高エネルギーX線を励起源とする3次元偏光光学系蛍光X線分析装置を用いて，犯罪に利用されることが多い布粘着テープの異同識別法の開発を試みた．検討の結果，識別に最適な分析条件は以下のとおりである．2次ターゲットとしてRhとAl₂O₃を用い，測定時間はそれぞれ300秒と600秒，分析に用いた元素はCa，Ti，Cr，Mn，Fe，Ni，Zn，Sr，Zr，Nb，Mo，Sb，Ba，Pbの14元素である．方法の有効性を検証するため，市販の布粘着テープ17社31試料へ応用した．糸密度と蛍光X線（XRF）スペクトルの14元素のピーク強度の組み合わせにより，31試料中29試料をうまく識別できることが分かった．識別できなかった2試料は同一起源のものと思われた．このように蛍光X線分析を用いる本方法は，非破壊で迅速，簡便であることから法科学的分析法として実用性が高いことが分かった．

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A simple pretreatment method for the determination of 24S-hydroxycholesterol in human cerebrospinal fluid by gas chromatography/mass spectrometry (GC/MS) has been developed. Esterified cholesterol was saponified by a high concentration of potassium hydroxide (25 M, 1 mL) in a small volume (10 mL) of a conical test tube with a stopper made of glass. Next, free cholesterol was extracted with a small volume of n-hexane. The combined extracts obtained by the twice extraction were then applied on a silica cartridge for solid-phase extraction. A slight amount of 24S-hydroxycholestertol was separated from a large amount of cholesterol using n-hexane and ethylacetate as an elution solvent. 24S-hydroxycholestertol and 27-hydroxycholesterol-26,26,26,27,27-D₅ as an internal standard were converted to trimethylsilyl ethers by the trimethylsilyl (TMS) reagent, and then the TMS derivatives were determined by GC/MS. The method was successfully applied to the determination of 24S-hydroxycholestertol in human cerebrospinal fluid from patients of non-neurodegenerative disorders. The pretreatment method reported here was simple and useful for one multi-specimen material pretreatment.

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近年SI単位に基づいたトレーサブルな標準ガスによる機器の校正が必要となりつつあるが，標準ガス濃度の不確かさを小さくするには高感度分析法が必要である．また，半導体技術の向上に伴い，原料ガスやパージガス中の水などの不純物の測定が重要となっている．本稿では，最初に高感度分析法により標準ガスの精度が向上する理由について述べ，次に標準ガスの調製に用いられる高純度ガス中の不純物を高感度に測定する手法・研究について詳説した．それらの分析法について実際の検出下限の比較を行うとともに，幾つかの手法についてはその原理や検出下限についての定量的な取り扱いを述べる．また，主に窒素・酸素・アンモニア中の不純物測定についてまとめた．不純物成分としては，メタン・二酸化炭素・一酸化炭素・アルゴン・酸素・窒素・水などを取り上げ，各マトリックスガス中でのそれら不純物成分の検出下限について述べる．

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分析に利用可能な発光系を探索し，金属イオン定量のための新規化学発光試薬を明らかにした．それらはクマリンの誘導体であり，数種の入手可能な誘導体のなかでウンベリフェロンが最も高感度でMn(II)の定量が可能であることを示した．操作法はフローインジェクション分析法により，ウンベリフェロンとMn(II)イオンを含む試料溶液に過酸化水素溶液を加える2流路で行った．カチオン性界面活性剤であるセチルトリメチルアンモニウムブロミドを添加することで化学発光強度は著しく増大した．化学発光を示す金属イオンにはMn(II)のほかにCu，Coがあり，Fe，Pbなども微弱な発光を示した．比較的高い試薬空試験値は金属などの不純物によるものではなく，Mn(II)イオンの触媒効果とは異なった反応機構があるものと推定された．0～1000 pptの範囲で相関係数0.989の直線関係が得られ，検出限界は0.8 ppt，定量下限は2.4 pptであった．本法は河川水中のMn(II)の定量に適用された．

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ヨード強化卵（I卵）に含まれるヨウ化物イオン（I^－）を分析するため，I卵の卵黄0.05 g及び卵白0.5 gから，強陽イオン交換カートリッジ（Oasis MCX^®）及び弱陰イオン交換カートリッジ（Oasis WAX^®）を用いてI^－を固相抽出し，1 mLの分析試料を調製した．そして，この試料10 μLを紫外吸光検出法（検出波長: 225 nm）による逆相高速液体クロマトグラフィーで分析した．卵黄及び卵白中のI^－を繰り返し分析（n＝4）した場合の定量値の相対標準偏差は0.8及び5.5％ で，再現性は良好であった．また，卵黄1 g当たりに50 μg及び卵白1 g当たりに2.5 μgのI^－を添加して行った回収試験の回収率は92.4及び96.8％ で，正確度も良好であった．I^－の検出限界は，卵黄及び卵白各1 g当たり0.76及び0.08 μg（S/N＝3）であった．本分析法を用いて市販のI卵（n＝14）中のI^－の含量を調べた．

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In a qualitative test for urine protein by a test paper based on a protein error of tetrabromophenol blue, how the color development changes was examined by experiments and calculations when a pH change in the reaction mixture occurs in immersing a test paper in a urine sample whose pH may vary approximately from as low as 4.6 to as high as 7.8. In an experiment using bromophenol blue, the color development increased due to an increase in the pH of the reaction mixture, and the relative color intensity was closely associated with the magnitude of the pH change and the concentrations of the dye, buffer and protein. That is, even if the pH change by urine samples was equal, the relative color intensity differed with the concentrations of the dye, buffer and protein. It increased with an increase in the dye and buffer concentrations, and with a decrease in the protein concentration. These experimental results coincided well with those obtained by the calculation. It is important that the detection of a urine sample with a low protein concentration is carried out by using a test paper in which the dye concentration is low in order to suppress a false-positive result.

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For the purpose of marine environmental radioactivity monitoring, stable Cs and ¹³⁷Cs concentrations were obtained from 214 marbled flounder (Pleuronectes yokohamae) samples collected from off the coast of Ibaraki prefecture in Japan in 2005 and 2006. Prior to the investigation, an analytical method for the determination of Cs in muscle of marbled flounder samples by inductively coupled plasma mass spectrometry (ICP-MS) was seriously considered from the view point of sample preparation (wet way) to a Cs measurement. Since major problems in determining Cs by the ICP-MS is the interference of matrix materials and molecular ions on Cs peak area (m/z 133), a known amount of In (m/z 115) was added to the sample solutions as an internal standard. To check the accuracy of the determination, duplication analysis and standard reference materials were used. Analytical results of Cs in muscles samples by ICP-MS agreed well with duplicated samples, and standard reference materials. The standard length and body weight were obtained from a total of 214 flounder samples. The stable Cs, stable K and ¹³⁷Cs concentrations in muscle were determined by ICP-MS, flame photometry and radiochemical analysis, respectively. The mean standard length correlates closely with the mean body weight. The stable Cs concentration was in proportion to the body weight, also, the ¹³⁷Cs concentration correlated closely with the stable Cs concentration in muscle. On the other hand, a stable K concentration was found to be uniform, and unrelated with ¹³⁷Cs and stable Cs concentrations. The specific activities, the ratio of ¹³⁷Cs/stable Cs in muscle, was found to be 5.5∼6.7 with an average of 6.2±0.35 (SD) among five different size groups of the standard length of marbled flounder samples. From these results, ICP-MS provided useful tools for the determination of a trace amount of Cs in muscle samples, combined with wet way pretreatment techniques. In addition, marbled flounder proved to be a useful species for comparing the radioactivity of fishes in coastal seas around Japan with each other in the environmental radioactivity monitoring program.

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