末窒化ケイ素中痕跡Fの非破壊迅速定量法の検討を行った.分析は,JRR-3M放射化分析設備で5秒照射し,7秒後に10秒放射能測定を行う単一照射法と,単一照射法を10分以上の間隔で5回繰り返す,繰り返し照射法により行った.単一照射法では窒化ケイ素中2μg/g以上のFの定量が可能であり,更に,繰り返し照射法では,単一照射法より検出限界が1/3～1/5以下に,又,定量精度も約4倍改善された.照射中のFの蒸発及びNaの妨害核反応の影響についても調べた結果,これらは無視できるほど小さいことが分かった.本法による標準物質Oparl Glass (NIST SRM91)及びOyster Tissue (NIST SRM1566a)中のFの定量値は,その相対標準偏差(5.1～5.9%)の範囲以内でNISTの認証値及び参考値とほぼ一致した.更に,茶葉標準物質(NIES No.7)中のFの定量も行った.又,本法の分析誤差に最も影響するAl含量とFの検出限界との関係も明らかにした.

日本原子力研究所の研究用原子炉JRR-3Mの放射化分析設備(PN-3)を使用し,半減期秒オーダーの短寿命核種を利用する中性子放射化分析(NAA)の基礎検討を行った.PN-3は,高速の気送管照射装置と高計数率用γ線スペクトロメーターから構成され,短寿命核種を利用したNAAを迅速に行うことができる.短寿命核種NAAで重要な高計数率γ線測定法,照射カプセル材質,中性子束の変動等基礎条件の検討を行い,(n,γ)反応によって半減期0.7～100秒の放射性核種を生成する20元素について,分析感度と検出限界を測定した.本法ではSc,In,Dy,Hfが最も高感度であり,その検出限界は4.2～14ngであった.又,他の方法では定量が困難なFの検出限界は530ngであった.本法が有効な元素F,Se,Sc,Hf,In及びDyについて,各種標準物質等の分析に応用し,精度,正確さ及び検出限界を評価した.

即発γ線分析装置を用いて火山岩試料中のホウ素を短い装置使用時間で正確に定量する方法を検討した。ドップラー効果により台形型になったホウ素ピークの妨害となるナトリウムピークの除去方法を検討し, この影響はホウ素ピークの右半分を使えば避けることができることを明らかにした。火山岩中のホウ素の定量の際には試料の大きさの違いによりホウ素のγ線強度 (cps/g) は変化することを示し, この変動をケイ素を用いた内部標準法で補正できることを提案した。以上の分析方法を用いて地質調査所の火山岩標準試料中のホウ素含有量の定量を数回行ったところ, 再現性はよく, 各測定結果は9%以内で一致した。また今回求めたホウ素含有量は推奨値と一致した。

Neutron induced prompt γ-ray analysis (PGA) and instrumental neutron activation analysis (INAA) have been applied to the sediments collected from the Tama River estuary in Tokyo, Japan. The vertical distribution of 24 elements in the sediments was determined and the factors goveming the vertical profiles have been discussed. Major elements are distributed depending on weathering that proceeds much with increasing depth. Cadmium is highly concentrated in the deeper layer where sulphate ion is reduced to hydrogen sulphide. The distribution of several rare earth elements is also presented

This paper describes effect of base profile for precise measurement of photon energy in prompt γ-ray analysis (PGA). The base profile has been examined in the vicinity of full energy (FE), single escape and double escape peaks. Major origins of step-wise base profiles are single and double escape events for triple photon annihilation and single and double Compton escape events for double photon annihilation in the detector, in addition to general events for the FE peak. A formula has been proposed for the quantitative characterization of the base profile.

The application of stable isotope analysis using neutron-induced prompt γ-ray analysis (PGA) with cold/thermal neutron beams for the tracer study of geological materials are discussed. Silicon has three natural isotopes differing in abundance:28Si (92.23%),29Si (4.67%) and30Si (3.10%). For the purpose of the assessment of Si migration in engineered barrier material, enriched30Si can be used as a tracer due to its nuclear and chemical properties. Isotope analysis of30Si was performed by PGA during the tracer study. Neutron intensity at the sample position was 1.4·108 n¢cm−2·s−1, 2.4·107 n·cm−2·s−1 for cold and themal neutron guided beams of JRR-3M, respectively. Calibration curves and analytical sensitivity of30Si were determined based on measurement of standard samples. BG and detection limits for30Si analysis were also measured in Japanese bentonite (Kunigel V1 and Kunipia F) and their pore water. Fiffteen elements were determined simultaneously using PGA.

Non-destructive multi-element determination in environmental samples by neutron-induced prompt γ-ray analysis (PGA) has been investigated. Comparative standardization for the elements including H, B, C, N, Na, Mg, Al, Si, P, S, Cl, K, Ca, Ti, Mn, Fe, Co, Cd, Sm, Gd, Hg by PGA has been carried out using the cold and thermal guided neutron beams of JRR-3M reactor and then several environmental reference materials have been analyzed. Accuracy and precision of better than 20% were found for these elemental analyses except for H, C, N and Cl in biological samples. Detection limits in various environmental matrices were 25 to 820 ng/g for B, Cd, Sm and Gd, 1.1 to 820 μg/g for H, Na, S, Cl, K, Ti, Mn, Co and Hg, and 0.031 to 10% for C, N, Mg, Al, Si, P, Ca and Fe. The present method is being applied to environmental studies of post war Persian Gulf together with INAA and ICP-MS.

A non-destructive multi-element determination using a cold neutron-induced prompt γ-ray analysis (PGA) has been investigated. The elements H, C, N, Na, Mg, Al, Si, P, S, Cl, K, Ca, Ti, Mn, Fe, Co, Cd, Sm, Gd and Hg were determined by a comparative standardization using the cold neutron guided beams of JRR-3M (upgraded Japan Research Reactor No. 3). To accurately determine the amounts of elements, possible interferences by other elements and background counts were examined and evaluated. Many elements in several reference materials, such as geological, environmental, and biological samples, coal and fuel oil, were determined, and the accuracy and precision of a multi-element determination were estimated. Toxic elements as, such Cd and Hg, at μg/g levels were accurately determined in environmental samples. The detection ma limits in various trices were from 25 to 820ng/g for Cd, Sm and Gd, 1.1 to 820μg/g for H, Na, S, Cl, K, Ti, Mn, Co and Hg, and 0.031 to 10% for C, N, Mg, Al, Si, P, Ca and Fe.

The spectral lines of the 478 keV prompt γ-ray from7*Li produced in the10B(n, α)7*Li reaction were measured for a silicon wafer coated with a thin boron layer using neutron beams. The shapes of the Doppler broadened lines were found to depend greatly on the angle between the measurement axis and the boron layer surface. The angular dependence was interpreted according to whether the energetic7*Li ions are ejected into air or into the substance in the forward or backward recoil of7*Li to the γ-ray detector.

Appearance of the random summing shape on a shoulder of a photopeak shape was examined by co-acquisition of an EC decay source ( 54 Mn) or a β − -IT transition source ( 137 Cs 137m Ba) and precision pulser signals. An empirical functional modelling for the random summing shape can be made in the region close to the photopeak. The co-acquisition technique with the pulser revealed a direct measure of the random summing counting loss of the photopeak counts.

In anodization of alminum, electrolyte anions are incorporated into the oxide film from the liquid electrolyte. The anion distribution is related to physical and chemical properties and the mode of film formation. Prompt Gamma-ray Analysis (PGA) has higt sensitivity (2000cps·mg-1) and a low detection limit (0.002μg) for boron, so it is applicable to the determination of boron in aluminum oxide films.It was found that the average boron content was 0.25wt% with electrolysis at 25°C in a 0.5mol·dm-3 H3BO3-0.05mol·dm-3 Na2B4O7 solution. Differences of the electrolytes and in formation voltages, i.e. in the thickness of the barrier films, had little effect on this value, but it varied in proportion to the boron concentration in the electrolyte and decreased at higher temperatures.Boron was distributed to a distance of half the depth from the surface, and was not detected near the oxide/metal interface. This result can be explained on the basis of the transport number (0.45-0.6) of Al(III) ion and by the absorption of borate ions into hydrous aluminum oxides.

放射化学中性子放射化分析法(RNAA)により,二酸化ケイ素及びAl標準物質中の極微量UとThの定量を行った.試料とU-Th標準試料を原子炉(JRR-4又はJRR-3M)で照射後,テノイルトリフルオロアセトン(TTA)液-液抽出法により239Npと233Paを分離し,そのγ線スペクトル測定によりUとThを定量した.Uは照射した試料に237Npをトレーサーとして添加し,その化学収率補正を行う方法によっても定量した.本法による定量値と各標準物質の認証値とを比較した結果,二酸化ケイ素標準物質ではU,Thとも±20%以内で一致した.Al標準物質では,本法の定量値は認証値よりUの場合6.4～13%低く, Thの場合は16～17%高い値となった.本法の検出限界は,二酸化ケイ素標準物質でU 12, Th 76 pg/g及びAl標準物質でU 11, Th 45 pg/gであった.

Multi-element determination in reference materials of soils (JSAC 0401, JSAC 0411) and sediments (NMIJ CRM 7302-a, NMIJ CRM 7303-a), which were prepared at the Japan Society for Analytical Chemistry and the National Institute of Advanced Industrial Science and Technology of the National Metrology Institute of Japan, respectively, has been carried out by neutron-induced prompt gamma-ray analysis (PGA) using standard addition and k0-standardization methods. Firstly, the absolute Ti concentrations in the samples were determined accurately by the standard addition method. Secondly, the relative multi-element concentrations were determined by the k0-standardization method. Finally, the absolute multi-element concentrations were obtained by normalizing the relative multi-element concentrations with the absolute Ti concentration in the samples. The 15 elements, such as H, B, Na, Si, S, Cl, K, Ca, Ti Cr, Mn, Fe, Cd, Sm and Gd were determined by k0-PGA. The analytical results of these reference materials agreed with the certified or reference values within about 10%.

Nondestructive determination of trace amounts of boron in various materials was carried out using neutron induced prompt y-ray analysis. A 100-250 mg sample was irradiated with cold or thermal guided neutrons of JRR-3M, and the Doppler-broadened 478 keV prompt γ-rays were measured. To determine the B content accurately, analytical conditions such as the sample size, the hydrogen content of the sample, and any interferences due to other elements were examined. Nanogram to microgram per gram levels of B were determined in reference materials, including rocks, botanical samples, coal and coal fly ash, various types of sediments, animal tissue, environmental samples, and reactor materials, with accuracy and precision of better than 20%. The detection limits varied depending on the type of sample : 12-22 ng/g for graphite and Be ; 120-260 ng/g for marine environmental materials, coal fly ash, and pepperbush ; and 57-98 ng/g for the other materials.

Instrumental charged particle activation analysis (CPAA) for determining boron in a thin surface layer of silicon was developed. The nuclear reaction and incident energy were selected in order to minimize any interference from surface or bulk impurities. Thin boron film was used as a standard sample and its boron content was determined by neutron induced prompt γ-ray analysis. As a result, we were able to determine11B and10B at 1015 atoms/cm2 with an accuracy of better than 3% by 4 MeV proton and 7 MeV α-bombardment, respectively. Each boron isotope could be determined down to 1013 atoms/cm2. Our CPAA was applied to determine boron in a boron implanted silicon wafer of a SIMS standard sample.