共查询到20条相似文献,搜索用时 31 毫秒
1.
ET-AAS is investigated for the analysis of high purity mercury. Two possibilities are proposed: ET-AAS determination of trace analytes in the presence of high mercury concentrations or after matrix separation by reduction. The ET-AAS analysis of high-purity mercury under optimal instrumental parameters permits fast and reproducible determination of 0.03 gg–1 Al, Cd and Mn; 0.05 gg–1 Cu, Co, Cr, Fe, Ni and Pb and 0.2 gg–1 V. Preliminary mercury matrix reductive separation with ascorbic acid allows determination of 0.005 gg–1 Cd, 0.02 gg–1 Cu, Cr and Mn, 0.03 g g–1 Co, Ni and Pb, 0.05 g g–1 Al and Fe and 0.1 gg–1 V, but the reproducibility is lower. The main advantage of the second procedure is that it avoids laboratory and instrument pollution with toxic mercury. 相似文献
2.
J. Flores-Pérez C. Flores-Pérez H. Juárez-Olguín I. Lares-Asseff M. Sosa-Macías 《Chromatographia》2004,59(7-8):481-485
The aim of the present study was to develop a sensitive method to measure dextromethorphan and dextrorphan in urine by HPLC to support pharmacogenetic studies in ethnic groups. Linearity was assessed in the range: 0.015–10 g mL–1 for dextromethorphan and 1-10 g mL–1 for dextrorphan. Inter and intra-day coefficients of variation were < 10%. Limits of detection and quantitation were 0.003 g mL–1 and 0.015 g mL–1 for dextromethorphan and 0.24 g mL–1 and 1.0 g mL–1 for dextrorphan, respectively. The method is reliable in helping determine the phenotype of Mexican ethnic groups using model drugs such as dextromethorphan. 相似文献
3.
Determination of pyrimethanil and kresoxim-methyl in soils by headspace solid-phase microextraction and gas chromatography-mass spectrometry 总被引:1,自引:0,他引:1
Navalón A Prieto A Araujo L Vílchez JL 《Analytical and bioanalytical chemistry》2004,379(7-8):1100-1105
A method using headspace solid-phase microextraction (HS-SPME) then gas chromatography–mass spectrometry with selected ion monitoring (GC–MS, SIM) has been developed for determination of trace amounts of the fungicides pyrimethanil and kresoxim-methyl in soil and humic materials. Both fungicides were extracted on to a fused-silica fibre coated with 85 m polyacrylate (PA). Response-surface methodology was used to optimise the experimental conditions. For soil samples the linear dynamic range of application was 0.004–1.000 g g–1 for pyrimethanil and 0.013–1.000 g g–1 for kresoxim-methyl. The detection limits were 0.001 g g–1 and 0.004 g g–1 for pyrimethanil and kresoxim-methyl, respectively. HP-SPME–GC–MS analysis was highly reproducible—relative standard deviations (RSD) were between 6.7 and 12.2%. The method was validated by analysis of spiked matrix samples and used to investigate the presence of pyrimethanil and kresoxim-methyl above the detection limits in soil and humic materials. 相似文献
4.
M. Vobecký 《Journal of Radioanalytical and Nuclear Chemistry》1989,135(3):171-176
The interference contributions of uranium and thorium to the determination of cerium based on radionuclides141Ce and143Ce produced by irradiation in a reactor core was determined. The values of the interference contributions for141Ce were 0.28±0.01 g Ce/g U and /2.01±0.05/x10–3 g Ce/g Th, and for143Ce 1.33±0.03 g Ce/g U and /9.0±0.2/x10–3 g Ce/g Th. 相似文献
5.
A. Youssef El-Sayed 《Fresenius' Journal of Analytical Chemistry》1996,355(1):29-33
First- and second-derivative spectrophoto-metric methods for the simultaneous determination of aluminium and iron in their mixtures are described. The methods are based on the colored complexes formed by aluminium and iron with hematoxylin in the presence of cetyltrimethylammonium bromide as a surfactant. The zero-crossing method has been utilized to measure the first- and second-derivative value of the derivative spectrum. Aluminium (0.05–1 gml-1) could be determined in the presence of iron (0.09–1.6 gml-1) and vice versa. The detection limits of aluminium and iron are 0.01 and 0.09 gml-1, respectively in the first-derivative mode and 0.014 and 0.1 gml-1 in the second-derivative mode. The proposed method has been applied to the simultaneous determination of aluminium and iron in glasses, phosphate rocks, cement and magnesite alloy. 相似文献
6.
A -mercaptopropionic acid (MPA) self-assembled monolayer modified electrode (MPA/SAM/Au) on a gold electrode has been fabricated. The characterization of the MPA/SAM/Au was investigated using attenuated total reflection-fourier transform infrared (ATR-FTIR) and A.C. impedance. The electrochemical behaviors of p-aminophenol (p-AP) were studied at the MPA/SAM/Au by cyclic voltammetry and semi-derivative voltammetry (SDV) in BR buffer solution. The modified electrode shows excellent electrocatalytic activity for the redox of p-AP and accelerates the electron transfer rate. The diffusion coefficient (D) is 4.55×10–6cm2s–1. The oxidative peak current increases linearly with the concentration of p-AP in the range of 4.0×10–88×10–6molL–1 and 1.0×10–52×10–4molL–1 by square wave voltammetry response, respectively. The detection limit (three times the signal blank/slope) is up to 1.2×10–8molL–1. The modified electrode is able to eliminate the interference of p-benzenediol, o-benzenediol and o-AP at a 40-, 90- or 70-fold concentration of p-AP, and it has been satisfactorily used for the determination of the real sample. 相似文献
7.
Application of l-cysteine-capped nano-ZnS as a fluorescence probe for the determination of proteins 总被引:1,自引:0,他引:1
Zhu CQ Zhao DH Chen JL Li YX Wang le Y Wang L Zhou YY Zhuo SJ Wu YQ 《Analytical and bioanalytical chemistry》2004,378(3):811-815
Nanometer-sized l-cysteine-capped ZnS particles have been synthesized and used as a fluorescence probe to investigate the effect of proteins on fluorescent intensity. With =190 nm, maximum and constant synchronous fluorescence enhancement was produced at 267 nm and pH 5.12 in the presence of proteins. A highly sensitive synchronous fluorescence method for the rapid determination of proteins has been developed. Under optimum conditions, calibration graphs are linear over the range 0.03–8.0 g mL–1 for bovine serum albumin (BSA), 0.01–6.0 g mL–1 for human serum albumin (HSA), 0.05–8.0 g mL–1 for -globulin (-G), and 0.04–4.0 g mL–1 for ovalbumin, respectively. The relative standard deviations of seven replicate measurements were 1.75% for 1.0 g mL–1 BSA, 1.90% for 1.0 g mL–1 HSA, 1.65% for 1.0 g mL–1 -G, and 2.32% for 1.0 g mL–1 ovalbumin. 相似文献
8.
The effect of cationic surfactants (cetyltrimethylammonium bromide, cetylpyridinium bromide, and tetrabutylammonium perchlorate) and a nonionic surfactant (OP-7) on the conditions of the immobilization of 4-(2-pyridylazo)resorcinol (PAR) on three types of silica gel (Silochrom S-120 (200–350 m), Silochrom S-120 (315–500 m), and Silochrom S-80 (200–350 m)) was studied. It was found that OP-7 does not affect the adsorption of surfactants. The effect of cationic surfactants increases in the order tetrabutylammonium perchlorate < cetyltrimethylammonium bromide < cetylpyridinium bromide. The adsorption activity of silica gels increases in the order Silochrom S-120 (315–500 m) < Silochrom S-80 (200–350 m) < Silochrom S-120 (200–350 m). Cetylpyridinium bromide provides full immobilization of PAR on silica gel Silochrom S-120 (200–350 m) in the pH range 2–9. 相似文献
9.
Hartwig Möller Nikolaus Seiler und Gottfried Werner 《Fresenius' Journal of Analytical Chemistry》1968,243(1):126-129
Zusammenfassung Es werden Erfahrungen mit der Kombination von automatischem Aminosäurenanalysator und Szintillations-Durchflußzelle zur Bestimmung der spezifischen Radioaktivität 14C-markierter Aminosäuren im Gehirn mitgeteilt. Die Erfassungsgrenze beträgt 3 · 10–4 Ci/ml Eluat, die Reproduzierbarkeit 5–1% vom Mittelwert im Meßbereich von 1 · 10–3 bis 5 · 10–2 Ci.
A method for the determination of the specific radioactivity of free amino-acids in tissue extracts of mammals
Some experiences are given with a measuring device for the determination of the specific radioactivity of 14C-labelled brain amino-acids. The apparatus consists of an automatic amino-acid analyzer combined with a flow cell filled with anthracene. The reproducibility of the method is ±5% to ±1% m.e. in the range of 1×10–3 Ci to 5×10–2 Ci. A quantitative determination of 3×10–4 Ci/ml eluant is still possible.相似文献
10.
Summary Two packing materials, C18 and PLRP-S, are studied for on-line trace enrichment of phenolic compounds in water. Various precolumns of different internal diameter are also tested and the addition of an ion-pair reagent to increase retention and thus, breakthrough volumes of phenolic compounds, is studied. Best results are obtained when a PLRP-S precolumn is coupled on-line with a C18 analytical column and DAD detector. Addition of TBA considerably increases breakthrough volumes. In contrast, when a C18 precolumn is used, breakthrough volumes are lower and it is impossible to determine TCP and PCP, under the experimental conditions used, because of interference of other nonpolar compounds in the samples. The performance of the system is evaluated with river and tap water and the preconcentration of 10 ml of sample in a PLRP-S precolumn involves a linear range between 1 g 1–1 and 20 l–1 and limits of determination between 0.5 g l–1 and 1 g l–1 are obtained. 相似文献
11.
Zusammenfassung Eine neue Methode zur Durchführung gravimetrischer Bestimmungen im Mikrogrammbereich wurde beschrieben; diese beruht im wesentlichen darauf, daß der Niederschlag nicht mehr zusammen mit dem Filter, sondern nach Überführen mit einem geeigneten Lösungsmittel in einem separaten Wägegefäß gewogen wird.Die dazu nötigen Geräte und deren Herstellung wurden beschrieben. Nach dieser Methode wurden folgende Bestimmungen mit zufriedenstellender Richtigkeit durchgeführt: 2,5–25g Al, 5–50g Cu und 5–50g Zn mit Oxin, 2,5–25g Fe(III) und 2,5–25g Ti(IV) mit N-Benzoyl-phenylhydroxylamin, 5–50g Ni und 5–50g Cu mit Salicylaldoxim, 2,5–50g Co(II) und 2,5–50g Fe(III) mit -Nitroso--naphthol sowie 5–50g Chlorid als Silberchlorid.
Precipitation analysis in the microgram-scale: A new method
Summary A new method for gravimetric determinations in the microgram-scale is described. This method is based on the fact that the precipitate is not weighed together with the filter but is transferred to a separate weighingvessel using a suitable solvent. The necessary simple devices and their use are described. The following determinations were carried out with satisfying accuracy: 2,5–25g Al, 5–50g Cu and 5–50g Zn with Oxine, 2,5–25g Fe and 2,5–25g Ti withN-benzoylphenylhydroxylamine, 5–50g Ni and 5–50g Cu with salicylaldoxime, 2,52–50g Co and 2,5–50g Fe with -nitroso--naphthol and 5–50g chloride as silver chloride.相似文献
12.
Platinum concentration in silicone breast implant material and capsular tissue by ICP-MS 总被引:2,自引:0,他引:2
Maharaj SV 《Analytical and bioanalytical chemistry》2004,380(1):84-89
Inductively coupled plasma-mass spectrometry (ICP-MS) was used to determine the concentration of platinum (Pt) in silicone breast implant gel (range, 0.26–48.90 g g–1 Pt; n=15), elastomer (range, 3.05–28.78 g g–1 Pt; n=7), double lumen (range, 5.79–125.27 g g–1 Pt; n=7), foam (range, 5.79–8.36 g g–1 Pt; n=2), and capsular tissue (range, 0.003–0.272 g g–1 Pt; n=15). The results show that very high levels of Pt are present in the encasing elastomer, double lumen, and foam envelope materials. Silicone breast implants can be a source of significant Pt exposure for individuals with these implants. 相似文献
13.
Furusawa N 《Analytical and bioanalytical chemistry》2004,378(8):2004-2007
A method for the determination of aldrin, dieldrin, DDT, DDE, and DDD contamination in animal fats (beef tallow, lard, and chicken fat) without using toxic reagents is developed, that uses high-performance liquid chromatography after the sample has been prepared by matrix solid-phase dispersion (MSPD) with acidic alumina oxide. A reversed-phase C1-silica column with a mobile phase of 50% (v/v) ethanol solution (in water) and a photo-diode array detector were used for the determination. Average recoveries of the target compounds (0.2–5.0 g g–1) ranged from 84–98%, with coefficients of variation of <5%. The limits of quantitation were 0.16 g g–1 for AD, 0.10 g g–1 for DD, 0.06 g g–1 for DDT, 0.07 g g–1 for DDE, and 0.05 g g–1 for DDD. No toxic reagents were used at all. 相似文献
14.
P. J. Rennie 《Chromatographia》1988,26(1):297-299
Summary A method is proposed for the determination of 2-mercaptobenzothiazole in river waters using multi-electrode electrochemical detection HPLC. 2-mercaptobenzothiazole determination is unsatisfactory by gas chromatography as it degrades readily on the column. Multielectrode electrochemical detection HPLC combines sensitivity and the ability to screen out other electrochemically active species. The development work leading up to the proposed method is discussed. The method has a limit of detection of 0.798gl–1 2-mercaptobenzothiazole and a total standard deviation of 2.06gl–1 2-mercaptobenzothiazole at a concentration of 7.97gl–1 2-mercaptobenzothiazole in river water. 相似文献
15.
Spectrofluorimetric determination of nucleic acids as 8-hydroxyquinoline/ yttrium ternary complexes 总被引:1,自引:0,他引:1
The formation of nucleic acids/8-hydroxyquinoline/yttrium(III) ternary complexes and their fluorescent properties have been studied. The nucleic acids studied include native and thermally denatured calf thymus DNA, fish sperm DNA and yeast RNA. In the range of pH 7.6–8.5, controlled by NH3-NH4C1 buffer, ternary complexes are formed that fluoresce at different wavelengths with different nucleic acids. Based on the fluorescence reactions, sensitive spectrofluorimetric methods for nucleic acids are proposed. In optimal conditions, the calibration curves were linear in the range 0.5–4.0 gml–1 for calf thymus DNA, 0.5–2.5 g ml–1 for fish sperm DNA and 0.5–4.0 g ml–1 for yeast RNA. The limits of determination (3 ) were 0.030 g ml–1 for calf thymus DNA, 0.020 g ml–1 for fish sperm DNA and 0.090 g ml–1 for yeast RNA. Corresponding to the interferences of coexisting substances, six synthetic samples were constructed and the results of determination were satisfactory. 相似文献
16.
A method for the determination of triphenyltin and diphenyltin was developed by reversed-phase high-performance liquid chromatography with UV detection. Triphenyltin and diphenyltin were separated using a reversed-phase Symmetry C18 column (150 × 3.9 mm, 5 m) with tetrahydrofuran-water-acetonitrile-glacial acetic acid (13:25:5:7, v/v) containing 0.05% triethylamine and 1.0% sodium acetate as mobile phase at 0.50 mL min–1 and detection at 257 nm. The calibration curves were linear from 0.26 mol L–1 to 1100 mol L–1 for triphenyltin with a correlation coefficient of 0.9999 (n=12) and from 0.60 mol L–1 to 1200 mol L–1 for diphenyltin with a correlation coefficient of 0.9991 (n=12), respectively. The detection limits of triphenyltin and diphenyltin were 0.2 mol L–1 and 0.4 mol L–1, respectively. The method was successfully applied to the determination of triphenyltin and its metabolite diphenyltin in culture medium. The recoveries of triphenyltin and diphenyltin were in the ranges of 97.7% to 103.3% and 85.5% to 91.6%, respectively. 相似文献
17.
A new method is proposed for simultaneous determination of traces of arsenic (As) and selenium (Se) in biological samples by hydride-generation double-channel non-dispersive atomic-fluorescence spectrometry (HG-AFS) from tartaric acid media. The effects of analytical conditions on fluorescence signal intensity were investigated and optimized. Interferences from coexisting ions were evaluated. Under optimum conditions linear response ranges above 20 g L–1 for As and 32 g L–1 for Se were obtained with detection limits of 0.13 and 0.12 g L–1, respectively. The precision for elevenfold determination of As at the 4 g L–1 level and of Se at the 8 g L–1 level were 2.7 and 1.9% (RSD), respectively. Recoveries of 92.5–95.5% for As and 101.2–108.4% for Se were obtained for four biological samples and two certified biological reference materials. The proposed method has the advantages of simple operation, high sensitivity, and high efficiency; it was successfully used for simultaneous determination of As and Se in biological samples. 相似文献
18.
Soichi Nadahara Tadashi Kikuchi Keiichi Furuya Shiro Furuya Kiyoshi Hoshino 《Mikrochimica acta》1985,85(3-4):157-166
Summary Laser microprobe mass analysis (LAMMA) was applied to characterize aerosol particles collected and separated from 16m to 0.06m by a low pressure cascade impactor. Positive ion LAMMA spectra showed characteristic molecular peaks such as PbCl+, a series of Si2O+–Si2O4
+ and NaAl2Si2O2
+–NaAl2Si2O5
+, and TiO+ in 0.06–0.12m, 0.5–1m and 4–8m fraction, respectively. In the negative ion LAMMA spectra, it was observed that the fragment peaks of sulfate ions were deficient above 2m and those of nitrate ions were deficient under 2m. LAMMA allows remarkable insights into the chemical nature of aerosol particles.
Charakterisierung luftgetragener Teilchen durch Laser-Microprobe-Massenspektrometrie
Zusammenfassung Laser-Microprobe-Spektrometrie (LAMMS) wurde zur Analyse atmosphärischen Aerosols herangezogen, welches im Korngrößenbereich zwischen 16m und 0.06m mit einem Niederdruckkaskadenimpaktor fraktioniert gesammelt wurde. Positive LAMMS-Spektren zeigten charakteristische molekulare Peaks, wie etwa PbCl+, eine Serie von Si2O+–Si2O4 + und NaAl2Si2O2 +–NaAl2Si2O5 +, sowie TiO+ in der 0,06–0,12-m,- 0,5–1–m- bzw. 4–8-m-Fraktion. In den negativen LAMMS-Spektren konnten über 2m keine Fragmentpeaks für Sulfationen, unter 2m. keine für Nitrationen beobachtet werden. LAMMS ermöglicht eine bemerkenswerte Einsicht in die chemische Natur von Aerosolteilchen.相似文献
19.
G. Popa F. M. Albert und E. Radulescu-Grigore 《Fresenius' Journal of Analytical Chemistry》1965,207(5):346-347
Zusammenfassung Es wird eine photometrische Bestimmungsmethode beschrieben für Anilin (40–720 g/ml), Monoäthylanilin (90–1650 g/ml) und Diäthylanilin (100–1600 g/ml) mit Natriumchlorit in äthanolisch-wäßrigen Lösungen, sowie für Diäthylanilin (85–1140 g/ml) und Dimethylanilin (30–330 g/ml) neben den primären und sekundären Aminen in essigsaurer Lösung mit demselben Reagens. Das Verfahren liefert gute Ergebnisse.
Summary A photometric procedure is described for the determination of aniline (40–720 g/ml), monoethylaniline (90–1650 g/ml), and diethylaniline (100–1600 g/ml) with sodium chlorite in aqueous ethanolic solutions and of diethylaniline (85–1140 g/ml) and dimethylamline (30 to 330 g/ml) in presence of the primary and secondary amines in acetic acid solution using the same reagent. Good results have been obtained,相似文献
20.
Halina Sikorska-Tomicka 《Fresenius' Journal of Analytical Chemistry》1968,234(6):414-417
Zusammenfassung 2-Thiobarbitursäure wird zum Nachweis und zur Bestimmung von Fe(III) verwendet. Im Reagensglas kann noch 1 g Fe(III)/ml nachgewiesen werden. Eine größere Empfindlichkeit (0,2 g/ml) wird bei Anwendung eines mit Thiobarbitursäurelösung getränkten Papiers erreicht. Die photometrische Bestimmung ist im Konzentrationsbereich 4–40 g/ml mit einem Fehler von höchstens ±0,5 g möglich.
Summary 2-Thiobarbituric acid is recommended for the detection and determination of trivalent iron. In the test tube 1 g of Fe(III)/ml can be detected, whereas this limit can be reduced to 0.2 g of Fe(III)/ml by use of paper impregnated with the reagent. The photometric determination is possible within the range of 4–40 g of Fe(III)/ml with an error of not more than ±0.5 g.相似文献