Bestimmung von Organochlorpestiziden in Schlämmen und Sedimenten

A method for the determination of organohalogens by gas chromatography using electron capture (EDC) and mass-spectrometric (MS) detection was developed for sediments from lakes and sludges of water treatment plants. The method was described and separate techniques for sample preparation were investigated to compare the retrieval rates and the best approach to the “real value”. With the help of solid-liquid-phase- and liquid-liquid-phase extraction sulphur, most of the organosulphur compounds and carbon acids were effectively removed. The compounds were identified by comparing temperature programmed retention indices with those of reference compounds and by high-resolution GC/MS.     

Polarographische Bestimmung von Schwermetallen im Klärschlamm

The differential-pulse polarography (DPP) and the stripping voltametry (SV) are investigated in detail with respect to their suitability for the quantitative detection of individual traces of heavy metals in sewage sludge. The results are checked on the basis of AAS analyses and by the standard-addition method. From the hydrochloric-acid extracts of fused sludge samples down to 1 μg/l can be detected by the SV, whereas the DPP reaches a sensitivity of 100 μg/l. The following basic electrolytes are used: Zn: 2 … 3 mol/l H₃PO₄; Cu: 0.4 mol/l K₂CO₃, 0.2 mol/l Na-K-tartrate, 0.1 mol/l HCl; Ni: 1 mol/l NH₄OH, 1 mol/l NH₄Cl, 25 ml/l triethylamine; Pb and Cd: 0.1 … 0.2 mol/l HCl.     

Die gaschromatographische Bestimmung von Diethylentriaminpentaessigsäure in Oberflächenwasser

Gaschromatographic Determination of Diethylenetriaminepentaacetic Acid in Surface Water. A method for the determination of diethylenetriaminepentaacetic acid (DTPA) is reported. The determination is based on the preconcentration on a strong base anion exchange resin, esterification with n-propanol and following gaschromatographic separation using a N-selective detector. The sensitivity of the method, including enrichment, is 1 μg/L in river water. The identity of DTPA in river water was proved by mass spectrography. The method can be used also for the quantitative determination of nitrilotriacetic acid (NTA), ethylenediaminetetraacetic acid (EDTA), cyclohexanediaminetetraacetic acid (CDTA) and ethyleneglycolbis-(2-aminoethylether)-N,N,N′,N′-tetraacetic acid (EGTA). The method was used to examine river water. An investigation along the river Rhine, taking grab samples from January and february 1992 showed that DTPA was present in some sampling places in similiar concentrations as NTA and EDTA.     

Bestimmung von Pflanzenbehandlungsmitteln in Wasser durch Online-Fest-Flüssig-Extraktion und HPLC-DAD

Determination of Pesticides in Water by On-line Solid-phase Extraction and HPLC-DAD This paper describes an HPLC on-line procedure for the determination of 29 relevant pesticides in water by diode-array detection using a compact HPLC-system with integrated column-switching. The sample – 5 mL – is injected with a large volume injection system on a precolumn cartridge (RP-C18). Enriched compounds are eluted in frontflush mode by columnswitching to a microbore column and separated with a gradient water/acetonitrile. During desorption the precolumn cartridge is heated at 80°C resulting in a comparable efficiency to the separation with direct injection. The procedure is fully automated for continuous monitoring of drinking-, ground-, and surface water with low contamination levels. Sample preparation is limited to a filtration step with an anion-exchange membrane filter to reduce natural contaminations e.g. humic acids simultaneously. For a concentration of 50 ng/L, the signal to noise ratio varies from 3:1 (Ethidimuron) up to 25:1 (Chloridazon). The standard deviations compare to the standardized HPLC-method DIN EN ISO 11369; the recovery rates are 100% and reproducible. The method was successfully tested on ruggedness with several sequences from a monitoring program. The precolumn cartridge needs replacement after 100 sample injections. Finally, this method was coupled with a benchtop mass-spectrometer (electrospray mode) without changing the chromatographic conditions. With selected ion monitoring (SIM) selectivity and detection sensitivity could be improved considerably compared to DAD-detection.     

Bestimmung von Umweltqualitätsnormen für potenziell gewässerrelevante Stoffe

With the Water Framework Directive (WFD) the European Commission (EC) is requested to define environmental quality standards for pollutants to protect aquatic life in surface waters. Quality standards have to be derived by a scientific risk assessment and should not be exceeded. The recommended quality standards are mainly based on long term toxicological tests with algae, crustaceans and fish. The lowest effect concentration is divided by an assessment factor between 10 and 1000, which considers the data quality and quantity. In this work funded by the German Länder Working Party on Water (Länderarbeitsgemeinschaft Wasser – LAWA) environmental quality standards for 40 considered relevant substances were derived for aquatic ecosystems. The data sheets cover the identification of the compounds, their behaviour in the environment (physical‐chemical properties, biotic and abiotic degradation, sorption, bioaccumulation), information about mode of action, uses, analytical determination and available quality criteria. Ecotoxicological effect concentrations for bacteria, algae, protozoa, aquatic plants, crustaceans, fish, amphibians, insects and molluscs are listed. For 17 of the 40 hazardous substances investigated, quality objectives above 1 μg/L were derived. For 12 substances the values were between 0.1 μg/L and 1 μg/L and for 5 substances lower than 0.1 μg/L. Incomplete ecotoxicological data sets of the remaining compounds do not allow the derivation of quality standards. Especially for drugs further ecotoxicological test results are needed.     

Über die Bestimmung von Aminopolycarbonsäuren durch Ionenpaarchromatographie

Determination of aminopolycarboxylic acids by ion pair chromatography. A method for the determination of aminopolycarboxylic acids, especially NTA and EDTA, is described, based on ion pair chromatography. The detection is done in UV at about 260 nm. The analytes are transformed into the Fe(III)-complexes before separation. For lower concentrations this can automatically be achieved by injecting the analyte into the Fe(III)-containing eluent. For higher concentrations, Fe(III) has to be added separately. Determination is possible down to 10 μg/1 concentration.     

Polarographische Bestimmung von Nickel und Chrom in Klärschlämmen Polarographic Determination of Nickel and Chromium in Sewage Sludge

The contents of Ni and Cr in sewage sludge with high and low amounts of heavy metals were investigated by polarography. The DIN-digestion (aqua regia) was used, and the resulting solution was treated with H₂O₂/UV (90 °C, 60 min) for further destroying of the organic material. Besides, the solution of the DIN-digestion was examined with AAS (flame) and ICP-OES. With the determination of Ni it was shown that after digestion with aqua regia no further treatment with H₂O₂/UV is necessary. Contrariwise it was found that for the determination of Cr a H₂O₂/UV photolysis is necessary followed by further steps to get good agreement with AAS and ICP results as well as with the certified values of a sludge of the Community Bureau of Standards.     

Zur derivativspektroskopischen Bestimmung der Ligninsulfonsäure in Gegenwart von Huminsäuren

A Specord M 40 device with the Date Handling 1 computer cassette was used for the derivative-spectroscopie determination of lignosulphonic acid. Because of the higher sensitivity and the better evaluable peaks, the 2nd derivation of the five possible derivations was used. The analysis method described in detail was tested with test substances on a surface water which was polluted with waste-products from the pulp industry. With the stated device parameters, the lignosulphonic acid up to 2 mg/l can be determined in the presence of humic acids and chlorolignosulphonic acids. In weakly polluted waters, as groundwaters and shore filtrates. still lignosulphonic acid concentrations of 0.1 mg/l can be detected after an adequate enrichment.     

Bestimmung der Aktivität von Belebtschlamm über die Geschwindigkeit der Biosynthese von Aminopeptidasen

The authors describe a possibility of a fast determination of the metabolic activity of various activated sludge samples. There is not used the sludge property of digestion, but the biosynthesis of aminopeptidases. Egg albumin has been found to be the optimum standard indicator. The activity of the investigated activated sludge is derived from the rate of the biosynthesis of aminopeptidases. The technique proposed can be used also for determining the toxic effects of different substances on activated sludge.