Hideo Iwata

Application of slurry nebulization to trace elemental analysis of some biological samples by inductively coupled plasma mass spectrometry

SummaryThe application of slurry nebulization/inductively coupled plasma mass spectrometry (ICP-MS) to trace elemental analysis of biological samples has been investigated. Three standard samples of the National Institute of Standards and Technology (NIST) were dispersed in 1% aqueous Triton X-100 solution by grinding with a planetary micronizing mill. The resulting slurries were nebulized into an ICP without any additional treatments. The 1% (m/v) slurry of the NIST bovine liver showed no significant influence on cone blockage and signal suppression/enhancement. Detection limit, precision and accuracy were discussed for the determination of 24 elements of interest in bovine liver, rice flour and pine needles. Detection limits ranged from 0.0001 μg g−1 for U to 0.52 μg g−1 for Zn at the effective integrating time of 10 s. For high mass elements, low blank values were obtained, yielding excellent limits (<0.01 μg g−1). Acceptable accuracy and precision were obtained for most of the elements in the NIST bovine liver and rice flour, even for the volatile elements, such as As, Se and Br. However, relatively poor accuracy was obtained for the analysis of pine needles.

Correction method for X-ray fluorescent determination of chromium in high-alloy steels and nickel-base alloys

ZusammenfassungDie Eich-Gleichung für das neue Korrekturverfahren wurde vom JIS-Modell (Japanese Industrial Standards) abgeleitet und ist über einen weiten Bereich von Zusammensetzungen durch Herstellung von lediglich binären Fe-Cr-Standards einsetzbar. Das beschriebene Verfahren bietet eine bessere Genauigkeit als die Methode nach dem Korrekturmodell von Rasberry-Heinrich. Sie betrug 0,08% für hochlegierte Stähle und 0,14% für Nickellegierungen.SummaryA new interelement correction method has been developed for the X-ray fluorescent determination of chromium in high-alloy steels and nickel-base alloys. The calibration equation which was derived from the JIS (Japanese Industrial Standards) model is applicable over wide ranges of compositions by preparation of only Fe-Cr binary standards.The new approach gave better accuracy than that based on Rasberry-Heinrich correction model. The accuracies (σd) were 0.08% for high-alloy steels and 0.14% for nickel-base alloys.

Determination of trace amount of sulfur in high-purity iron by coulometric titration after high-frequency combustion.

高周波燃焼/電量滴定法による高純度鉄中の微量硫黄定量方法について検討した.すなわち燃焼ガス流量の影響,助燃材の影響,試料量の影響及び硫黄の二酸化硫黄としての回収率を求めて分析条件を決定した.高純度鉄中の硫黄を本法で定量したところ1ppm程度の硫黄が精度よく分析可能であった.又,検出下限は0.23μgであった.更に他分析方法と分析精度も比較した.

Quantitative determination of carbon in steel by acid decomposition/nonaqueous titrimetry.

鉄鋼試料を硫酸と過酸化水素で分解し,発生する二酸化炭素を2-アミノエタノールを含むジメチルホルムアミド溶液に吸収させた後,テトラブチルアンモニウムヒドロキシドで滴定する方法を検討した.酸分解によって二酸化炭素と同時に各種の炭化水素が発生する.これは鉄と酸との反応によって生ずる水素(プロトン)によって炭素が水素化されて生ずるものと考えられる.共存する硫黄が高値を示す原因となるが,活性二酸化マンガンによって除去可能であった.炭素5μgまでは良好な精度で分析可能であった.日本鉄鋼標準試料を分析した結果,相対標準偏差1%前後で定量できた.