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1.
G. C. Galletti Paola Bocchini Darinn Cam Giuseppe Chiavari Rocco Mazzeo 《Fresenius' Journal of Analytical Chemistry》1997,357(8):1211-1214
A black crust sample from the stony central portal of the abbey of St. Denis, France, was analyzed by chromatographic and
spectroscopic techniques to determine whether it was due to atmospheric pollution or to the degradation of a past restoration
treatment. Stratigraphic surveys by optical microscopy, Fourier-transform infrared spectroscopy (FTIR), scanning electron
microscopy/energy dispersive X-ray fluorescence (SEM/EDX) and pyrolysis/gas chromatography/mass spectrometry (PY/GC/MS) were
consistent in ascribing the bulk of the crust to gypsum (CaSO4 ⋅ 2H2O) with inclusion of carbon particulate. The organic fraction was a minor constituent of the black crust. Hence, the deterioration
by an organic substance used in the past to restore the building was ruled out.
Received: 23 May 1996/Revised: 29 July 1996/Accepted: 1 August 1996 相似文献
2.
G. C. Galletti Paola Bocchini Darinn Cam Giuseppe Chiavari Rocco Mazzeo 《Analytical and bioanalytical chemistry》1997,357(8):1211-1214
A black crust sample from the stony central portal of the abbey of St. Denis, France, was analyzed by chromatographic and
spectroscopic techniques to determine whether it was due to atmospheric pollution or to the degradation of a past restoration
treatment. Stratigraphic surveys by optical microscopy, Fourier-transform infrared spectroscopy (FTIR), scanning electron
microscopy/energy dispersive X-ray fluorescence (SEM/EDX) and pyrolysis/gas chromatography/mass spectrometry (PY/GC/MS) were
consistent in ascribing the bulk of the crust to gypsum (CaSO4 ⋅ 2H2O) with inclusion of carbon particulate. The organic fraction was a minor constituent of the black crust. Hence, the deterioration
by an organic substance used in the past to restore the building was ruled out.
Received: 23 May 1996/Revised: 29 July 1996/Accepted: 1 August 1996 相似文献
3.
Pilar Bermejo-Barrera Carmen Barciela-Alonso Consuelo González-Sixto Adela Bermejo-Barrera 《Analytical and bioanalytical chemistry》1997,357(3):274-278
A method was optimized for the determination of tin in slurries of marine sediment samples using palladium-magnesium nitrate
as chemical modifier and Triton X-100 (0.1%) surfactant as stabilizer. To obtain a complete pyrolysis of the slurry sample,
two charring steps were used, the first at 480 °C and the second at 1300 °C. The precision and accuracy of the method were
studied using the Reference Material PACS-1 (marine sediment) from National Research Council Canada. The detection limit (LOD)
was 57.6 μg kg-1. The method was applied to the determination of tin in marine sediment samples from the Galicia coast.
Received: 16 February 1996/Revised: 26 March 1996/Accepted: 12 April 1996 相似文献
4.
Patterns of volatile ECD-active substances in marine air at the ultra trace level were investigated. The protocol used carbon
based adsorbents, thermodesorption and thick film HRGC-ECD together with a second ECD in line with oxygen doped make-up gas.
The latter ECD mode leads to an increased sensitivity for chloromethane, dichloromethane, and other important chlorinated
substances with an otherwise low response at an ECD driven with oxygen-free nitrogen or argon/methane. The experimental set-up
is easily to employ. Air samples were taken on two cruises of the German research vessel R/V “Polarstern” in the Atlantic
Ocean to determine the background pattern of all volatile halocarbons from CF3Cl to CHI3 in marine air.
Received: 28 July 1999 / Revised: 26 September 1999 / Accepted: 4 October 1999 相似文献
5.
E. Bobrowska-Grzesik Andrzej M. Grossman 《Analytical and bioanalytical chemistry》1997,357(7):1000-1001
Second order derivative spectrophotometry was applied to the determination of nitrite and nitrate ions in bath solutions
for alkaline black-oxidation of steel. The measurements were directly taken after dilution of the samples at λ = 336.4 nm
for NO3
– and λ = 390 nm for NO2
–. The method was checked on artificial mixtures and applied to real samples containing approximately 5.5% NaNO2 and 6% NaNO3. The results agree well with those obtained by the standard manganometric method.
Received: 8 July 1996 / Revised: 24 September 1996 / Accepted: 28 September 1996 相似文献
6.
J. J. Berzas Nevado J. Rodríguez Flores M. J. Villaseñor Llerena 《Analytical and bioanalytical chemistry》1997,357(7):989-994
Adsorptive stripping voltammetry was used for the determination of trace amounts of the dye Tartrazine (E-102) by square-wave
(SWS) and differential pulse techniques (DPS). Its adsorptive voltammetric behaviour was investigated at different pH media.
NH4Cl/NH3 buffer solution was chosen as the most suitable, taking into account the sensitivity and definition of the reduction peaks
obtained. The effects of the experimental parameters on the determination are discussed. Standard deviations of 3.3% and 2.6%
were obtained by SWS and DPS for 100 and 50 μg/L Tartrazine solutions, respectively (n = 10). Both methods were applied to
determine the dye in several commercial soft drinks, containing very small amounts of it. Measurements were made directly
in the commercial samples. A comparison of the results obtained by the proposed voltammetric methods with those of an HPLC
method was also made. Good correlations between the voltammetric results and the values supplied by the manufacturer were
found, whereas recoveries of the same order of magnitude were obtained by the HPLC method.
Received: 23 May 1996 / Revised: 5 July 1996 / Accepted: 10 July 1996 相似文献
7.
Seven rain and 2 snow samples collected in October and November 1993 were analyzed by GFAAS. Manganese concentrations ranging
from 0.3 to 11.3 μg/L were found. pH-values (4.04–4.89, mean 4.52) and redox potentials (528–665 mV, mean 581 mV) were additionally
determined. This is important with respect to a qualified specification of Mn in atmospheric samples. A 0.45 μm-filtration
of the samples prior to GFAAS-analysis showed the same manganese concentrations in the filtrate as in the unfiltered samples.
Hence, the amount of solid Mn species in the investigated samples is negligible. For an examination of the oxidation state
of Mn some investigations concerning the stability of Mn(III) were carried out. They indicated that Mn(III) is unstable under
atmospheric conditions. For checking whether all the manganese in rainwater exists as Mn(II), a sensitive IC method for the
detection of Mn(II) was developed. By adapting a photometric procedure based on the oxidation of Leucomalachite Green (LMG)
to Malachite Green (MG) by permanganate (MnO-
4) to the IC-flow-through-system, a limit of determination of 1 μg/L Mn(II) could be achieved. A comparison of the IC measurements
with GFAAS-results of the filtered samples showed agreeing results. Thus, manganese in rainwater and snow exists entirely
as soluble Mn(II).
Received: 24 May 1996/Revised: 7 July 1996/Accepted: 14 July 1996 相似文献
8.
Seven rain and 2 snow samples collected in October and November 1993 were analyzed by GFAAS. Manganese concentrations ranging
from 0.3 to 11.3 μg/L were found. pH-values (4.04–4.89, mean 4.52) and redox potentials (528–665 mV, mean 581 mV) were additionally
determined. This is important with respect to a qualified specification of Mn in atmospheric samples. A 0.45 μm-filtration
of the samples prior to GFAAS-analysis showed the same manganese concentrations in the filtrate as in the unfiltered samples.
Hence, the amount of solid Mn species in the investigated samples is negligible. For an examination of the oxidation state
of Mn some investigations concerning the stability of Mn(III) were carried out. They indicated that Mn(III) is unstable under
atmospheric conditions. For checking whether all the manganese in rainwater exists as Mn(II), a sensitive IC method for the
detection of Mn(II) was developed. By adapting a photometric procedure based on the oxidation of Leucomalachite Green (LMG)
to Malachite Green (MG) by permanganate (MnO-
4) to the IC-flow-through-system, a limit of determination of 1 μg/L Mn(II) could be achieved. A comparison of the IC measurements
with GFAAS-results of the filtered samples showed agreeing results. Thus, manganese in rainwater and snow exists entirely
as soluble Mn(II).
Received: 24 May 1996/Revised: 7 July 1996/Accepted: 14 July 1996 相似文献
9.
A. N. Araújo Joan Gracia Jose´ L. F. C. Lima Manel Poch M. Lu´cia M. F. S. Saraiva 《Analytical and bioanalytical chemistry》1997,357(8):1153-1156
A procedure is described for the colorimetric determination of iron in infant fortified formulas based on sequential injection
analysis (SIA). Iron(III) complexation with thiocyanate is used as colour developing reaction. The system enables the determination
of iron in the samples (after digestion by dry ashing and treatment with 0.2 mol/L nitric acid in the range of 0.50–20.0 mg/L,
consuming 140 μL of the sample and 8 mg thiocyanate per determination. The reactor geometry and the adjustment of the ionic
content of the calibration solutions is important for the accuracy of the results. A regression line according to the equation
[Fe(III) (mg/L)]SIA=−0.3(±0.4)+1.03(±0.04) [Fe(III) (mg/L)]FAAS was obtained after comparative analysis of a set of 12 samples. The measurement rate was 34 s, thus allowing to analyze 100
samples per hour with a relative standard deviation lower than 2%.
Received: 30 July 1996/Revised: 1 October 1996/Accepted: 4 October 1996 相似文献
10.
The analysis of 31P and 15N NMR data of a series of 40 iminophosphines R-P=N-R′ reveals that the E/Z-stereochemistry of the PN double bond can be predicted
on the basis of a simultaneous comparison of the values of δ31P and 1JPN.
Received: 31 May 1996/Revised: 2 July 1996/Accepted: 5 July 1996 相似文献
11.
The analysis of 31P and 15N NMR data of a series of 40 iminophosphines R-P=N-R′ reveals that the E/Z-stereochemistry of the PN double bond can be predicted
on the basis of a simultaneous comparison of the values of δ31P and 1JPN.
Received: 31 May 1996/Revised: 2 July 1996/Accepted: 5 July 1996 相似文献
12.
Francisco Laborda María V. Vicente José M. Mir J. R. Castillo 《Analytical and bioanalytical chemistry》1997,357(7):837-843
Chromatographic effluents were on-line analyzed by Zeeman-ETAAS, using a flow-through cell placed in a graphite furnace autosampler
as interface. To obtain high sampling rates, the use of fast graphite furnace programmes was studied. Conventional programmes
of 96 s were reduced to 18 s by using hot injection (120 °C) and reducing the charring step to 2 s. The increase of the injection
volume from 20 to 60 μl lengthened the programme to 46 s. Nickel had to be added to get a comparable response for both inorganic
and organic selenium species (selenite and selenomethionine) and to reduce the interferent effect produced in presence of
the chromatographic eluent (TRIS 0.01 mol l-1, NH4NO3 0.1 mol l-1, pH 7). The optimized conditions were applied to the speciation of selenium in human erythrocyte lysates by size exclusion
LC-ETAAS. Using a high performance size exclusion column selenium could be assigned to proteins of 100 and 35 kDa. Detection
limits in the range of 1 ng (2 μg l-1 for 500 μl injection volume) were obtained for the combined technique.
Received: 9 October 1996/Revised: 8 July 1996/Accepted: 14 July 1996 相似文献
13.
A new procedure for the field characterization of the available amount of molybdenum in soil extract is described. It is
based on the preconcentration of the Mo(V)-SCN– complex into toluene solution of N-octylacetamide (OAA) and subsequent heating of the extract for ≈ 10 min at 60° C over
a water bath. The molar absorptivity of the complex is (3.50) × 104 1 mole–1 cm–1 at λmax 470 nm. The detection limit of the method is 4 ppb Mo. It provides a significantly increased tolerance limit for iron (up
to 1000 ppm) and is applicable to the field characterization of Mo in soil extracts.
Received: 29 May 1996 / Revised: 17 July 1996 / Accepted: 19 July 1996 相似文献
14.
B. W. Wenclawiak Torsten Hees Corinna E. Z?ller Hans-Peter Kabus 《Fresenius' Journal of Analytical Chemistry》1997,358(4):471-474
An on-line system of supercritical fluid extraction (SFE) and high performance liquid chromatography (HPLC) via solid phase
extraction (SPE) is described for the determination of palladium and rhodium 2,2,6,6-tetramethyl-3,5-heptanedione-(thd) as
well as rhodium-acetylacetonate-(acac) and benzylacetonate-(bzac) chelates. The chelates were extracted with supercritical
CO2 from sand and humic acid, concentrated on SPE cartridges and analysed with HPLC. Two cartridge materials were tested and
compared to off-line trapping. The percentage of the breakthrough and cartridge retained material were measured in liquid
dichloromethane. The SFE conditions could be optimized to separate metal chelates during the extraction. The supercritical
fluid (SF) behaviour of different ligands on rhodium were investigated.
Received: 19 July 1996/Revised: 11 December 1996/Accepted: 14 December 1996 相似文献
15.
An automated procedure for correcting the interference due to mixing the reagents in the determination of ATP by a bioluminescent
technique is described. The measurements were performed by an in-house interfaced PC photometer. An automated procedure based
on a robust regression method and outliers detection was applied to exclude the time of the mixing of the reagents from the
global time of reaction. In fact the mixing of the reagents is responsible of the poor analytical precision (RSD%>25) and
low sensitivity (limit of detection≈2×10-8 mol/l). By this procedure, the precision (RSD%<7) and sensitivity (limit of detection≈8×10-10 mol/l) were improved. The method was applied to the determination of ATP in marine sediments and good recovery within 90–108%
was obtained. For non-polluted samples the measurement can be carried out by direct comparison with standard solutions. The
standard addition procedure is recommended for polluted samples.
Received: 25 April 1996/Revised: 28 June 1996/Accepted: 3 July 1996 相似文献
16.
M. Mecozzi Marina Amici Giovanni Visco 《Fresenius' Journal of Analytical Chemistry》1997,357(6):747-751
An automated procedure for correcting the interference due to mixing the reagents in the determination of ATP by a bioluminescent
technique is described. The measurements were performed by an in-house interfaced PC photometer. An automated procedure based
on a robust regression method and outliers detection was applied to exclude the time of the mixing of the reagents from the
global time of reaction. In fact the mixing of the reagents is responsible of the poor analytical precision (RSD%>25) and
low sensitivity (limit of detection≈2×10-8 mol/l). By this procedure, the precision (RSD%<7) and sensitivity (limit of detection≈8×10-10 mol/l) were improved. The method was applied to the determination of ATP in marine sediments and good recovery within 90–108%
was obtained. For non-polluted samples the measurement can be carried out by direct comparison with standard solutions. The
standard addition procedure is recommended for polluted samples.
Received: 25 April 1996/Revised: 28 June 1996/Accepted: 3 July 1996 相似文献
17.
An in-line flow injection extraction-preconcentration procedure for the determination of total phenols in oil is described.
The reaction between phenolic compounds and 4-aminoantipyrine in the presence of K2S2O8 as oxidizing reagent was used. The phenols were extracted and preconcentrated from a xylene solution by using a more selective
passive hydrophilic Spectrapor membrane which also removed interferences. The phenols deprotonated after diffusion to the
basic acceptor stream and the preconcentrated phenolate was injected into a carrier stream containing 4-aminoantipyrine as
colour reagent. The carrier stream then merged with the oxidant stream, followed by detection at 500 nm. The system was suitable
for the determination of total phenols in oil at a sampling rate of 12 samples per hour with an RSD of better than 1.3%. The
detection limit was 0.09 mg/l for phenol, 0.18 mg/l for o-cresol and 0.02 mg/l for m-cresol. The results of the proposed system
compared favourably with a standard manual 4-AAP method and a standard GC procedure.
Received: 30 July 1996/Accepted: 25 August 1996 相似文献
18.
19.
Sri Juari Santosa S. Tanaka Kazuo Yamanaka 《Fresenius' Journal of Analytical Chemistry》1997,357(8):1122-1127
A sensitive method has been developed for the sequential determination of V, Mn, Fe, Co, Ni, Cu, Zn, Mo and Sb in sea water
using inductively coupled plasma mass spectrometry (ICP-MS) after electrothermal vaporization of their dithiocarbamate complexes
in methyl isobutyl ketone (MIBK). After complexion with sodium diethyldithiocarbamate (NaDDTC), all trace analyte elements
were simultaneously separated from sea water matrix and concentrated 20 fold in a single extract of MIBK, followed by introduction
of 10 μL of the extract into argon plasma using a pyrolytic graphite rod electrothermal vaporizer (ETV). Sensitivity enhancement
due to chemical modification using a mixed modifier of Pd(NO3)2-Mg(NO3)2 was observed for all the elements. The limits of detection ranged from 2 ng/L for Co to 329 ng/L for V. For replicate determinations
of the elements in sea water, the repeatability was within 10% (as a coefficient variation), except for V (12.8%). The recovery
test performed on a sea water sample resulted in a range value from 87% for Sb to 119% for V. The method has been successfully
applied to sea water samples collected from the surface to the depth of 5000 m at a sampling station in the northwest Pacific
Ocean.
Received: 1 July 1996/Revised: 24 September 1996/Accepted: 25 September 1996 相似文献
20.
Dong-yuan Wang Y. Zhao Jin-gou Xu Xiang-qun Guo 《Fresenius' Journal of Analytical Chemistry》1997,358(4):514-518
A sensitive method using fluorescence quenching for the determination of nucleotides (ATP, ADP, AMP, CTP, UTP) and polynucleotides[poly(A),
poly(I), poly(U)] is proposed. It is based on the ability of nucleotides and polynucleotides to inhibit the formation of a
strongly fluorescent complex of Tb3+ ion with Tiron. The possibilities of spectrofluorimetric measurements of these systems were studied under optimal conditions
(pH 6.9 in hexamethylene tetramine-HCl buffer, 1.2×10-6 mol/L of Tb3+, 4.0×10-6 mol/L of Tiron, λex=317 nm, λem=546 nm). The results showed that the Tb3+-Tiron complex could be used as a fluorescence test for the phosphate moieties of nucleotides and polynucleotides. The detection
limits are 0.3, 1.2, 3.7, 0.2, 0.3, 1.1, 0.6 and 0.9 ng/mL for ATP, ADP, AMP, CTP, UTP, poly(A), poly(I), and poly(U), respectively.
The relative standard deviations (6 replicates) are within 4.0% in the middle of the linear range. The fluorescence quenching
mechanism of these systems is also discussed.
Received: 16 July 1996 / Revised: 13 November 1996 / Accepted: 13 November 1996 相似文献