共查询到20条相似文献,搜索用时 296 毫秒
1.
Puspalata Rajesh G. R. Dey D. B. Naik K. Kishore 《Research on Chemical Intermediates》2008,34(1):53-65
Reactions of 2- and 3-nitro anilines (2- and 3-NA) with eaq−, H-atoms and one-electron reductants have been studied using pulse radiolysis in aqueous solutions. Reactions of eaq− were found to be quite fast with both 2-NA and 3-NA resulting in their corresponding semi-reduced species which are reducing
in nature. Reduction potentials for 2-NA/2-Na•′ have been estimated to be approx. −0.56 Vvs. NHE and that for 3-NA/3-NA•− was found to be between −0.185 V and −0.45 Vvs. NHE. Semi-reduced 2-NA has main absorption peak at 300 nm with a shoulder in the 350 nm region and a broad weak band in
the 470–500 nm region, whereas semi-reduced 3-NA possesses an absorption peak at 520 nm. Reducing radicals such as (CH3)2 C•OH and CO2•− reacted with 2-NA, producing semi-reduced species, whereas reactions of these radicals with 3-NA produced their corresponding
radical-adduct species. 相似文献
2.
Chris Mussell Céline S. J. Wolff Briche Chris Hopley Gavin O’Connor 《Accreditation and quality assurance》2007,12(9):469-474
The method used at LGC for analysis of “total” 19-norandrosterone (19-norandrosterone glucuronide plus “free” 19-norandrosterone)
in urine for the Comité Consultatif pour la Quantité de Matière Pilot Study (CCQM-P68) is described. The analytical method
used was a modified version of the method developed at the National Measurement Institute of Australia, which used a hydrolysis
and derivatisation procedure first described by the German Sports University. This method is routinely used by World Anti-Doping
Agency-accredited laboratories for sports drug testing. The main modifications made to the method were the use of 19-norandrosterone
glucuronide as a calibration standard and 19-norandrosterone glucuronide-d4 as an isotopically labelled internal standard,
and the use of a bench-top quadrupole gas chromatograph–mass spectrometer. The results produced by LGC (2.14 ± 0.15 ng g−1 expanded uncertainty, coverage factor k = 2) were in excellent agreement with those from other participating national metrology institutes and thus further validates
the exact-matching isotope-dilution mass spectrometric procedures used at LGC for a wide range of reference measurement applications,
including measurement of ng g−1 levels of steroids in a biological matrix. 相似文献
3.
Iparraguirre A Prieto A Navarro P Olivares M Fernández LÁ Zuloaga O 《Analytical and bioanalytical chemistry》2011,401(1):339-352
The analysis of organic pollutants in environmental water samples requires a pre-concentration step. Pre-concentration techniques
such as stir bar sorptive extraction (SBSE) have gained popularity since they minimise the use of toxic organic solvents and
can be considered as green analytical techniques. Similar to other pre-concentration techniques, one of the problems when
SBSE is used is the matrix effect, which often occurs during the analysis of environmental water samples such as estuarine
or wastewater samples. The present work studied the matrix effect during SBSE coupled to in-tube derivatisation–thermal desorption
(TD)–gas chromatography–mass spectrometry for the determination of several endocrine disruptor compounds, such as alkylphenols,
bisphenol A, estrogens and sterols, in environmental water samples, after optimisation of the major variables affecting the
determination. Variables such as the addition of methanol or an inert salt to the donor phase, the extraction temperature,
the volume of the donor phase, the stirring rate and the extraction time were studied during the SBSE optimisation. In the
case of the in-tube derivatisation and TD step, the volume of the derivatisation reagent (N,O-bis(trimethylsilyl)triufloroacetamide with 1% of trimethylchlorosilane (BSTFA + 1% TMCS)) and the cryo-focusing temperature
were fixed (2 μL and −50 °C, respectively) according to a consensus between maximum signal and optimal operation conditions.
Good apparent recovery values (78–124%) were obtained for most of the analytes in Milli-Q water, except for 4-tert-octylphenol (4-tOP), which showed apparent recovery values exceeding 100%. Precision (n = 4) was in the 2–27%, and method detection limits were in the low nanogrammes per litre level for most of the analytes studied.
The matrix effect was studied using two different approaches. On the one hand, Milli-Q water samples were spiked with humic
acids, and apparent recovery values were studied with and without correction with the corresponding deuterated analogue. On
the other hand, estuarine water and wastewater samples were spiked with known concentrations of target analytes, and apparent
recoveries were studied as explained above. In general, the matrix effect could be corrected with the use of deuterated analogues,
except for 4-tOP and nonylphenols for which [2H4]-n-nonylphenol did not provide good corrections. 相似文献
4.
Analysis of hormonal steroids in fish plasma and bile by coupling solid-phase extraction to GC/MS 总被引:1,自引:0,他引:1
Budzinski H Devier MH Labadie P Togola A 《Analytical and bioanalytical chemistry》2006,386(5):1429-1439
An analytical procedure for the simultaneous determination of twelve endogenous steroids (testosterone, androstenedione, 17β-estradiol,
estrone, pregnenolone, progesterone, dihydroandrostenedione, dihydrotestosterone, 11α-ketotestosterone, 17α-hydroxyprogesterone,
17α-hydroxypregnenolone, 17α,20β-dihydroxy-4-pregnen-3-one) in plasma and bile samples by solid-phase extraction (SPE) and
gas chromatography/mass spectrometry (GC–MS) has been developed. After enzymatic hydrolysis for bile samples only, samples
were concentrated and purified using two successive SPE (C18 and NH2) cartridges. Analytes were derivatized with a mixture of N-methyl-N-(trimethylsilyl)trifluoroacetamide (MSTFA) / mercaptoethanol / ammonium iodide (NH4I) and determined by GC–MS in selective ion monitoring mode. For most of the steroids monitored, recoveries were in the range
90–120% in plasma and in the range 60–70% in bile, and the reproducibility was below 10% for the complete procedure. Limits
of detection obtained ranged from 0.1 to 0.4 ng/g in fish plasma and from 1.6 to 14 ng/g in fish bile. The developed method
was successfully applied to the determination of plasma steroids in flounders (Platichthys flesus) collected from two French estuaries. 相似文献
5.
Anodic stripping voltammetric determination of total lead, copper and selenium in whole blood and blood serum 总被引:1,自引:0,他引:1
A two-step procedure including appropriate wet-digestions, separation of selenium from interfering ions such as heavy metal
ions with pentyl alcohol and anodic stripping voltammetric (ASV) determination of Pb2+, Cu2+ and SeO3
2– is developed. The elements in digested whole blood and serum sample solutions were determined by using a standard addition
method. 1 × 10–9 mol/L SeO2–
3, Cu2+ and Pb2+ were successfully determined with relative standard deviations of approximately 1–2% (n = 6–8).
Received: 19 August 1996 / Revised: 24 February 1997 / Accepted: 28 February 1997 相似文献
6.
Aman CS Pastor A Cighetti G de la Guardia M 《Analytical and bioanalytical chemistry》2006,386(6):1869-1879
A sensitive, specific and selective multianalyte GC–MS/MS method has been developed for the determination of 11 anabolic hormones
in bovine urine. After adjusting the urine pH to 4.8, the samples were spiked with deuterated internal standards and submitted
to enzymatic hydrolysis with β-glucuronidase/arylsulfatase. Hormones were eluted with methanol through a C18 solid phase cartridge
and submitted to a liquid–liquid extraction. Analytes were derivatized by adding N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) with 1% trimethylchlorosilane and GC–MS data were obtained in the positive
electron impact tandem mass mode. Under these conditions, no matrix effects were observed and limit of detection values were
in the range of 0.005 ng/mL (diethylstilbestrol) to 0.38 ng/mL (17α-methyltestosterone and 17α-ethynylestradiol). Recoveries
from 81% (α-zeranol) to 149% (17α-methyltestosterone) were found under the selected conditions. These results were better
than those found using heptafluorobutyric anhydride (HFBA) as derivative reagent and those measured in full scan and selective
ion monitoring modes. 相似文献
7.
The applicability of ATR-FTIR for the determination of the HDO content in heavy water (D2O) was investigated. Two groups of calibration standard solutions, of low contents (0–1 n% H2O in heavy water) and of higher contents (0–10 n% H2O in heavy water) were prepared by adding properly calculated amount of H2O to D2O by weight. The absorbances at 3400 cm−1 (ν, O–H) against the calibration standards were measured five times using two kinds of interchangeable IREs (1 bound and
9 bound reflections). And four calibration curves were obtained by linear least square fit of the measured absorbances for
the four different measurement conditions, which are (1) for low contents group using 1 bound reflection, (2) for low contents
group using 9 bound reflections, (3) for higher contents group using 1 bound reflection, (4) for higher contents group using
9 bound reflections. Determined contents (c
0) of each calibration standards for the four measurement conditions were obtained by the calibration curves and compared to
the calculated contents (c
cal). The uncertainty sources were considered when the HDO in heavy water is determined according to the procedure of this work.
The uncertainties u(c
0) of the determined contents (c
0) for the four different measurement conditions were calculated. 相似文献
8.
M. A. Campanero B. Calahorra E. García-Quetglás M. Escolar J. Honorato 《Chromatographia》1998,48(7-8):555-560
Summary A sensitive liquid chromatographic assay for the quantitative determination of the opioid analgesic tramadol and its active
metabolite is described. Fluconazole was used as internal standard. The assay involved a singletert-butyl methyl ether extraction and LC analysis with fluorescence detection. Chromatography was at 30°C pumping an isocratic
mobile phase of acetonitrile-water (19∶81, v/v) containing 0.06M NaH2PO4 and 0.05M triethylamine, adjusted to pH 7.90, at 1 mL min−1 through a reversed-phase, 250×4 mm base-stable column. The limit of quantitation of tramadol and its active metabolite was
1 ng mL−1, only 0.5 mL plasma sample was required for the determination. The calibration curve was linear from 1–1000 ng mL−1. Intra and inter-day precision (C.V.) did not exceed 10%. Mean recoveries of 96.38% for tramadol and 96.62% forO-demethyltramadol with CVs of 0.43% and 1.46% were obtained. Applicability of the method was demonstrated by a pharmacokinetic
study on normal volunteers who received 100 mg tramadol intravenously. 相似文献
9.
Marta Concheiro-Guisan Diaa M. Shakleya Marilyn A. Huestis 《Analytical and bioanalytical chemistry》2009,394(2):513-522
A LCMS method was developed and validated for the determination of buprenorphine (BUP), norbuprenorphine (NBUP), buprenorphine
glucuronide (BUP-Gluc), and norbuprenorphine glucuronide (NBUP-Gluc) in placenta. Quantification was achieved by selected
ion monitoring of m/z 468.4 (BUP), 414.3 (NBUP), 644.4 (BUP-Gluc), and 590 (NBUP-Gluc). BUP and NBUP were identified monitoring MS2 fragments m/z 396, 414 and 426 for BUP, and 340, 364 and 382 for NBUP, and glucuronide conjugates monitoring MS3 fragments m/z 396 and 414 for BUP-Gluc, and 340 and 382 for NBUP-Gluc. Linearity was 1–50 ng/g. Intra-day, inter-day and total assay imprecision
(% RSD) were <13.4%, and analytical recoveries were 96.2–113.1%. Extraction efficiencies ranged from 40.7–68%, process efficiencies
38.8–70.5%, and matrix effect 1.3–15.4%. Limits of detection were 0.8 ng/g for all compounds. An authentic placenta from an
opioid-dependent pregnant woman receiving BUP pharmacotherapy was analyzed. BUP was not detected but metabolite concentrations
were NBUP-Gluc 46.6, NBUP 15.7 and BUP-Gluc 3.2 ng/g. 相似文献
10.
An on-line solid phase extraction method, linked to inductively coupled plasma optical emission spectrometry (ICP-OES), has been examined using octadecyl-bonded silica cartridge for determination of low levels of uranium and thorium in aqueous
samples. 2,3-dihydro-9,10-dihydroxy-1,4-anthracenedion forms a hydrophobic complex with cations and the resulted complex was
retained on SPE. The retained complex was eluted using an acidic solution and introduced into ICP for determination. Various
effective parameters and chemical variables such as sample pH, amount of ligand (as a complexing agent), sampling and eluting
flow rates and concentration of the eluent were optimized. Under optimal conditions, calibration curves with dynamic linear
ranges of 1–200 μg/L (r
2 = 0.9999) and 1–500 μg/L (r
2 = 0.9994) for U and Th were obtained, respectively. Detection limits based on three times of standard deviations of blank
by 6 replicates were 0.69 μg/L and 0.84 μg/L for U and Th, respectively. Sample throughput was 10 samples/h. The interference
effects of several metal ions on percentage of recovery of U and Th were also studied. The method was applied to the recovery
and sequential determination of these actinide elements in different water samples. 相似文献
11.
A sensitive analytical method was established for the determination of Th and U in activated concrete samples. The method
combines an anion-exchange separation step with an ICP-MS determination technique. In the ICP-MS measurement, a few μg mL–1 of Al and Ca, a few ng mL–1 of Mn, La, Ce, Nd and Pb and pg mL–1 amounts of Li, Zr, Nb and Ba coexisting in the anion-exchange fraction of Th and U did not interfere. No adverse interference
effects were observed in real sample analyses. The obtained detection limits (3σ, n = 10) of Th and U were 2.3 and 1.8 pg mL–1, respectively. The analytical precisions for ca. 5 μg g–1 Th and ca. 1 μg g–1 U in real activated concrete samples were equally less than 7% RSD. The accuracies obtained by the analysis of GSJ rock standard
samples were –18.1 to 0.4% for the Th determination and –14.0 to –5.7% for the U determination. The method uses the conventional
absolute calibration curve. The internal standard calibration is unnecessary.
Received: 14 March 1999 / Revised: 13 July 1999 / Accepted: 15 July 1999 相似文献
12.
A selective, sensitive, and accurate high-performance liquid chromatographic method for determination of diltiazem in plasma samples has been developed and validated. The effects of mobile phase composition, buffer concentration, mobile phase pH, and concentration of organic modifiers on retention of diltiazem and internal standard were investigated. Solid-phase and liquid–liquid extraction were examined and proposed for isolation of the drug and elimination of endogenous plasma interferences. A 5 m Lichrocart Lichrospher 60 RP-select B chromatographic column was used; the mobile phase was acetonitrile–0.025 mol L–1 KH2PO4 (pH 5.5), 35:65 ( v / v) at a flow-rate of 1.5 mL min–1. The detection wavelength was 215 nm. The calibration plots were linear in the concentration range 20.0–500.0 ng mL–1. The method has been implemented to monitor diltiazem levels in patient samples. 相似文献
13.
Maria Chiara Pietrogrande Dimitri Bacco Mattia Mercuriali 《Analytical and bioanalytical chemistry》2010,396(2):877-885
This paper describes methods for the determination of low-molecular-weight (LMW) dicarboxylic acids in atmospheric aerosols
as important chemical tracers for source apportionment of aerosol organics and for studying atmospheric processes leading
to secondary organic aerosol formation. The two derivatization procedures most widely used in GC analysis of dicarboxylic
acids were compared: esterification using BF3/alcohol reagent and silylation using N,O-bis(trimethylsilyl)-trifluoroacetamide (BSTFA). The advantages and drawbacks of the two methods are investigated and compared
in terms of (1) precision and accuracy of the results and (2) sensitivity and detection limit of the procedure. The comparative
investigation was performed on standard solutions containing target C3–C9 dicarboxylic acids and on experimental particulate matter (PM) samples. Attention was focused on low-volume sampling devices
that collect small amounts of sample for organic speciation. The results show that, overall, both the techniques appear suitable
for the analysis of LMW dicarboxylic acids in atmospheric aerosols since they provide low detection limits (≤4 ng m−3) and satisfactory reproducibility (RSD% ≤ 15%). Between them, BSTFA should be the reagent of choice under the most limiting
conditions of PM filters collected by low-volume air samplers: It provides determination of all the target C3–C9 dicarboxylic acids with lower detection limits (≤2 ng m−3) and higher reproducibility (RSD% ≤ 10%)
相似文献
14.
Iparraguirre A Navarro P Prieto A Rodil R Olivares M Fernández LÁ Zuloaga O 《Analytical and bioanalytical chemistry》2012,402(9):2897-2907
Membrane-assisted solvent extraction coupled to large volume injection in a programmable temperature vaporisation injector
using gas chromatography–mass spectrometry analysis was optimised for the simultaneous determination of a variety of endocrine
disrupting compounds in environmental water samples (estuarine, river and wastewater). Among the analytes studied, certain
hormones, alkylphenols and bisphenol A were included. The nature of membranes, extraction solvent, extraction temperature,
solvent volume, extraction time, ionic strength and methanol addition were evaluated during the optimisation of the extraction.
Matrix effects during the extraction step were studied in different environmental water samples: estuarine water, river water
and wastewater (influent and effluent). Strong matrix effects were observed for most of the compounds in influent and effluent
samples. Different approaches were studied in order to correct or minimise matrix effects, which included the use of deuterated
analogues, matrix-matched calibration, standard addition calibration, dilution of the sample and clean-up of the extract using
solid-phase extraction (SPE). The use of deuterated analogues corrected satisfactorily matrix effect for estuarine and effluent
samples for most of the compounds. However, in the case of influent samples, standard addition calibration and dilution of
the sample were the best approaches. The SPE clean-up provided similar recoveries to those obtained after correction with
the corresponding deuterated analogue but better chromatographic signal was obtained in the case of effluent samples. Method
detection limits in the 5–54 ng L−1 range and precision, calculated as relative standard deviation, in the 2–25% range were obtained. 相似文献
15.
Chunguang Wang Zishou Zhang Kancheng Mai 《Journal of Thermal Analysis and Calorimetry》2011,106(3):895-903
β-nucleated PP/PET blends were prepared using nano-CaCO3 supported β-nucleating agent (β-NA), PP as matrix, and PET as dispersion phase. The effects of preparation methods, PET content, and melting temperature
on the non-isothermal crystallization behavior and the melting characteristic and polymorphic composition of PP in the blends
were investigated by differential scanning calorimeter (DSC) and wide angle X-ray diffraction (WAXD). The results indicated
that the PP crystallized predominantly in β-modification in the presence of β-NA. However, efficiency of β-NA for PP crystallization decreased with addition of PET and increasing PET contents. The β-nucleation of β-NA for PP crystallization in the blends was dependant on the preparation methods. The high β-nucleation and high β-PP content were obtained for PP/PET blend prepared at the temperature of 265 °C and added the β-NA into the blend at the temperature of 180 °C. However, the addition of β-PP or β-NA into blends at 265 °C decreased the β-nucleation, and no β-PP was formed because the β-NA mainly dispersed on the PET dispersion phase or at the interface between PP and PET. 相似文献
16.
Conditions for silylation of benzidine (BZ) and 3,3′-dichlorobenzidine (DCBZ) have been optimized. Reactivity, repeatability,
and derivative stability were compared for the silylating reagents N-Methyl-N-(trimethylsilyl)trifluoroacetamide (MSTFA) and N-Methyl-N-(tert-butyldimethylsilyl)trifluoroacetamide (MTBDMSTFA) and the catalysts 3% trimethylsilylimidazole (TMS-I) and 0.3% NH4-I–dithioerythritol. The results showed that derivatization with MTBDMSTFA/NH4-I containing 0.1 mg dithioerythritol was superior to other methods. The silylation conditions selected were reaction with
(MTBDMSTFA)–NH4I, 1000:3, with catalysis by dithioerythritol, at 80 °C for 80 min. The TBDMS derivatives of BZ and DCBZ had very good chromatographic
properties and very sensitive detection was achieved by gas chromatography with electron-impact ionization mass spectrometry
(GC-EIMS). Simultaneous determination of BZ and DCBZ in water was developed on the basis of the TBDMS derivatives. Deuterated
BZ (d8-BZ) was chosen as internal standard (IS) for analysis of water samples. BZ and DCBZ were extracted from water at pH
8.5 with dichloromethane and the extract was then dried and silylated. Recoveries of BZ and DCBZ were approximately 102 and
103% at a concentration of 2.0 ng mL−1. The coefficients of variation for BZ and DCBZ were less than 9 and 4% at concentrations of 0.2 and 0.5 ng mL−1, respectively. The method detection limits for 200 mL water were 0.004 ng mL−1 for BZ and 0.02 ng mL−1 for DCBZ. 相似文献
17.
V. N. Losev S. I. Metelitsa E. V. Elsuf’ev A. K. Trofimchuk 《Journal of Analytical Chemistry》2009,64(9):903-909
Silica gel chemically modified with N-(1,3,4-thiodiazole-2-thiol)-N′-propylurea extracted gold(III) from solutions in the range of 6 M HCl-pH 8 and silver(I) from nitric acid solutions in the
range of 6 M HNO3-pH 8 and 1–2 M HCl at 20°C with 99.0–99.9% recovery and a sorption equilibration time of 5 min. Platinum(II) was quantitatively
extracted at room temperature from solutions in the range of 4 M HCl-pH 8; the sorption equilibration time was 20 min. For
the quantitative extraction of platinum(IV), it should be reduced to platinum(II). The intense yellowish orange luminescence
(λmax (Au) = 575 nm, λmax (Ag) = 550 nm, and λmax(Pt) = 620 nm) of surface complexes at 77 K under UV irradiation was used in the development of procedures for the low-temperature
sorption-luminescence determination of gold, silver, and platinum. The detection limits were 0.15 (Au), 0.1 (Ag), and 0.05
μg (Pt) per 0.1 g sorbent. The calibration function was linear to 50 (Au, Ag) or 80 μg (Pt) per 0.1 g sorbent. The relative
standard deviation in the determination of more than 5 μg of a metal was no higher than 6%. The sorption-luminescence determination
procedures were tested in the determination of gold in gold-containing concentrates and their processing products and platinum
in alumina-platinum catalysts. 相似文献
18.
A supramolecular catalytic kinetic spectrofluorimetric method was developed for the determination of platinum(IV) and the
possible mechanism of catalytic reaction was discussed. The method was based on the fluorescence-enhancing reaction of salicylaldehyde
furfuralhydrazone (SAFH) with potassium bromate, which was catalysed by platinum(IV) in a water–ethanol medium. β–Cyclodextrin (β-CD) obviously sensitized the determination at pH 5.20 and 25°C. Under optimum conditions, the β-CD–platinum–KBrO3–SAFH supramolecular kinetic catalytic reaction system had excitation and emission maxima at 372 and 461 nm, respectively.
The linear range of this method was 0.60–180 ng ml−1 with a relative standard deviation of 1.2%, and the detection limit was 0.18 ng ml−1. Investigation of the mechanism and the effects of interferences is presented. The proposed method was applied successfully
to determine trace platinum(IV) in the chemotherapeutic drug cisplatin and serum from patients with satisfactory results.
相似文献
19.
Mehmet Gokhan Caglayan Ismail Murat Palabiyik Mustafa Bor Feyyaz Onur 《Chemical Papers》2011,65(6):754-760
Simultaneous determination of enalapril maleate (ENA) and nitrendipine (NIT) in pharmaceutical preparations was performed
using liquid chromatography (LC) and the partial least-squares-1 (PLS-1) method. In LC, the separation was achieved on a C8
column and the optimum mobile phase for good separation in a gradient elution programme was found to be acetonitrile-water
(φ
r = 81: 19) and optimum flow-rate, temperature, injection volume, and detection wavelength were set at 1.0 mL min−1, 25°C, 10 μL, and 210 nm, respectively. Dienogest was selected as an internal standard. In the spectrophotometry, a PLS-1
chemometric method was used. The absorbance data matrix related to the concentration data matrix was established by measurement
of absorbances in their zero order spectra with an increment of Δλ = 1 nm in the 220–290 nm range for ENA and with Δλ = 1 nm in the 230–290 nm range for NIT in the PLS-1 method. Following this step, calibration was established by using this
data matrix to predict the unknown concentrations of ENA and NIT in their binary mixture. These optimised methods were validated
and successfully applied to a pharmaceutical preparation in tablet form and the results were subjected to comparison. 相似文献
20.
A flow injection method is described for the determination of iron in fresh water based on potassium permanganate chemiluminescence
detection via oxidation of formaldehyde in aqueous hydrochloric acid. Total iron concentrations are determined after reducing
Fe(III) to Fe(II) using hydroxylamine hydrochloride. The detection limit (three standard deviations of blank) is 1.0 nM, with
a sample throughput of 120 h−1. The calibration graph was linear over the range (2–10) × 10−7 M (r
2 = 0.9985) with relative standard deviations (n = 5) in the range 1.0–2.3%. The effect of interfering cations (Ca(II), Mg(II), Zn(II), Ni(II), Co(II), Fe(III), Mn(II), Pb(II),
and Cu(II)) and common anions (Cl−, SO
4
2−
, PO
4
3−
, NO
3
−
, NO
2
−
, I−, F−, and SO
3
2−
) was studied at their maximum admissible concentrations in fresh water. The method was applied to fresh-water samples from
the Quetta Valley, and the results obtained (0.04 ± 0.001–0.11 ± 0.01 mg/L Fe(II)) were in reasonable agreement with those
obtained using the spectrophotometric reference method (0.05 ± 0.01–0.12 ± 0.02 mg/L Fe(II)).
The text was submitted by the authors in English. 相似文献