F. Broto-Puig

Analysis and fate of aliphatic hydrocarbons, linear alkylbenzenes, polychlorinated biphenyls and polycyclic aromatic hydrocarbons in sewage sludge-amended soils

Abstract Different extraction and clean-up methods for the multi-residue determination of aliphatic hydrocarbons (AHCs), linear alkylbenzenes (LABs), polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) in sewage sludge-amended soil were investigated. Soxhlet extraction with dichloromethane and actived silica gel clean-up provided the best results. HRGC with FID detection, HRGC with ECD detection, and HPLC with a programmable fluorescence detection, performed accurate identification and quantification of AHCs and LABs, PCBs and PAHs, respectively. The evolution of the pollutants in sludged soil has been monitored for a 594-day period. Results indicated that AHCs, LABs and low-molecular-mass PAHs were susceptible to loss processes, whereas high-molecular-mass PAHs and PCBs were persistent.

Comparison of various extraction and clean-up methods for the determination of polycyclic aromatic hydrocarbons in sewage sludge-amended soils☆

Abstract Different extraction and clean-up methods for the determination of polycyclic aromatic hydrocarbons (PAHs) in sewage sludge-amended soil were investigated. Soxhlet plus saponification extraction and silica gel clean-up provided the best results. HPLC with a programmable fluorescence detector performed accurate identification and quantification of PAHs. The initial PAH concentrations in sewage sludge-amended soil ranged from 8 ng/g for benzo[a]fluoranthene to 93 ng/g for phenanthrene, with a total PAH concentration of 417 ng/g. The weathering of PAHs in sludged soil was monitored for a 141-day period. The results indicated that low-molecular-mass PAHs were susceptible to abiotic and biotic loss processes.

Extraction and clean-up methods for improvement of the chromatographic determination of polychlorinated biphenyls in sewage sludge-amended soils : elimination of lipids and sulphur

Abstract Different extraction and clean-up methods for the determination of polychlorinated biphenyls (PCBs) in sewage sludge-amended soil were investigated. Soxhlet extraction with hexane-acetone (41:59) and simultaneous elimination of sulphur, with recently precipitated copper, and Florisil cartridge clean-up provided the best results. High-resolution GC with electron-capture detection achieved accurate identification and quantification of the PCBs. Initial pollutant concentrations in soil amended with sewage sludge ranged from 0.5 to 94 ng/g for PCB congeners. The weathering of the PCBs in sludged soil was monitored for a 168-day period. The results indicated that PCBs were persistent.

Separation of non-ortho polychlorinated biphenyl congeners on pre-packed carbon tubes. Application to analysis in sewage sludge and soil samples

The analysis of planar (non-ortho) polychlorinated biphenyls (PCB) by HRGC-ECD or HRGC-HRMS requires a fractionation step to avoid the interferences of the bulk of PCB, usually in much higher concentration than the planar ones. In this paper, a new method, based on the fractionation of PCB on SPE commercial tubes pre-packed with Carbopack B, has been developed. After the extract has been applied on the stationary phase, the bulk of PCD are eluted with 15 ml of hexane (fraction I), mono-ortho PCB with 20 ml of hexane/toluene 99:1 (fraction II) and planar PCB with 20 ml of toluene (fraction III) in a station under vacuum. The method has been validated: accuracy (expressed as recovery in %) is >70% and precision (expressed as % RSD) is <20% considering changes of day, analyst and batch of tubes. The method is linear in the range studied. Other advantages are that the method is simple, rapid and it can be easily automated. The application of this separation to the determination of planar PCB in fly-ash extracts from an intercalibration exercise and to sewage sludge, sediment and soil samples has been successful. In addition, this method removes hydrocarbons from the planar PCB fraction and allows its concentration to very small volumes.

Application of the new C18 speedisks™ to the analysis of polychlorinated dibenzo-p-dioxins and dibenzofurans in water and effluent samples

A recently introduced disk for solid-phase extraction of pollutants from water (C18 Speedisk) has been tested for the analysis of polychlorinated dibenzo-p-dioxins (PCDD) and dibenzofurans (PCDF). The complete procedure of analysis has been validated with spiked deionized water. The accuracy, expressed as recovery for the sum of 2,3,7,8-substituted congeners. is 92% and the precision, expressed as the RSD of reproducibility, is 5.8%. The limit of detection (LOD), using 2 l of water, is 4.2 pg/l (0.6 pg ITEQ/l) for the sum of 2,3,7,8-substituted congeners. Actually, the C18 Speedisks have substituted the use of other C18 membrane disks in our laboratory because they allow the fast and efficient analysis of samples with high content of suspended material and reduce the time of elution of free-particulate samples. These disks have been successfully applied to the analysis of water from different sources and with very different physical and chemical characteristics: seawater, rain water, an industrial effluent, a landfill leachate and the inlet and chlorinated and non-chlorinated outlet water from a wastewater treatment plant.

The fate of petroleum aliphatic hydrocarbons in sewage sludge-amended soils

Abstract Sewage sludge-amended soils containing indigenous and spiked petroleum hydrocarbons (gas-oil and lubricating oil) were monitored for aliphatic hydrocarbons weathering. Results indicated that n-alkanes were lost by abiotic and biotic processes, the former being more important for the short-chain alkanes. Their half-lives were from 2.7 to 5.9 days, depending on the initial concentration.

Development and validation of a method for analyzing polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans in sewage sludge samples

SummaryA method has been developed for the analysis of polychlorinated dibenzo-p-dioxins (PCDD) and dibenzofurans (PCDF) in sewage sludge samples. It was found that PCDD/F are best Soxhlet extracted from the matrix with toluene for 24h, after having tested other solvents (dichloromethane and hexane/acetone 41/59) and other extraction times. Several clean up steps (sulfuric acid, multilayer silica and Florisl columns) and concentration are required prior to analysis of the extract by high resolution gas chromatography-high resolution mass spectrometry (HRGC-HRMS). The complete procedure has been validated and the accuracy and precision data (repeatability and reproducibility) are given. The method is linear in the range studied and the limit of detection ranges between 0.2 and 2.2 pg g−1 of dry matter for the 2,3,7,8-substituted congeners. Moreover, the suitability of the method has been checked in an international interlaboratory comparison. The successful application of this method to several samples from Catalan and Dutch urban wastewater treatment plants was demonstrated.