Analytical Sciences
Online ISSN : 1348-2246
Print ISSN : 0910-6340
ISSN-L : 0910-6340
Volume 19 , Issue 11
Showing 1-21 articles out of 21 articles from the selected issue
Original Papers
  • Nariyasu MANO, Setsuko IIJIMA, Kie KASUGA, Junichi GOTO
    Type: scientific monograph
    Subject area: Infomation Science
    2003 Volume 19 Issue 11 Pages 1469-1472
    Published: 2003
    Released: March 31, 2004
    JOURNALS FREE ACCESS
    The utility of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) coupled with a peptide ladder sequencing method employing exopeptidase degradation for the analysis of phosphorylation site in a mono-phosphorylated peptide is investigated. MALDI-TOFMS analysis of time-dependent exopeptidase digestion using carboxypeptidase W and aminopeptidase M of the mono-phosphorylated 33-48 fragment isolated from a β -casein tryptic digestion mixture allowed for the sequencing analysis from both the C-terminus and N-terminus. Negative ion detection MALDI-TOFMS made it possible to clearly measure the peptide ladder of mono-phosphorylated peptide by the strong negative charge localized at the phosphoric acid group. Since exopeptidase activity was suppressed by the existence of a phosphorylated amino acid residue, the termination exopeptidase degradation therefore suggested the existence of a phosphorylated amino acid residue at that site. This peptide ladder sequencing method using exopeptidases was effective for the identification of the site of a phosphorylated amino acid residue by a simple MALDI-TOFMS analysis in the negative ion detection mode.
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  • Akira KOTANI, Yuji MIYAGUCHI, Dai HARADA, Fumiyo KUSU
    Type: scientific monograph
    Subject area: Infomation Science
    2003 Volume 19 Issue 11 Pages 1473-1476
    Published: 2003
    Released: March 31, 2004
    JOURNALS FREE ACCESS
    A disposable voltammetric cell using three pencil leads as working, reference, and counter electrodes was developed for determining the titratable acidity, i.e. the acid content in vinegar. The materials of the pencil leads were graphite-reinforcement carbons (GRCs). A voltammetric determination of acid was made by measuring the reduction prepeak current of 3,5-di-t-butyl-1,2-benzoquinone (DBBQ) due to the presence of acids in unbuffered solution. The potential stability of the pseudo-reference electrode of GRC was examined. The prepeak current was found to be proportional to the acetic acid concentration from 0.05 to 2.7 mM with a correlation coefficient of 0.999. The cell-to-cell reproducibility for 1 mM acetic acid was evaluated with ten individual disposable cells. The RSD of the prepeak current and the SD of the prepeak potential were 2.56% and 0.008, respectively. The titratable acidity in five vinegar samples was determined by voltammetry using disposable cells and compared with that of the titratable acidity determined by the conventional potentiometric titration method. We then observed the results by both methods, and found a correlation coefficient of 0.972. As such, the voltammetry using disposable-cell required only one thousandth the volume of a vinegar sample for the titration method. The disposable cell was superior to the conventional electrochemical cell, in terms of facility,environment-friendly, and economy, and thus a sensor using the present cell would be useful for routine work in the quality control of vinegar.
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  • Asha CHAUBEY, K. K. PANDE, B. D. MALHOTRA
    Type: scientific monograph
    Subject area: Infomation Science
    2003 Volume 19 Issue 11 Pages 1477-1480
    Published: 2003
    Released: March 31, 2004
    JOURNALS FREE ACCESS
    The electrochemical entrapment of polyaniline (PANI) onto sol-gel derived tetraethylorthosilicate (TEOS) films deposited onto indium-tin-oxide (ITO) coated glass has been utilized for immobilization of lactate dehydrogenase (LDH). The performance of these sol-gel/PANI/LDH electrodes has been investigated as a function of the lactate concentration, applied potential, pH of the medium and interferents. The amperometric response of the electrodes under optimum conditions exhibited a linear relationship from 1 mM to 4 mM. An attempt has been made to extend the linearity up to 10 mM for lactate by coating an external layer of polyvinyl chloride (PVC) over the sol-gel/PANI/LDH electrodes with a correlation coefficient of 0.89. These sol-gel/PANI/LDH electrodes have a response time of about 60 s, a shelf life of about 8 weeks at 0 - 4°C and have implications in a lactate biosensor.
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  • Sun Kil KANG, Ran-A JEONG, Sejin PARK, Taek Dong CHUNG, Sunmin PARK, H ...
    Type: scientific monograph
    Subject area: Infomation Science
    2003 Volume 19 Issue 11 Pages 1481-1486
    Published: 2003
    Released: March 31, 2004
    JOURNALS FREE ACCESS
    A new outer layer composition, consisting of polytetrafluoroethylene (PTFE), Kel-F oil, and Nafion, is suggested to minimize the detrimental effect of dissolved oxygen and to extend the linear response range of a glucose oxidase(GOx)-based sensor using nonconducting polymer. The morphology of Kel-F/PTFE/Kel-F/Nafion polymeric laminate was followed during fabrication by SEM. When Kel-F film was formed on the PTFE outer layer, the linear response was extended to 21 mM, at a sensitivity of 2.8 ± 0.8 nA/mM mm2. We demonstrate that a sensor without Kel-F/PTFE/Kel-F/ Nafion outer layer is relatively oxygen dependent, whereas by comparison a sensor with Kel-F/PTFE/Kel-F/Nafion outer layer is oxygen independent. The current of such a glucose sensor implanted in the subcutaneous tissue stabilized within 60 min, and the lag between blood glucose changes and sensor output was within 1 min. The in vivo characteristics of the glucose sensor described show great promise for one-point in vivo calibration.
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  • Linling WANG, Weihong HUANG, Xiumei SHAO, Xiaohua LU
    Type: scientific monograph
    Subject area: Infomation Science
    2003 Volume 19 Issue 11 Pages 1487-1490
    Published: 2003
    Released: March 31, 2004
    JOURNALS FREE ACCESS
    Alkaline water was used for the microwave-assisted extraction of some priority pollutants of phenols in sediments, i.e. phenol (Ph), 2-chlorophenol (2CP), 2,4-dichlorophenol (2,4DCP), 4-chlorophenol (4CP), 4-dinitrophenol (4NP) and pentachlorophenol (PCP). This organic solvent-free extraction procedure was optimized by studying the parameters such as pH, volume of the alkaline water, extraction pressure and time. Under the optimized conditions, the recoveries of phenols were in the range of 80% to 110%. The extracts were then cleaned-up and concentrated by microcolumn solid phase extraction (SPE) and determined by gas chromatography-flame ionization detection system. The relative standard deviation of the overall-method for most phenol determinations was about 5.0% (n = 6). The proposed method, which needs little volume (1 mL) of ethanol for SPE, has been applied to determine these phenols in sediment samples, and the analytical results are in good agreement with those achieved by Soxhlet extraction.
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  • Yaqi CAI, Guibin JIANG, Jingfu LIU
    Type: scientific monograph
    Subject area: Infomation Science
    2003 Volume 19 Issue 11 Pages 1491-1494
    Published: 2003
    Released: March 31, 2004
    JOURNALS FREE ACCESS
    A method for the determination of several phthalate esters in water samples using solid-phase extraction coupled to high-performance liquid chromatography was developed. A polytetrafluoroethylene turnings packed column was used as a SPE adsorbent material. The analytes were sorbed on polytetrafluoroethylene turnings, from which they were eluted by a small amount of acetonitrile, followed by a RP-HPLC-UV analysis. Detection limits (3σ) of 4.7, 3.1, 3.6, 4.3, and 5.8 ng mL-1 for di-n-butyl-phthalate, di-cyclohexyl-phthalate, di-n-octyl-phthalate, di-n-nonyl-phthalate and di-iso-decyl-phthalate, respectively, were achieved. Acceptable recovery results (92.1 - 127.5%) were obtained on five phthalate esters spiked samples.
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  • Jaroon JAKMUNEE, Yuthpong UDNAN, Richard MORRISON, Ronald BECKETT, Ian ...
    Type: scientific monograph
    Subject area: Infomation Science
    2003 Volume 19 Issue 11 Pages 1495-1498
    Published: 2003
    Released: March 31, 2004
    JOURNALS FREE ACCESS
    A simple low-cost flow-through light-scattering detector was developed for determining the particle mass concentration in colloidal suspensions. Employing a laser pointer as a light source and a photodiode IC as a light sensor, the detector was shown to have good sensitivity, yet was small and battery operated. The detector was demonstrated to be effective for the flow-injection nephelometric determination of sulfate by precipitation as barium sulfate.
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  • A. OUEJHANI, M. DACHRAOUI, G. LALLEVE, J. F. FAUVARQUE
    Type: scientific monograph
    Subject area: Infomation Science
    2003 Volume 19 Issue 11 Pages 1499-1504
    Published: 2003
    Released: March 31, 2004
    JOURNALS FREE ACCESS
    A method is introduced for recuperation of chromium(VI) in water samples by liquid-liquid extraction with tributylphosphate PO(C4H9O)3 (TBP) from acidic chloride media. The optimum conditions for quantitative extraction of Cr(VI) were evaluated by varying the experimental parameters, such as the shaking period, the pH of the aqueous phase, the hydrochloric acid concentration, the hydrogen and chloride ion concentrations, the extractant concentration and the ratio of aqueous-to-organic phase. The probable extracted species of hexavalent chromium in organic phase, deduced from log-log plots, were H2CrO4 in acid media in absence of chloride and HCrO3Cl in acidic chloride media. Chromium(VI) was found to be extracted with tributylphosphate from acidic chloride media according to the following reaction: HCrO4-(aq) + 2H+(aq) + Cl-(aq) + 2TBP(org) ⇔ [HCrO3Cl, 2TBP](org) + H2O(aq). Since the tributylphosphate (TBP) exhibited a high selectivity for chromium(VI), this method can be applicable to the extraction and the determination of chromium in both oxidation states {Cr(VI) and Cr(III)} in water samples.
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  • Mohammad Said HOSSEINI, Yousef NASERI
    Type: scientific monograph
    Subject area: Infomation Science
    2003 Volume 19 Issue 11 Pages 1505-1508
    Published: 2003
    Released: March 31, 2004
    JOURNALS FREE ACCESS
    A method for the trace amount determination of Tl(I), via its preconcentration, is proposed. The method is based on the reaction of iodide, Tl(I) and Rhodamine B in a weakly acidic medium. In this process an ion-associated complex is formed, which is floated at the interface of aqueous-cyclohexane layers. Various amounts of Tl(I) by a subsequent separation and dissolution of the floated complex in methanol could be determined, spectrophotometrically. Beer’s law was obeyed for the Tl(I) content in the range of (0.8 - 8.0) × 10-7 mol l-1 with a correlation coefficient of 0.9974. The conditional molar absorptivity was found to be 1.0 × 106 l mol-1 cm-1 at 560 nm, which indicated the considerable sensitivity of the procedure. The detection limit (DL) was 4.7 × 10-8 mol l-1 and the RSD (n = 5) for 4 × 10-7 mol l-1 of Tl(I) was 3.34%. None of the alkaline cations was interfered, and the interference of many other metal ions was eliminated via ion-exchange separation using a cation-exchanger resin, Amberlite IR-120, before the flotation step. The reliability of the procedure was confirmed by determining the Tl(I) contents of synthetic laboratory waste water by both flotation spectrophotometry and graphite furnace atomic absorption spectrometry (GFAAS). The recovery was 92.3 - 95.4% for 1 × 10-7 and 4 × 10-7 mol l-1, respectively. The precision and accuracy of the results were comparable via F and t tests at the 95% confidence level.
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  • Xiuli LIN, Wanguo HOU, Chenfu ZHU
    Type: scientific monograph
    Subject area: Infomation Science
    2003 Volume 19 Issue 11 Pages 1509-1512
    Published: 2003
    Released: March 31, 2004
    JOURNALS FREE ACCESS
    A cyclodextrin-modified micellar capillary electrophoretic method (MECC) was developed using mixtures of β-cyclodextrins (β-CD) and mono-3-O-phenylcarbamoyl-β-CD as chiral additives for the chiral separation of miconazole with the dual CDs systems. The enantiomers were resolved using a running buffer of 50 mmol/L borate pH 9.5 containing 15 mmol/L β-CD and 15 mmol/L mono-3-O-phenylcarbamoyl-β-CD containing 50 mmol/L sodium dodecyl sulfate and 1 mol/L urea. A study of the respective influence of the β-CD and the mono-3-O-phenylcarbamoyl-β-CD concentration was performed to determine the optimal conditions with respect to the resolution. Good repeatability of the method was obtained.
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  • Habibollah ESKANDARI, Ali GHANBARI SAGHSELOO
    Type: scientific monograph
    Subject area: Infomation Science
    2003 Volume 19 Issue 11 Pages 1513-1518
    Published: 2003
    Released: March 31, 2004
    JOURNALS FREE ACCESS
    1-(2-Pyridylazo)-2-naphthol (PAN) has been used for the simultaneous and individual determination of palladium and cobalt at trace levels. PAN complexes of palladium and cobalt at neutral pH form green-color neutral complexes, which are soluble in aqueous SDS micellar media. Under optimum conditions, calibration graphs for individual determinations by zero and first-derivative spectrophotometry, and also for simultaneous determinations by second-derivative spectrophotometry were obtained. A zero-crossing method using second-derivative spectrophotometry at 628 or 578 and 614 nm, respectively, for cobalt and palladium was used for simultaneous determinations. The method is able to determine the cobalt-to-palladium ratio, 5:1 to 1:10 (Wt/Wt), accurately. The accuracy and reproducibility of the determination method for various known amounts of cobalt and palladium in their binary mixtures were tested. The effects of diverse ions on the determination of cobalt and palladium to investigate the selectivity of the method were also studied. The recommended procedures were applied to a synthetic binary alloy, cobalt in vitamin B12 and B-complex ampoules, a Co2O3-Co3O4 laboratorial chemical mixture, some synthetic cobalt-alloy samples, a Pd-charcoal catalyst, and some synthetic palladium alloys.
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  • Paulo R. M. CORREIA, Cassiana S. NOMURA, Pedro V. OLIVEIRA
    Type: scientific monograph
    Subject area: Infomation Science
    2003 Volume 19 Issue 11 Pages 1519-1523
    Published: 2003
    Released: March 31, 2004
    JOURNALS FREE ACCESS
    A method for the multielement determination of cadmium and lead in urine is proposed by simultaneous electrothermal atomic absorption spectrometry (SIMAAS) with an end-capped transversely heated graphite atomizer (EC-THGA). The best conditions for cadmium and lead determination were obtained in the presence of NH4H2PO4 as a chemical modifier, using 500°C and 1800°C as the pyrolysis and atomization temperatures, respectively. Urine samples were diluted 1 + 4 directly in autosampler cups with a mixture of 0.125% (w/v) Triton X-100 + 2.5% (v/v) HNO3 + 0.31% (w/v) NH4H2PO4. The optimized heating program was carried out in 57 s, and the instrument calibration was done with aqueous reference solutions. The use of EC-THGA increased the sensitivity of cadmium and lead by 14% and 25%, respectively. The detection limits (n = 20, 3δ) were 0.03 μg L-1 (0.36 pg) for cadmium and 0.57 μg L-1 (6.8 pg) for lead. The performance of EC-THGA was acceptable up to 500 heating cycles. The reliability of the entire procedure was checked with the analysis of a lyophilized urine certified reference material. The found concentrations were in agreement with the recommended values (95% confidence level).
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  • Toshiaki HATTORI, Yasuko NAKATA, Ryo KATO
    Type: scientific monograph
    Subject area: Infomation Science
    2003 Volume 19 Issue 11 Pages 1525-1528
    Published: 2003
    Released: March 31, 2004
    JOURNALS FREE ACCESS
    The biguanide concentration of polyhexamethylene biguanide hydrochloride (PHMB-HCl) was measured by non-aqueous titration with HClO4, argentometric titration, the Kjeldhal method, and colloidal titration. The summation value of non-aqueous titration and argentometric titration corresponded to two titrable nitrogens in five nitrogens per one unit of PHMB-HCl, and consisted with the result of the Kjeldhal method to the five nitrogens. The colloidal titration of PHMB-HCl at pH 2.05 was equal to that with the two nitrogens. The relative standard deviations of non-aqueous titration, argentometric titration, the Kjeldhal method, and colloidal titration were 0.50% for 8 runs, 0.13% for 7 runs, 3.61% for 6 runs, and 0.69% for 6 runs, respectively.
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  • Kyoko TODA, Seiichi ISHIDA, Kotoko NAKATA, Rieko MATSUDA, Yukari SHIGE ...
    Type: scientific monograph
    Subject area: Infomation Science
    2003 Volume 19 Issue 11 Pages 1529-1535
    Published: 2003
    Released: March 31, 2004
    JOURNALS FREE ACCESS
    A traditional method for comparing two expression levels of genes in microarray experiments is the two-sample t-test. Because of the difficulty in using a large number of microarrays, an alternative method is required which can provide a reliable judgment of the comparison from a small number of replicates, even from a single pair of control and treatment. We present a method for detecting the changes in the gene expression levels under two different conditions in microarray experiments. Our method targets a single experiment for each condition, while retaining the statistical advantages of the t-test. The new proposals are: 1) standard deviation (SD) estimates of the expression levels which are an indicator for significant differences are given a priori as a function of the expression levels; 2) the limit of detection (LOD) for the expression levels is used to eliminate the majority of genes expressed at extremely low levels. The a priori SD estimates are obtained from six replicates under a fixed condition and are shown to be the approximate, but proper description of the expression uncertainty covering diverse conditions (e.g., different samples (human and rat) and different DNA chips). The LOD is defined as three times blank SD according to the IUPAC recommendation. A cell line (HL60) which will undergo macrophage differentiation on treatment with 12-O-tetradecanoylphorbol 13-acetate (TPA) is taken as an example. Our method is compared with the t-test for the data on duplicate TPA experiments and the former alone is evaluated with the data on a single TPA experiment. The errors from sample preparation and instrumental analysis are discussed.
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Notes
  • Libin SHANG, Ziyi SUN, Xingwu WANG, Genxi LI
    Type: scientific monograph
    Subject area: Infomation Science
    2003 Volume 19 Issue 11 Pages 1537-1539
    Published: 2003
    Released: March 31, 2004
    JOURNALS FREE ACCESS
    Hemoglobin can exhibit not only a direct electron transfer reacting after being entrapped in a DNA membrane, but also a greatly enhanced peroxidase activity toward the reduction of hydrogen peroxide. Based on the direct electrochemical property and nice enzymatic activity of the protein in a DNA membrane, a reagentless hydrogen peroxide biosensor was prepared. The peak current related to hydrogen peroxide was linearly proportional to its concentration in the range of 1.9 × 10-6 -6.8 × 10-4 mol L-1. The detection limit was 1 × 10-6 mol/L.
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  • Xing-Zheng WU, Kasanori KASASHIMA, Masahiko SAKAI
    Type: scientific monograph
    Subject area: Infomation Science
    2003 Volume 19 Issue 11 Pages 1541-1543
    Published: 2003
    Released: March 31, 2004
    JOURNALS FREE ACCESS
    A hollow fiber sampling inlet end of capillary electrophoresis (CE) for small ions in complex samples is described. A short piece of hollow fiber, which only permits small ions to pass through its wall, was directly connected to one end of a capillary. Small ions in complex samples were injected into the capillary through the hollow fiber by an electrokinetic method. The experimental results of CE for standard anion mixture solutions, river water, and milk samples show that the hollow fiber sampling inlet end is a simple and useful method for the CE of complex samples. Furthermore, it has been shown that the method can be used to study small anion changes during the milk storing process.
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  • Hiroshi UCHIHARA, Masahiko IKEDA, Taketoshi NAKAHARA
    Type: scientific monograph
    Subject area: Infomation Science
    2003 Volume 19 Issue 11 Pages 1545-1547
    Published: 2003
    Released: March 31, 2004
    JOURNALS FREE ACCESS
    This paper describes a method for removing oxide film from the surface of silicon wafers using an inert gas fusion impulse furnace and precise determination of bulk oxygen within the wafer. A silicon wafer was cut to about 0.35 g (6 × 13 × 2 mm) and dropped into a graphite crucible. The sample was then heated for 40 s at 1300°C. The wafer’s oxide film was reduced by carbon and removed as carbon monoxide. The treated silicon sample was taken out of the graphite crucible and maintained again with the holder of the oxygen analyzer. The graphite crucible was then heated to 2100°C. The treated silicon sample was dropped into the heated graphite crucible and the trace bulk oxygen in the wafer was measured using the inert gas fusion infrared absorption method. The relative standard deviations of the oxygen in silicon wafer samples with the removed surface oxide film were determined to be 0.8% for 9.8 × 1017 atoms/cm3, and 2.7% for 13.0 × 1017 atoms/cm3.
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  • Habibollah ESKANDARI, Gholam Hassan Imanzadeh KARKARAGH
    Type: scientific monograph
    Subject area: Infomation Science
    2003 Volume 19 Issue 11 Pages 1549-1552
    Published: 2003
    Released: March 31, 2004
    JOURNALS FREE ACCESS
    α-Benzilmonoxime in sodium dodecylsulfate micellar media has been used for the spectrophotometric determination of cobalt at pH 9.0. The linear range of calibration is 0.05 - 1.50 μg cm-3 of cobalt at 380 nm with molar absorptivity of 3.72 × 104 dm3 mol-1 cm-1, which is about 1.5-times greater than that of the α-benzilmonoxime extraction based method. The relative standard deviations, recoveries, detection limit and effects of diverse ions on the determination of cobalt were studied. These analytical results were satisfactory. The method was successfully applied to the determination of cobalt in the various samples.
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  • Masanori KUMAGAI, Naganori OHISA, Toshio AMANO, Nobuaki OGAWA
    Type: scientific monograph
    Subject area: Infomation Science
    2003 Volume 19 Issue 11 Pages 1553-1555
    Published: 2003
    Released: March 31, 2004
    JOURNALS FREE ACCESS
    Near-infrared analysis (NIRA) was applied to discriminate and determine the cadmium content levels of unpolished rice using canonical discriminant analysis (CDA). The overall correct classification rate was 85.2% for 318 NIR spectra, repeated three times for 106 samples. After a further improvement through decreased misclassification rates, NIRA could be useful as a rapid, nondestructive and convenient analytical method for primary screening and detecting of cadmium-polluted rice.
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  • Akihito SHINOZAKI, Kenta ARIMA, Mizuho MORITA, Isao KOJIMA, Yasushi AZ ...
    Type: scientific monograph
    Subject area: Infomation Science
    2003 Volume 19 Issue 11 Pages 1557-1559
    Published: 2003
    Released: March 31, 2004
    JOURNALS FREE ACCESS
    The effectiveness of cleaning organic contaminants from silicon dioxide (SiO2) surfaces was studied by conducting highly sensitive measurements using Fourier Transform Infrared Attenuated Total reflectance (FTIR-ATR) with a Si prism as the waveguide. To serve as an example, the surface of the prism was oxidized to an order of a few nanometers. The oxidized Si surface film was allowed to stand in the atmosphere and then wet-cleaned in a repeated manner; subsequently its thickness was measured by ellipsometry. Although, various wet-cleaning methods were tested, they only showed values of 0.1 - 0.2 nm larger than, but not equal to, the original thickness immediately after oxidation. FTIR-ATR measurements of the spectral change after exposure to air revealed that organic species, such as C-CH3 and -(CH2)n-, increased with time. Wet-cleaning the sample failed to remove the C-CH3 species, which indicates that they corresponded to the film thickness increment from the original.
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  • Kyue-Hyung LEE, Koji OSHITA, Akhmad SABARUDIN, Mitsuko OSHIMA, Shoji M ...
    Type: scientific monograph
    Subject area: Infomation Science
    2003 Volume 19 Issue 11 Pages 1561-1563
    Published: 2003
    Released: March 31, 2004
    JOURNALS FREE ACCESS
    A simple method to estimate the amounts of ultra-trace metal impurities in nitric acid reagents has been developed. The determination of sixty-four metals in nitric acid was accomplished by direct measurements of 0.1 M nitric acids accurately diluted with ultrapure water by ICP-MS. Though accurate metal concentration could not be obtained for all of the elements, we could effectively evaluate the nitric acid quality by comparing the ion counts of the samples, ultrapure water and standard metal solutions for a calibration prepared with UltrapurTR nitric acid.
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