共查询到20条相似文献,搜索用时 31 毫秒
1.
V. Zaichick 《Journal of Radioanalytical and Nuclear Chemistry》2007,271(3):573-576
The effect of age and sex was investigated on the concentration of chemical elements in intact cancellous bone of iliac crest
of 74 relatively healthy, 15–55 years old women (n = 29) and men (n = 45). Concentrations of Ca, Cl, K, Mg, Mn, Na, P, and Sr in bone samples were determined by instrumental neutron activation
analysis using short-lived radionuclides. Mean values (M±S.E.M.) of the mass fraction of the investigated elements (on dry
weight basis) for female and male all together were: 127±4 g/kg, 1620±80 mg/kg, 1310±70 mg/kg, 1550±50 mg/kg, <0.32±0.02 mg/kg,
4240±110 mg/kg, 61.8±1.8 g/kg, and 235±18 mg/kg, respectively. The statistically significant (≤0.05) decrease of Ca, Mg, and
P concentrations in the iliac cancellous bone with age was found only for women. Sex-related comparison has shown that the
mean values of Mg mass fractions in male bone samples were less than in female ones. 相似文献
2.
Li Shunxin Qian Shahua Huang Ganquan He Fei 《Fresenius' Journal of Analytical Chemistry》1999,365(5):469-471
A novel method for the separation and preconcentration of Se(IV)/ Se(VI) with algae and determination by graphite furnace
atomic absorption spectrometry (GFAAS) has been developed. The Se(VI) is extracted with algae from the solution containing
Se(IV)/Se(VI) at pH 5.0, and the remaining Se(IV) is then preconcentrated pH 1.0. The detection limits (3σ, n = 11) of 0.16 μg L–1 for Se(IV) and 0.14 μg L–1 for Se(VI) are obtained using 40 mL of solution. At the 2.0 μg L–1 level the relative standard deviation is 2.6% for Se(IV) and 2.3% for Se(VI). The method has been applied to the determination
of Se(IV)/Se(VI) in sediment and water samples. Analytical recoveries of Se(IV) and Se(VI) added to samples are ?97 ± 5% and
102 ± 6% (95% confidence), respectively.
Received: 10 February 1999 / Revised: 21 June 1999 / /Accepted: 22 June 1999 相似文献
3.
Sayed Zia Mohammadi Daryoush Afzali Davood Pourtalebi 《Journal of Analytical Chemistry》2011,66(7):620-625
In this article, a sensitive cloud point extraction procedure for the preconcentration of trace amounts of palladium, gold
and nickel prior to their determination by flame atomic absorption spectrometry has been developed. The cloud point extraction
method is based on the complexation of Pd(II), Au(II), and Ni(II) ions with 1-(2-pyridylazo)-2-naphthol and entrapping in
non-ionic surfactant Triton X-114. The main factors affecting cloud point extraction efficiency, such as pH of sample solution,
concentration of 1-(2-pyridylazo)-2-naphthol and Triton X-114, equilibration temperature and time, were investigated in detail.
Under the optimized conditions, calibration curves were constructed for the determination of palladium, gold and nickel according
to the general procedure. Linearity was maintained from 0.01 to 1.0 μg/mL for palladium, 10.0 μg/mL to 1.5 μg/mL for gold,
and 10.0 μg/mL to 0.5 μg/mL for nickel. Detection limits based on three times the standard deviation of the blank divided
by the slope of analytical curve (3Sb/m) for Pd(II), Au(III), and Ni(11) ions were 3.4, 3.9, and 2.4 μg/mL, respectively.
Seven replicate determination of a mixture of 0.5 μg/mL palladium and gold and 0.2 μg/mL nickel gave a mean absorbance of
0.174, 0.150, and 0.201 with relative standard deviation ±1.5, ±1.3, and ±1.8%, respectively. The high efficiency of cloud
point extraction to carry out the determination of analytes in complex matrices was demonstrated. The proposed method has
been applied for determination of trace amount of palladium, gold and nickel in certified reference material and water samples
with satisfactory results. 相似文献
4.
L. Sajo-Bohus M. C. Scott E. D. Greaves L. J. Somervaille S. Green T. Avila F. Loaiza L. Foglietta 《Journal of Radioanalytical and Nuclear Chemistry》2004,259(2):251-255
Gamma-ray induced X-ray emission (GIXE) technique for elemental lead in-vivo tibial measurement using a large volume hyper
pure germanium detector is presented with the most convenient source-sample-detector geometry. The system operates advantageously
when several parameters are considered for a lower dead time operation. The detection limit (DL) is better that 3.5 μg/g of
Ca. Results of in-vivo average tibial lead concentration for some of the monitored groups are: control 7 μg of lead per g
of Ca; gasoline filling attendants 6 μg/g of Ca; custom office workers near the DL; industrial workers range from DL up to
84±3 μg/g of Ca, suggesting that lead accumulation in the bone does not represent a major health risk
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
5.
A flow-injection UV spectrophotometric method was developed for the determination of ambroxol hydrochloride in tablets. The
quantitative determination of ambroxol was performed at 245 nm using distilled water as the carrier solvent. In this study,
the flow rate, loop volume, and the number of injections per hour were 15 mL/min, 193 μL, and 100, respectively. The analytical
signal of ambroxol was linear in the concentration range of 40–200 μg/mL. The detection limit and limit of quantification
were found as 11.55 and 38.49 μg/mL, respectively. The results for the determination of ambroxol in tablets, 29.99 ± 0.23
mg (mean ± SD), were in good agreement with the labeled quantities (30 mg/tablet). A relatively high recovery value (100.4%)
shows the accuracy of the proposed method. Furthermore, the results obtained were in accordance with those obtained by the
HPLC method, which were used as a comparison method for the determination of ambroxol HCl, as far as the Student’s t-test
and Fisher test results were concerned. It was concluded that the proposed flow-injection UV spectrophotometric method was
fast, accurate, precise, and suitable for automation in the determination of ambroxol.
The text was submitted by the authors in English. 相似文献
6.
A method based on solid phase extraction was developed for the determination of the herbicide triallate and its metabolite
2,3,3-trichloro-prop-2-en-sulfonic acid (TCPSA). Soil samples were extracted with methanol and diluted with water to yield
a methanol/water ratio of 1 : 4. Triallate was adsorbed on C18 cartridges while TCPSA was enriched on quaternary amine anion exchange resins. Cartridges were eluted with methanol/ethyl
acetate and methanol/sulfuric acid mixture, respectively. TCPSA methyl ester was formed using trimethyl orthoformate and subsequently
analyzed by GC/ECD. Determination limits of both target compounds were 5 μg/kg soil with recoveries of 100 ± 12% for triallate
and 57 ± 5% for TCPSA. In water analysis, determination limits were 0.05 μg/L with recoveries of 84 ± 14% for triallate and
100 ± 22% for TCPSA. In laboratory batch experiments, concentration of triallate decreased from 2690 to 1550 μg/kg soil within
59 days. 14 days after triallate application, TCPSA was determined to be 14 μg/kg which increased to 98 μg/kg soil at the
end of the incubation period. Soil/water distribution coefficients in loamy sand soil were 102 for triallate and 0.02 for
TCPSA which indicated a higher leaching tendency of the polar metabolite.
Received: 2 July 1997 / Revised: 15 September 1997 / Accepted: 25 September 1997 相似文献
7.
G. A. Shabir 《Journal of Analytical Chemistry》2011,66(10):963-968
A new and simple isocratic high-performance liquid chromatographic method with ultraviolet detection is described for simultaneous
determination of active guaiphenesin and preservative sodium benzoate in Liqufruta garlic cough medicine formulation. The
chromatographic separation was achieved using a Zorbax CN; 150 mm × 4.6 mm and 5 μm particle size column employing acetonitrile
and water (20: 80, v/v) containing 0.1% formic acid (pH 3.5 ± 0.05) as the mobile phase. The method was validated with respect
to linearity, range, precision, accuracy, specificity, limit of detection and limit of quantitation. The both analytes were
detected by UV-Vis detector at 245 nm. The method was linear over the concentration range of 0.2–0.8 mg/mL and 0.02–0.06 mg/mL
for guaiphenesin and sodium benzoate, respectively. The limit of detection was found to be 0.14 μg/mL for GP and 0.06 μg/mL
for SB and the quantification limit was 0.54 μg/mL for GP and 0.22 for SB. Accuracy, evaluated as recovery, was in the range
of 97.8–100.0%. Intra-day precision and intermediate precision showed relative standard deviation <1% in each case. 相似文献
8.
J. Feldmann Katie John Paramee Pengprecha 《Analytical and bioanalytical chemistry》2000,368(1):116-121
Cation exchange and anion exchange liquid chromatography were coupled to an ICP-MS and optimised for the separation of 13
different arsenic species in body fluids (arsenite, arsenate, dimethylarsinic acid (DMAA), monomethylarsonic acid (MMAA),
trimethylarsine oxide (TMAO), tetramethylarsonium ion (TMA), arsenobetaine (AsB), arsenocholine (AsC), dimethylarsinoyl ethanol
(DMAE) and four common dimethylarsinoylribosides (arsenosugars). The arsenic species were determined in seaweed extracts and
in the urine and blood serum of seaweed-eating sheep from Northern Scotland. The sheep eat 2–4 kg of seaweed daily which is
washed ashore on the most northern Island of Orkney. The urine, blood and wool of 20 North Ronaldsay sheep and kidney, liver
and muscle from 11 sheep were sampled and analysed for their arsenic species. In addition five Dorset Finn sheep, which lived
entirely on grass, were used as a control group. The sheep have a body burden of approximately 45–90 mg arsenic daily. Since
the metabolism of arsenic species varies with the arsenite and arsenate being the most toxic, and organoarsenic compounds
such as arsenobetaine the least toxic compounds, the determination of the arsenic species in the diet and their body fluids
are important. The major arsenic species in their diet are arsenoribosides. The major metabolite excreted into urine and blood
is DMAA (95 ± 4.1%) with minor amounts of MMAA, riboside X, TMA and an unidentified species. The occurrence of MMAA is assumed
to be a precursor of the exposure to inorganic arsenic, since demethylation of dimethylated or trimethylated organoarsenic
compounds is not known (max. MMAA concentration 259 μg/L). The concentrations in the urine (3179 ± 2667 μg/L) and blood (44
± 19 μg/kg) are at least two orders of magnitude higher than the level of arsenic in the urine of the control sheep or literature
levels of blood for the unexposed sheep. The tissue samples (liver: 292 ± 99 μg/kg, kidney: 565 ± 193 μg/kg, muscle: 680 ±
224 μg/kg) and wool samples (10 470 ± 5690 μg/kg) show elevated levels which are also 100 times higher than the levels for
the unexposed sheep.
Received: 29 February 2000 / Revised: 26 April 2000 / Accepted: 1 May 2000 相似文献
9.
Hüseyin Ba Mustafa Lale A. Rehber Türker 《Fresenius' Journal of Analytical Chemistry》1999,363(3):224-230
By using the adsorbent Saccharomyces cerevisiae immobilized on sepiolite an adsorption-elution method was developed for the preconcentration of Cu, Zn, and Cd followed by
flame atomic absorption spectrometry (FAAS). Recoveries were 98.3 ± 0.4% for Cu, 94.2 ± 0.3% for Zn, and 99.04 ± 0.04% for
Cd at 95% confidence level obtained by the column method. The influence of sea water matrix elements on the separation of
the trace elements was also assessed by using the column procedure. The breakthrough capacities were found to be 74 μmol/g
for copper, 128 μmol/g for zinc and 97 μmol/g for cadmium. After optimization the proposed method was applied to the trace
metal determination in sea and river water.
Received: 8 June 1998 / Revised: 8 September 1998 / Accepted: 16 September 1998 相似文献
10.
Norbert Szoboszlai Erzsébet Andrási Zsolt Ajtony Ivett Császma 《Mikrochimica acta》2001,137(1-2):81-86
A method is reported for measuring Se and Sn in human brain tissue. The patients from whom the samples were taken had no
diseases in their central nervous system. Microwave energy was applied to digest the brain samples. The digested samples were
analyzed without dilution by transversely heated graphite atomizer for atomic absorption spectrometry with longitudinal Zeeman
background correction. The dependence of integrated absorbance on various chemical modifiers has been examined. The most appropriate
technique proved to be 5 μl sample injection using 20 μg prereduced palladium-nitrate for Se determination, and 20 μl sample
injection applying 10 μg palladium-nitrate + 3 μg magnesium-nitrate for the measurements of Sn. The optimal temperature program
was found to be 1200 °C pyrolysis and 2100 °C atomisation temperature for Se and 1500 °C pyrolysis and 2300 °C atomisation
temperature for Sn. Accuracy of the applied techniques was tested by the analysis of standard reference materials. The precision
was ±5% for Se and ±10% for Sn. The range of recovery values was 85–95% for Se and 95–105% for Sn. The mean Se concentrations
in the investigated brain parts ranged from 200 to 700 ng/g, while the Sn concentrations were between 20 and 300 ng/g dry
weight.
Received October 3, 2000. Revision February 1, 2001. 相似文献
11.
R. P. Choudhury R. Acharya A. G. C. Nair A. V. R. Reddy A. N. Garg 《Journal of Radioanalytical and Nuclear Chemistry》2008,276(1):85-93
Four plant parts (leaves, roots, fruits and seeds) of twenty samples of sixteen antidiabetic herbs including three commercially
marketed capsules have been analyzed for 6 minor (Na, K, Ca, Cl, Mg, and P) and 21 trace (As, Ba, Br, Ce, Co, Cr, Cs, Cu,
Eu, Fe, Hg, La, Mn, Rb, Sb, Sc, Se, Sm, Th, V and Zn) elements by instrumental neutron activation analysis (INAA). Further,
Ni, Cd and Pb contents were determined by AAS. Elemental data were validated by simultaneously analyzing reference material
(RM), MPH-2 Mixed Polish Herbs. Several elements such as Cr and V (1–2 μg/g), Rb (10–40 μg/g), Cs (80–300 ng/g), Se (∼100
ng/g) and Zn (25–60 μg/g) play an important role in diabetes mellitus. Interelemental linear correlations have been observed
for Cu vs. Zn (r = 0.89) and Rb vs. Cs (r = 0.87). K/P ratio varies in a narrow range with a mean value of 6.2 ± 1.4. Toxic elements As and Hg were found in <1 μg/g
whereas Cd and Pb were in ∼5 μg/g and <10 μg/g, respectively. 相似文献
12.
Juan Agüero José-Esteban Peris Eduardo San-Martín 《Fresenius' Journal of Analytical Chemistry》1999,363(3):289-293
An analytical method for detecting and quantifying cefotaxime in plasma and several tissues is described. The method was
developed and validated using plasma and tissues of rats. The samples were analyzed by reversed phase liquid chromatography
(HPLC) with UV detection (254 nm). Calibration graphs showed a linear correlation (r > 0.999) over the concentration ranges
of 0.5–200 μg/mL and 1.25–25 μg/g for plasma and tissues, respectively. The recovery of cefotaxime from plasma standards prepared
at the concentrations of 25 μg/mL and 100 μg/mL was 98.5 ± 3.5% and 101.8 ± 2.2%, respectively. The recovery of cefotaxime
from tissue standards of liver, fat and muscle, prepared at the concentration of 10 μg/g was: 89.8 ± 1.2% (liver), 103.9 ±
6.5% (fat) and 97.8 ± 2.1% (muscle). The detection (LOD) and quantitation (LOQ) limits for plasma samples were established
at 0.11 μg/mL and 0.49 μg/mL, respectively. The values of these limits for tissues samples were approximately 2.5 times higher:
0.3 μg/g (LOD) and 1.25 μg/g (LOQ). For plasma samples, the deviation of the observed concentration from the nominal concentration
was less than 5% and the coefficient of variation for within-day and between-day assays was less than 6% and 12%, respectively.
The method was used in a pharmacokinetic study of cefotaxime in the rat and the mean values of the pharmacokinetic parameters
are given.
Received: 25 May 1998 / Revised: 27 July 1998 / Accepted: 1 August 1998 相似文献
13.
D. Q. Thuyet K. Yamazaki T. K. Phong H. Watanabe D. T. T. Nhung K. Takagi 《Journal of Analytical Chemistry》2010,65(8):843-847
A method for the determination of imidacloprid in paddy water and soil was developed using liquid chromatography electrospray
ionization-tandem mass spectrometry (LC/ESI-MS/MS). Separation of imidacloprid was carried out on a Shimadzu C18 column (150 mm × 4.6 mm, 4.6 μm) with an acetonitrile-water
(50: 50, v/v) mobile phase containing 0.1% of acetic acid. The flow rate was 0.3 mL/min in isocratic mode. The product ion
at 209 m/z was selected for quantification in multiple-reaction monitoring scan mode. Imidacloprid residues in soil were extracted by
a solid-liquid extraction method with acetonitrile. Water samples were filtered and directly injected for analysis without
extraction. Detection limits of 0.5 μg/kg and 0.3 μg/L were achieved for soil and water samples, respectively. The method
had recoveries of 90 ± 2% (n = 4) for soil samples and 100 ± 2% (n = 4) for water samples. A linear relationship was observed throughout the investigated range of concentrations (1–200 μg/L),
with the correlation coefficients ranging from 0.999 to 1.000. 相似文献
14.
A sensitive and selective HPLC–UV method established for determination of picroside I in dog plasma has been used to study
the pharmacokinetics of the drug after intravenous administration of three different doses. Sample pretreatment consists in
deproteination by addition of acetonitrile; l-ascorbic acid was used to improve the stability of picroside I. The lower limit of quantification of picroside I was 0.05 μg mL−1. The recovery of the method was up to 90%. After intravenous administration to dogs picroside I was mainly distributed in
the central compartment and was rapidly eliminated from the plasma; the mean elimination half-life was 30.54 ± 4.34, 30.20 ± 3.78,
and 34.02 ± 1.88 min for doses of 2.5, 5, and 15 mg kg−1, respectively, and the respective values of AUC
0–∞ were 81.04 ± 19.95, 198.50 ± 27.77, and 586.44 ± 103.08 μg min mL−1. The different doses had no significant effect on the main pharmacokinetic data and the kinetics seemed to be linear in dosage
range 2.5–15 mg kg−1. 相似文献
15.
A simple, selective, rapid, and economical reversed phase high performance liquid chromatography(RP-HPLC) method for the determination of doxofylline in the commercial dosage form has been developed and validated. The separation
and quantification were achieved on an HiQ Sil C 18 W column using a mobile phase of acetonitrile: buffer (50: 50), pH 3,
at a flow rate of 1 mL/min with detection of analyte at 272 nm. The separation was achieved within 3.1 ± 0.3 min for doxofylline
sample. The method showed good linearity in the range of 10–80 μg/mL. The intra and inter day RSD ranged from 0.37–0.53%.
The recovery (mean ± S.D.) of low, middle and high concentrations were 100.04 ± 0.80, 100.01 ± 0.20, 100.07 ± 0.30 respectively.
Limit of detection and limit of quantification were 0.03 and 0.1 μg/mL, respectively. 相似文献
16.
An X-ray fluorescence spectrometric multivariable regression procedure is described for the determination of titanium and
molybdenum in special steels and alloys in the concentration range from 9.41% down to 120 μg/g using Ti Kα1,2 and Mo Kα1,2 analyte lines. In general, better results have been achieved in first order base curve polynomials using LiF (200) crystal
in combination with scintillation counter (SC) or krypton proportional counter (KPC). However, LiF (220)+SC combination also
yields favorable results for Mo. The measured concentrations of Ti and Mo for BAS alloy steel standards agree very well with
their certified values. The automated XRFS method for the determination of Ti and Mo appears to be free from matrix effects
and is suitable for their measurement in special steels and alloys down to 120 μg/g concentration of Ti with a precision of
3.2% and an accuracy of ±2.5% and for Mo down to 350 μg/g with a precision of <1% and an accuracy of ±1.1%. The sensitivities
for these lowest concentrations are calculated to be 5960 counts/mass %/s and 8000 counts/mass %/s for Ti and Mo, respectively. 相似文献
17.
Lei Zhang Ting Huang Xueyan Liu Min Zhang Kai Li 《Journal of Analytical Chemistry》2011,66(4):368-372
A novel sorbent, nano-Al2O3 was employed for the separation and preconcentration of thallium from aqueous solution in batch equilibrium experiments.
It was found that the adsorption percentage of thallium ions was close to 100% at pH 4.5, and the desorption by 1.0 mL of
0.25 M HCl reached 99%. The adsorption equilibrium was well described by the Langmuir isotherm model with maximum adsorption
capacity of 5.78 mg/g (20 ± 0.1°C). The enrichment factor values of Tl(III) was 25 for 25 mL sample. Detection limit of thallium
(3σ, n = 11) equal to 0.8 μg/mL and relative standard deviation (2.4%) were obtained. The method has been successfully applied to
the determination of trace thallium in some environmental samples and the certified reference material polymetallic nodule
(GBW07296) with satisfactory results. 相似文献
18.
A successful flow-through system was developed for trace analysis of copper using DPASV with a glassy-carbon electrode. Periodical
chemical regeneration of the electrode with a 1 mol/L NaOH solution increased sensitivity and precision. The method was shown
to be applicable with a detection limit of 0.56 μg/L, with a determination time of less than 7 min per measurement (without
deaeration time). The drawback of the system is the 10 min deaeration time. The system gave an accuracy of 0.090±0.005% for
a certified reference material of low alloy steel containing 0.090±0.004% Cu. Applicability to various fresh water samples
with a Cu content between 1.57 and 13.11 μg/L with an RSD<2.36% is illustrated.
Received: 11 March 1996/Revised: 1 July 1996/Accepted: 4 July 1996 相似文献
19.
A successful flow-through system was developed for trace analysis of copper using DPASV with a glassy-carbon electrode. Periodical
chemical regeneration of the electrode with a 1 mol/L NaOH solution increased sensitivity and precision. The method was shown
to be applicable with a detection limit of 0.56 μg/L, with a determination time of less than 7 min per measurement (without
deaeration time). The drawback of the system is the 10 min deaeration time. The system gave an accuracy of 0.090±0.005% for
a certified reference material of low alloy steel containing 0.090±0.004% Cu. Applicability to various fresh water samples
with a Cu content between 1.57 and 13.11 μg/L with an RSD<2.36% is illustrated.
Received: 11 March 1996/Revised: 1 July 1996/Accepted: 4 July 1996 相似文献
20.
U. Risse Elke Flammenkamp A. Kettrup Stefaan Vandendriessche 《Fresenius' Journal of Analytical Chemistry》1999,363(1):33-37
A Certified Reference Material (CRM) for determination of aromatic hydrocarbons in air was developed. The CRM 562 consists
of aromatic hydrocarbons sorbed on charcoal in glass tubes. Initial feasibility studies established that a homogeneous and
stable batch could be prepared. Three intercomparisons prior to the certification allowed the identification of various sources
of error. Then, a batch of about 3000 tubes was charged and certified on the basis of analyses carried out in 15 European
laboratories. The preparation of the reference material and the results of the certification exercise is described. An overview
on the analytical techniques used and the quality control guidelines are also presented. The certified values are 15.0 ± 0.4
μg benzene, 147.3 ± 3.8 μg toluene, 96.4 ± 2.5 μg m-xylene and 93.0 ± 2.9 μg o-xylene per tube. This reference material is
recommended for quality control of measurements in the field of occupational hygiene.
Received: 12 May 1998 / Revised: 28 August 1998 / Accepted: 1 September 1998 相似文献