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Summary A method for the gas chromatographic trace analysis of underivatized nitrophenols in ground-water is presented. Using a highly
de-activated separation system a satisfactory precision for their quantitative GC analysis could be achieved by avoiding condensation
of the solvent and by fast injection of the sample. The reproducibility of the peak areas of eleven nitrophenols in ethylacetate
was <5 % RSD. Using a nitrogen-phosphorus detector detection limits were in a range from 10 to 30 pg. Within the concentration
range from 0.1 to 10 ng μl−1 the calibrations were linear with correlation coefficients >0.992.
The approach described was applied to the analysis of nitrophenols in ground-water near a former ammunition plant, after preconcentration
by continuous liquid/liquid extraction with ethylacetate. Using a GC-MS technique and retention times various nitrophenols
were identified and then quantified in the μg/L-range by applying NPD. 相似文献
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Summary The potential of large-volume PTV injection was studied for the analysis of triazine herbicides in water samples. Direct water
injection and in-vial extraction were described and compared. Detection limits were between 0.01–0.02 μg L−1 and relative standard deviations were <9%. Both methods are suitable for the analysis of triazines at ppt-level, although
in-vial extraction is favourable for water samples with relatively large amounts of matrix components. 相似文献
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Summary A method was developed for the determination of nitrobenzoic acids and nitrophenols as well as of diaminoaromatics and was
applied to the analysis of water samples from the former ammunition plant at Elsnig (Saxony, Germany).
The procedure is based on a preseparation into a neutral, an acidic and a basic fraction by multi-step extraction at different
pH values followed by HPLC analysis with UV and electrochemical detectors, coupled in series.
Applying optimized enrichment conditions, all investigated compounds were extracted from spiked distilled water with recoveries
>80% and variation coefficients <7%. Similar results were obtained with spiked ground water samples.
After enrichment, all compounds can be analysed by HPLC with UV detection at concentrations below 100 ngL−1. The electrochemical detector (ELCD) allowed a selective and sensitive detection of the nitrophenols and especially of the
diaminoaromatics and, therefore, provides, some advantages in the analysis of real samples.
Presented at the 21st ISC held in Stuttgart, Germany, 15th–20th September, 1996 相似文献
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The coupling of high-performance liquid chromatography (HPLC) and atmospheric pressure ionisation mass spectrometry (API-MS) seems to be the method of choice if good separation and selective detection of semi-volatile, thermolabile, and polar substances is required. Libraries of mass spectra will make the identification of unknown substances in complex environmental samples easier and more user-friendly. Unfortunately, existing GC-MS libraries are not applicable to HPLC-API-MS analysis. Thus, new and extensive mass spectral libraries were constructed. Several investigations of chromatographic (composition and salt concentration of the eluent) as well as mass spectrometric (orifice voltage) parameters and a few applications of real environmental samples are used to discuss the possibilities and limits of these libraries. 相似文献
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A. Prei? U. Lewin L. Wennrich M. Findeisen J. Efer 《Fresenius' Journal of Analytical Chemistry》1997,357(6):676-683
It is shown that by using high-field proton nuclear magnetic resonance (1H-NMR) spectroscopy it is possible, without prior separation, to analyse nitrophenols and other acidic nitroaromatic compounds
in the “pH 2 extract” of ammunition wastewater. The 1H-NMR chemical shifts data of a variety of reference compounds are presented. Two groundwater samples from the former ammunition
plant in Elsnig (Saxony) were analysed by 1H-NMR and also by chromatographic methods (GC/MS, HPLC). The results are compared and discussed.
Received: 17 January 1996/Revised: 15 May 1996/Accepted: 17 May 1996 相似文献
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A. Preiß U. Lewin L. Wennrich M. Findeisen J. Efer 《Analytical and bioanalytical chemistry》1997,357(6):676-683
It is shown that by using high-field proton nuclear magnetic resonance (1H-NMR) spectroscopy it is possible, without prior separation, to analyse nitrophenols and other acidic nitroaromatic compounds
in the “pH 2 extract” of ammunition wastewater. The 1H-NMR chemical shifts data of a variety of reference compounds are presented. Two groundwater samples from the former ammunition
plant in Elsnig (Saxony) were analysed by 1H-NMR and also by chromatographic methods (GC/MS, HPLC). The results are compared and discussed.
Received: 17 January 1996/Revised: 15 May 1996/Accepted: 17 May 1996 相似文献
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Summary AGC method has been developed for the analysis of tricholoroacetic acid (TCA) in water samples. It entails large-volume injection
(LVI) and programmed-temperature vaporization (PTV) of water samples, thermal decarboxylation of TCA to chloroform in the
injector, and GC-ECD analysis of the decarboxylation product. Conditions such as final injector temperature, splitless time,
and injection volume were optimized. The limit of detection is approximately 0.1 μg L−1 Several real samples were analyzed. The method presented is an easy means of determination of TCA and eliminates sample-preparation
steps such as extraction and derivatization. 相似文献
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The application of programmed temperature vaporisation (PTV) in capillary gas chromatographic analysis is reviewed. The development of the different strategies as well as the state of the art are described. As the analytes are normally enriched in the PTV insert, the quoted papers are subdivided depending on whether the enrichment was carried out from organic solvents, from water or from gaseous media. Furthermore, the possibilities of PTVs for on-line coupling with sample preparation methods or other separation techniques and their use as thermoreactors are mentioned. 相似文献