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1.
Determination of boron in water samples by chemical prompt gamma neutron activation analysis 总被引:1,自引:0,他引:1
P. S. Ramanjaneyulu Y. S. Sayi T. Newton Nathaniel A. V. R. Reddy K. L. Ramakumar 《Journal of Radioanalytical and Nuclear Chemistry》2007,273(2):411-414
Boron concentration has been determined in groundwater samples, collected from Khuchch, Gujarat, India, by prompt gamma neutron
activation analysis (PGNAA) after selective separation and pre-concentration by solvent extraction with 10% 2-ethyl hexane
1,3-diol in CHCl3. Solvent extraction separation helped to eliminate the interfering elements in PGNAA determination of boron. The sensitivity
of PGNAA is found to be 18.83 cps/mg B based on the slope of a calibration plot obtained by carrying out measurements on synthetic
boric acid samples containing boron in the range of 30–150 μg. Detection limit of the method is 0.2 μg/g counted for 35,000
seconds at a sample size of 15 gram. The precision (relative standard deviation at 1σ level) and accuracy of the method is
5%. The analytical results of the present method agreed well with well-established spectrophotometric determination of boron
as boron-curcumin complex and inductively coupled plasma atomic emission spectroscopy (ICP-AES). 相似文献
2.
Summary The supercritical-fluid extraction of vitamins D2 and D3 with carbon dioxide is reported for the first time. The extraction recovery was enhanced by direct addition of diethyl ether
to sample contained in the extraction cell. Separation and detection of the analytes was performed off-line by reversed-phase
liquid chromatography with UV-detection. The quantification limit of the method is 4.1 μg for both analytes, with precision,
expressed as relative standard deviation, of 3.8 and 6.3% for vitamins D2 and D3, respectively (η=7). The proposed method has been applied to the determination of vitamin D in different pharmaceutical products;
recoveries were between 85 and 105%. 相似文献
3.
D. S. Tsar’kov E. S. Ryndina M. A. Proskurnin V. M. Shkinev 《Journal of Analytical Chemistry》2011,66(2):166-170
A novel method is proposed for the extraction-thermal lens quantification of cobalt with Nitroso-R-Salt based on the distribution
of the colored complex in a two-phase aqueous system on the basis of poly-ethylene glycol (PEG) and an ammonium sulfate solution followed by its thermal lens detection in the extract. The limit of detection is 0.3 μM
(20 ng/mL); the lower limit of the analytical range is 0.7 μM (40 ng/mL); the relative standard deviation for the concentrations
1–50 μM makes 1–3% (n = 6, P = 0.95). In the determination of cobalt by spectrophotometry under the same conditions, the detection limit is 10 μM (0.6
μg/mL) and the lower limit of the analytical range is 40 μM (2.5 μg/mL). The precision of thermal lens measurements in PEG
solutions is higher in comparison to that in aqueous ones because of the weaker interference of convection in aqueous solutions
of PEG. 相似文献
4.
I. V. Gruzdev M. V. Alferova B. M. Kondratenok I. G. Zenkevich 《Journal of Analytical Chemistry》2011,66(10):955-962
A procedure is developed for determination of trace amounts of simple aniline, 2- and 4-chloro-anilines, 2,4- and 2,6-dichloroanilines,
2,4,5- and 2,4,6-trichloroanilines in drinking water; it includes the formation of bromo derivatives, solvent extraction with
toluene, and gas chromatography monitoring with electron-capture detection. The conditions of bromination for chloroanilines
in aqueous solutions are refined; the bromination agent in use is bromine water in the presence of glycine. The analytical
range makes 0.01–10 μg/L; relative standard deviation, 0.01–0.08; detection limits, 0.002–0.007 μg/L; and the duration of
analysis, 50 min. 相似文献
5.
Sandra Babić Dragana Mutavdžić Pavlović Danijela Ašperger Martina Periša Mirta Zrnčić Alka J. M. Horvat Marija Kaštelan-Macan 《Analytical and bioanalytical chemistry》2010,398(3):1185-1194
An analytical method for multi-class pharmaceuticals determination in wastewater has been developed and validated. Target
compounds were: sulfonamides (sulfadiazine, sulfaguanidine, sulfamethazine, sulfamethoxazole), fluoroquinolones (ciprofloxacin,
enrofloxacin, norfloxacin), diaminopyrimidine (trimethoprim), anaesthetic (procaine), anthelmintic (praziquantel and febantel),
and macrolide (roxithromycin). The method involves pre-concentration and clean-up by solid-phase extraction (SPE) using Strata-X
extraction cartridges at pH 4.0. Target analytes were identified and quantitatively determined by liquid chromatography–tandem
mass spectrometry using multiple reaction monitoring (MRM). Recoveries were higher than 50% with relative standard deviation
(RSD) below 18.3% for three concentrations. Only for sulfaguanidine was low recovery obtained. Matrix effect was evaluated
using matrix-matched standards. The method detection limit (MDL) was between 0.5 and 5 ng L−1 in spiked water samples. The precision of the method, calculated as relative standard deviation, ranged from 0.5 to 2.0%
and from 1.4 to 8.3 for intra-day and inter-day analysis, respectively. The described analytical method was used for determination
of pharmaceuticals in effluent wastewaters from the pharmaceutical industry. 相似文献
6.
L. F. Capitán-Vallvey Mahmoud K. A. Deheidel R. Avidad 《Fresenius' Journal of Analytical Chemistry》1998,362(3):307-312
A phosphorimetric solid phase assay is proposed for the determination of the pesticide carbaryl (CBL) at room temperature.
CBL was spotted on filter paper together with Tl(I) as heavy metal, and dried for 3 min, after which the diffuse transmitted
phosphorescence was measured using two quartz plates to avoid the quenching effect produced by atmospheric oxygen. The linear
dynamic range was 0.5–4.0 μg/mL and the detection and quantification limits were 0.09 and 0.31 μg/mL, respectively. The precision
of the method, expressed as relative standard deviation, was 2.3% for a sample containing 2.0 μg/mL of CBL. The method was
applied to the determination of CBL residues in cereals, potatoes and waters, obtaining recoveries ranging between 92 and
105%.
Received: 10 October 1997 / Revised: 2 February 1998 / Accepted: 7 February 1998 相似文献
7.
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
8.
A cloud point extraction-preconcentration by the formation of ternary complex was applied to the determination of trace Cr(VI)
in water samples. The method is based on the formation of a purplish red complex of Cr(VI) with phenylfluorone in the presence
of cetyltrimethylammonium bromide in acetate buffer media and mixed micelle-mediated extraction of the complex. The use of
cloud point extraction (CPE) coupled with spectrophotometric detection allows the determination of chromium at μg levels. The chemical variables affecting
the analytical performance of the combined methodology were studied and optimised. The proposed method allowed the determination
of chromium(VI) in the range 5–100 μg/L with good precision and accuracy and the detection limit was found to be 1.04 μg/L.
The interference of concomitant ions on the CPE of Cr(VI) was investigated. Recoveries in the range of 97–102% were obtained
by analysis of spiked real samples. The method was successfully applied to the determination of chromium in various water
samples.
The article is published in the original. 相似文献
9.
T. A. Filimonova V. V. Senyuta M. A. Proskurnin A. V. Fokin O. B. Ovchinnikov S. V. Egerev 《Moscow University Chemistry Bulletin》2011,66(3):175-178
Using a model system, the applicability of the frontal configuration of optoacoustic spectroscopy in analytical practice is
shown. An optoacoustic cell made using layered-prism geometry was designed and tested; it ensures operation with a layer thickness
of 20–100 μm and sample volumes of 50–100 μl. Conditions are proposed for determining iron(II) in the form of tris(1,10-phenanthrolinate)
with the detection limit of 3 × 10−7 M, which is less that the detection limit under similar induction conditions and for the same determination procedure using
thermal-lens spectrometry (4 × 10−7 M). The determination has high reproducibility (relative standard deviation for 10−6 M is 0.005) and expressivity (1 min per sample detection). 相似文献
10.
Determination of cadmium in water samples by graphite furnace atomic absorption spectrometry after cloud point extraction 总被引:3,自引:0,他引:3
The formation of a complex with 2-(5-brom-2-pyridylazo)-5-(diethylamino)-phenol (5-Br-PADAP) and cloud point extraction have
been applied to the preconcentration of cadmium followed by its determination by graphite furnace atomic absorption spectrometry
(GFAAS) using octylphenoxypolyethoxyethanol (TritonX-114) as surfactant. The chemical variables affecting the separation were
optimized. At pH 7.0, preconcentration of only 10 mL of sample in the presence of 0.05% TritonX-114 and 2.5 × 10−6 M 5-Br-PADAP enabled the detection of 0.04 μg/L cadmium. The enrichment factor was 21 for cadmium. The regression equation
was A = 0.0439C(μg/L) + 7.2 × 10−3. The correlation coefficient was 0.9995. The precision for 10 replicate determinations at 10 μg/L Cd was 2.7% relative standard
deviation (RSD). The proposed method has been applied to the determination of cadmium in water samples.
The text was submitted by the authors in English. 相似文献
11.
An analytical method for the determination of UV filter substances in fish tissue has been developed and validated using benzophenone-3,
3-(4-methylbenzylidene)-camphor, 2-ethylhexyl-2-cyano-3,3-diphenyl-2-propenoate and 2-ethylhexyl 3-(methoxyphenyl)-2-propenoate
as target analytes. The fish fillets were homogenised and extracted by Soxhlet extraction. The extracts were run through a
clean-up process including gel permeation chromatography followed by solid-phase extraction. Quantification of the compounds
was performed using liquid chromatography with tandem mass spectrometric detection. Blank fish as well as spiked blank fish
were analysed to validate the analytical method. The analytical method developed has the multiple advantages of enabling separation,
simultaneous identification and quantification of each of the four selected compounds in a single run. Contamination of blank
samples and abnormally high concentrations in spiked samples were avoided by taking extensive precautions during the fish
preparation procedure. The method was validated in accordance with internationally accepted criteria, such as specificity,
accuracy and repeatability. The combination of LC with tandem mass spectrometry ensures a high level of specificity. The accuracy
of the method was reported as the mean recovery rate for the analytes in the sample matrix. Mean recoveries were in the range
86–108%. The precision is expressed as the relative standard deviation, and in all but one of the cases was 20% or below.
The accuracy of the method allows residue analyses to be performed on biological matrices at ng/g levels. The determined limit
of quantification for each analyte was 8 ng/g fish. For all spiking levels ≥8 ng/g, relative standard deviations were ≤ 20%. 相似文献
12.
LC Determination of Anethole in Aniseed Drinks 总被引:1,自引:0,他引:1
A method for the determination of anethole in aniseed drinks by high performance liquid chromatography (HPLC) is proposed. A C-18 column and a methanol-water (80:20, v/v) mobile phase with isocratic elution were used. UV detection at 257 nm was carried out. Validation was performed according to the EURACHEM guidelines, considering precision, trueness, robustness, linearity and sensitivity. The detection and quantification limits were 2.3 and 7.7 μg L−1, respectively. Recoveries of 95–101% were obtained. Repeatability, calculated as relative standard deviation was 0.9%. Reproducibility under intermediate precision conditions, expressed as relative standard deviation, was 1.6%. The method was compared with the gas chromatographic one, proposed by the European regulations. 相似文献
13.
In this study, the determination of 4-Bromoaniline (4-BA) in green algae Chlamydomonas reinhardtii (C. reinhardtii) was investigated by applying continuous-flow microextraction (CFME) combined with high-performance liquid chromatography
(HPLC). Continuous-flow microextraction was conducted in a homemade glass chamber, i.e. the sample solution flowed through
a constant volume drop of solvent in the chamber at a constant flow rate. The effects of different factors on extraction efficiencies
were also investigated and these factors included the kind of extraction solvent, solvent drop volume, sample flow rate, extraction
time and addition amount of salt. Under the optimum extraction conditions (extraction solvent, carbon tetrachloride; solvent
drop volume, 3.5 μL; sample flow rate, 1.0 mL min−1; extraction time, 10 min; no addition of salt), the calibration plot was set up by plotting peak area against a series of
4-Bromoaniline concentrations (0.01–10 μg mL−1) in aqueous solution. The correlation coefficient (r) was 0.9990. The limit of detection (LOD) was 0.6 ng mL−1. The precision of this method was obtained by successive five time analyses of 100-ng mL−1 standard solution of 4-Bromoaniline, and the relative standard deviation (RSD) was 3.5%. The concentration factor was calculated
by the ratio of peak area of the analyte obtained after and before extraction and found to be 10.6. 4-Bromoaniline residues
in Chlamydomonas. reinhardtii cells and tap water samples were satisfactorily analyzed according to the method described above. 相似文献
14.
Magdalena Michulec Piotr Konieczka Jacek Namieśnik 《Accreditation and quality assurance》2007,12(5):257-262
This paper describes the validation of a HS-GC-FID method (based on the Pharmacopeia’s method) for the determination of ethanol
content in tablets. A general view of the procedure development/optimization process is presented. The main point of this
study is the calculation of validation parameters. Selectivity of the method was determined. Linearity (r > 0.997) was observed in the range from 9.0 to 3,040 μg of ethanol per sample (because the mass of the tablets used was around
200 mg, this corresponds to 45–15,200 μg g−1). The method showed good recoveries (average 99.0%), and a relative standard deviation for repeatability and intermediate
precision of 4.5% and 5.5% respectively. The limit of detection was calculated to be 3.0 μg of ethanol per sample (15 μg g−1). The uncertainty budget was done according to the "Guide to the Expression of Uncertainty in Measurement" (GUM)[1], and a relative expanded uncertainty was estimated as 4.8%. 相似文献
15.
A radiometric method based on substoichiometric isotope dilution analysis has been developed for the determination of mercury
using cetyltrimethylammonium bromide (CTAB) as the substoichiometric reagent. The method is based on the extraction of mercury
as an ionassociation complex of tetraiodomercurate(II) ion with a substoichiometric amount of CTAB in benzene. The calibration
graph was found to be linear in the range 0–10 μg Hg (II) in the aqueous phase of 10 ml volume. A detection limit of 0.06
μg·ml−1 could be achieved by the proposed method. The relative standard deviation of the method was found to be 3.0% and the method
has been successfully applied to study the determination of mercury in various synthetic mixtures. 相似文献
16.
Wang Y Zhang W Dong Y Fan R Sheng G Fu J 《Analytical and bioanalytical chemistry》2005,383(5):804-809
A high-performance liquid chromatographic method with fluorescence detection has been developed to determine the urinary polycyclic
aromatic hydrocarbon metabolites 2-hydroxynaphthalene, 2-hydroxyfluorene, 9-hydroxyphenanthrene, 1-hydroxypyrene and 3-hydroxybenz[a]pyrene.
Solid phase extraction (SPE) was used to clean up the samples, and washing with 30% methanol was found to be the best way
to remove interferences in the matrix. The method detection limits ranged from 0.044 μg/L for 1-hydroxypyrene to 1.615 μg/L
for 3-hydroxybenz[a]pyrene, and the recoveries ranged between 40% for 3-hydroxybenz[a]pyrene and 99% for 2-hydroxynaphthalene.
The within-day relative standard deviation was lowest for 2-hydroxynaphthalene at 0.67% and went up to 2.42% for 3-hydroxybenz[a]pyrene,
and the between-day relative standard deviation ranged from 3.84% for 9-hydroxyphenanthrene to 10.42% for 2-hydroxyfluorene.
The correlation coefficients were between 0.9962 and 0.9998. The developed method was successfully used to analyze samples
from student volunteers in a high school. 相似文献
17.
A rapid and inexpensive method for simultaneous quantification of terbumeton (TER), and its major potential metabolites (TED;
terbumeton-desethyl, TOH; terbumeton-2-hydroxy and TID; terbumeton-deisopropyl) in soil bulk water (SBW) samples is proposed.
The analytical method involves extraction–concentration from SBW samples using a graphitized carbon black (GCB) cartridge
followed by their separation–detection by reversed-phase high-performance liquid chromatography analysis using a C18 column and a diode array detector. A mobile phase of acetonitrile−0.005 mol L−1 phosphate buffer (pH 7.0) (35:65, v/v) at a flow rate of 0.8 mL min−1 in isocratic elution mode has been used. After optimization of the extraction and separation conditions, this method can be
used for the simultaneous determination of investigated compounds in the range of the international limits of 0.1 μg L−1. For TER the detection limit was 0.009 μg L−1 and it was 0.100, 0.550, and 0.480 μg L−1 for TED, TOH, and TID, respectively. The recoveries of TER, TED, TOH, and TID from SBW samples, measured at three levels of
concentration range, were found to be between 48.0 and 102.0%. The intra-day precision measured by relative standard deviation
(RSD) was always lower than 9.0%. 相似文献
18.
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
19.
A novel method combining matrix solid phase dispersion (MSPD) with Soxhlet simultaneous extraction clean-up (SSEC) was developed.
Being a single-step extraction and clean-up procedure, it could be used instead of multistep solvent extraction and Florisol
column clean-up. It not only reduces sample contamination during the procedure, but it also decreases the amount of organic
solvent needed. The retention times of standards were used to qualitatively assess the method, and the external standard method
was used to quantitatively assess it. Residues of organochlorine pesticides (OCP) in tobaccos were determined by gas chromatography–electron
capture detection (GC–ECD), and their identities were confirmed by the standard addition method (SAM). The performance of
the method was evaluated and validated: the detection limit was 0.01–0.02 μg g−1, relative standard deviations were 5–26%, and recoveries were 72–99% at fortification levels of 0.10, 1.00 and 10.0 μg g−1. The analytical characteristics of MSPD–SSEC compared very favorably with the results from the classical multistep solvent
extraction and Florisol column clean-up method. 相似文献
20.
An optical sensor has been proposed for the determination of silver by spectrophotometry. The sensor was prepared by immobilizing
5(p-dimethylaminobenzylidene)rhodanine on a transparent triacetylcellulose membrane. The effect of different variables on
the response of the sensor was studied and the optimum conditions were established. The sensor responded linearly in the range
1.8–55.6 μM of silver with a limit of detection of 0.8 μM and a response time range of 8–10 min depending on the concentration
of the silver ions. The presented optode is reversible and stable if stored in water for more than one month without reagent
leaching. The relative standard deviation for seven replicated measurement of 4.6 and 37 μM silver was 3.15 and 2.76%, respectively.
The sensor was successfully applied to the determination of silver in a silver sulphadiazine cream, an ore sample, and a radiology
film.
The text was submitted by the authors in English. 相似文献