Solid-phase Enrichment Research Articles

Identification of organic contaminants in water and related matrices using untargeted liquid chromatography high-resolution mass spectrometry screening with MS/MS libraries

Nontargeted and suspect screening with liquid chromatography-high resolution mass spectrometry (LC-HRMS) has become an indispensable tool for quality assessment in the aquatic environment – complementary to targeted analysis of organic (micro)contaminants. An LC-HRMS method is presented, suitable for the analysis of a wide variety of water related matrices: surface water, groundwater, wastewater, sediment and sludge, including extracts from passive samplers and on-site solid phase enrichment, while focusing on the data processing aspect of the method. A field study is included to demonstrate the practical application and versatility of the whole process. HRMS/MS data were recorded following LC separation in both (ESI) positive and negative ionization modes using data dependent as well as data independent acquisition. Two vendor (Agilent's Personal Compound Database and Library and from National Institute of Standards and Technology) and one open (MassBank/EU) tandem mass spectral libraries were utilized for the identification of compounds via mass spectral match. The development of a novel software tool for parsing, grouping and reduction of MS/MS features in data files converted to mascot generic format (MGF) helped to substantially decrease the amount of time and effort needed for MS library search. While applying the method, in the course of the entire field study, 18771 detections (from 870 individual compounds) in total were recorded in 275 samples, resulting in 68.3 identified compounds per sample, on average. Among the top ten most frequently detected contaminants across all samples and sample types were pharmaceutical compounds carbamazepine, 4-acetamidoantipyrine, 4-formylaminoantipyrine, tramadol, lamotrigine and phenazone and industrial contaminants toluene-2-sulfonamide, tolytriazole, tris(2-butoxyethyl) phosphate and benzotriazole. Exploratory data analysis methods and tools enabled us to discover organic pollutant occurrence patterns within the comprehensive sets of qualitative data collected from various projects between the years 2018–2023. The results may be used as valuable inputs for future water quality monitoring programs.

Multiple on-line active valves based centrifugal microfluidics for dynamic solid-phase enrichment and purification of viral nucleic acid.

Point of care testing (POCT) of nucleic acids holds significant importance in the realm of infectious disease prevention and control, as well as the advancement of personalized precision medicine. Nevertheless, conventional nucleic acid testing methods continue to face challenges such as prolonged detection times and dependence on extensive specialized equipment and personnel, rendering them unsuitable for point of care applications. Here, we proposed an innovative active centrifugal microfluidic system (ACMS) for automatic nucleic acid extraction, encompassing modules for active valve control and magnetic control. An on-chip centrifugal puncture valve (PV) was devised based on the elastic tolerance differences between silicone membranes and tinfoils to release pre-embedded liquid reagents on demand. Furthermore, we have utilized the returnable valve (RV) technology to accurately control the retention and release of liquids, leveraging the high elastic tolerance of the silicone membrane. By incorporating an online controllable magnetic valve, we have achieved controlled and rapid aggregation and dispersion of magnetic beads. The final chip encapsulates multiple reagents and magnetic beads necessary for nucleic acid extraction. Upon sample addition and loading into the instrument, automated on-chip sample loading and nucleic acid extraction, purification, and collection can be accomplished within 30 minutes, halving the overall operation time and even increasing the efficiency of pseudovirus extraction by three orders of magnitude. Consequently, real-time fluorescence quantitative PCR amplification has successfully detected multiple targets of the SARS-CoV-2 virus (with an impressive detection limit as low as 10 copies per μL), along with targeted sequencing analysis yielding a conformity rate of 99%.

Construction and operation characteristics of a fully quantified low-carbon treatment process for old landfill leachate

The feasibility of utilizing a coagulation-flocculation/sedimentation-denitrification (DN)/partial nitrification (PN)-anaerobic ammonium oxidation (Anammox)-electrochemical oxidation was investigated to achieve cost-effective and fully quantified treatment of leachate from old landfills, which contains lower C/N, higher NH4+-N and refractory chemical oxygen demand (CODr). The results indicated that the coagulation-flocculation/sedimentation, which aimed to remove the CODr, not only improved the nitrogen conversion efficiencies of the following PN and Anammox by 17.5 % and 105 %, respectively, but also benefited the solid phase enrichment of PO43− and the energy consumption of subsequent advanced treatment. The optimal dose of perfluorochemical (PFC) was found to be 1200 mg/L. The optimal electrode plate spacing and current density of the electrochemical oxidation process were 25 mm and 350 A/m2, respectively, and advanced treatment of the chemical oxygen demand (COD) and total nitrogen (TN) in the wastewater was achieved within 2 h. After 190 d of operation, the effluent quality met the required discharge standards. This process has the advantage of realizing full quantified treatment of wastewater and has significant environmental benefits.

Sensitivity Enhancement for Separation-Based Analytical Techniques Utilizing Solid-Phase Enrichment Approaches and Analyte Derivatization for Trace Analysis in Various Matrices

Despite the fact that strong routine separation methodologies can give reliable specificity and validity at usual working pharmaceutical concentrations, they may fail at very low concentration levels. This poses considerable challenges for researchers investigating product purity and therapeutic drug monitoring. Sensitivity enhancement procedures are thus required to maximize the performance of separation techniques. Solid-phase extraction/solid-phase enrichment (SPE/SPEn) and pre-, post-, and in-column derivatization, as well as the use of sensitive detection devices, are the simplest strategies for improving sensitivity of separation-based analytical techniques. Large-volume injection of samples with online SPE/SPEn coupled with separation techniques increased sensitivity and improved detection as well as quantification limits without affecting peak shape and system performance. Although the primary purpose of derivatization is to improve sensitivity and selectivity, greener derivatization is growing in popularity and should be considered in analytical chemistry. In general, two strategies are essential for accomplishing greener derivatization goals. The first is the search for and use of ecologically acceptable derivatizing reagents, solvents, and reaction conditions. The second is miniaturization and automation of analytical methods. This review discusses significant advances in separation-based analytical techniques, specifically enrichment approaches and detector signal improvement for pharmaceutical quantification in various matrices at very low concentration levels. As a result of improved analytical systems setup in drug assays, the possibility of high-throughput analyses was also highlighted.

Experimental, Grand canonical Monte Carlo, and Density Functional Theory studies for comparing halloysite and kaolinite on heavy metals fate during pyrolysis of solid waste

In this study, we utilized low-cost halloysite (Hal) for the first time to enhance the solid-phase enrichment and stability of heavy metals (HMs) during solid waste pyrolysis through experimental and theoretical methods, and compared with kaolinite (Kao). Experimental results demonstrated that Hal was superior to Kao in improving the solid-phase enrichment of HMs. Specifically, the solid-phase enrichment of Cd increased by 32.6 % (500 °C) and 25.94 % (600 °C), while that of Pb and Zn increased by 17.37 %/16.83 % and 19.82 %/22.37 % (700/800 °C), respectively. Adding Hal reduced the proportion of HMs in the unstable fraction (F1 + F2), consequently lowering the environmental risk of biochar and the extractable state of HMs. Through Grand canonical Monte Carlo and Density Functional Theory (DFT) simulations, we analyzed the adsorption amounts, adsorption sites, and adsorption mechanisms of Cd/Pb compound on Hal/Kao surfaces, revealing that the primary factor influencing the adsorption performance of Hal and Kao was the difference in specific surface area. The adsorption amounts of HMs by Hal were significantly higher than Kao and decreased with increasing temperature, while the difference in adsorption performance caused by structural bending was negligible. The DFT results indicated that Cd and Pb monomers were stabilized by establishing covalent bonds with OH or reactive O atoms on the Al-(001) surface, whereas the covalent bonds with ionic bonding properties formed between Cl atoms and unsaturated Al atoms played a crucial role in stabilizing HM chlorides. Furthermore, the adsorption energy of Hal on HMs increased with the removal rate of OH. Our study highlights the potential of Hal in stabilizing HMs during pyrolysis without requiring any modifications, thereby avoiding the generation of modified waste solutions and unnecessary cost loss.

Experiment and mechanism study on enrichment of heavy metals during MSW pyrolysis by modified kaolin.

Experiment and mechanism studies on the enrichment of Pb, Cd, Zn, As, and Cr by modified kaolin were investigated during MSW (municipal solid waste) pyrolysis at 450 ~ 650°C. The results showed that γAlOK(micro- and nano-γAl2O3 by hydrothermal method modified kaolin) was relatively selective for the solid phase enrichment of Cr and As, while CaHPK (CaHPO4 impregnated modified kaolinite) was more advantageous for the adsorption of Pb and Zn, which might be related to the thermal stability of γAl2O3 and the thermal conversion of CaHPO4. Compared with the original kaolin, the adsorption and retention capacity of γAlOK for As was improved by 20 ~ 30%. Moreover, the retention rate of modified kaolin for Cd decreased from 66.75 to 30.30% at 450 ~ 650 ℃, and the effect of temperature on the volatilization of Cd was always greater than the active components on the surface of modified kaolin. In the fluidized bed experiment, the physical mixing of different modified kaolin achieves complementary advantages on the retention capacity of heavy metals. In addition, the ∆E between Ca2P2O7 and PbCl2 is smaller than that of γAl2O3 at 500 ~ 650°C, i.e., their electron transfer induction is stronger, and therefore more favorable for electron transfer and stable chemical bond formation.

New insights in hemp chemical composition: a comprehensive polar lipidome characterization by combining solid phase enrichment, high-resolution mass spectrometry, and cheminformatics.

The chemical composition of Cannabis sativa L. has been extensively investigated for several years; nevertheless, a detailed lipidome characterization is completely lacking in the literature. To achieve this goal, an extraction and enrichment procedure was developed for the characterization of phospholipids and sulfolipids. Firstly, a study on the solid-liquid extraction was performed, to maximize the recovery of the considered lipids; the best procedure consisted of a simple extraction with a mixture of methanol and chloroform (1:1, v/v). The hemp extracts were analyzed by ultra-high-performance liquid chromatography coupled to high-resolution mass spectrometry and lipids were tentatively identified by Lipostar. To improve the number of identifications, an enrichment method, based on graphitized carbon black solid phase extraction, was evaluated to fractionate phospholipids and sulfolipids into separate eluates. Recovery and matrix effects of the procedure were determined on a mixture of standard lipids, containing representative compounds for each considered lipid class. The optimized method allowed the tentative identification of 189 lipids, including 51 phospholipids and 80 sulfolipids, in the first and second fractions, respectively. The detection of only 6 sulfolipids in the first fraction and 9 phospholipids in the second fraction proved the efficacy of the fractionation method, which also allowed the number of lipid identifications to be increased compared to the same procedure without enrichment, which scored 100 lipids. Finally, a semi-quantitative analysis permitted the hemp polar lipidome to be characterized. The results of this study allow knowledge of the hemp chemical composition to be improved with a detailed description of its phospho- and sulfolipid profiles. Graphical abstract.

Optimization of an efficient solid-phase enrichment medium for Salmonella detection using response surface methodology

Salmonella is a pathogenic bacterium contributing to food poisoning and acute infectious intestinal disease. The traditional standard detection method is based on the principle of liquid phase enrichment and has a low sensitivity on targeted bacteria. We previously developed a visual immunosensor technique for efficient detection and isolation of Salmonella by applying fluorescent nanobioprobes on a specially-designed cellulose-based swab. In this study, a whole-sample solid-phase enrichment assay (WSEA) was established by optimization of the enrichment medium using response surface methodology (RSM), a powerful statistical tool for regression analysis. The optimal formula was determined as: 0.60% polyvalent poly peptone, 0.40% buffered peptone water, 0.09% ferric citrate amine, 0.24% sodium hyposulfite, 0.035% cystine, 0.01 µg mL−1 super absorbing polymer, 0.011% sodium deoxycholate, 15.00 µg mL−1 ethyl green and 30.00 µg mL−1 sodium selenite. Using this formula, Salmonella was visualized with naked eyes by relying on the indication of black spots formed on the swab. The analytic sensitivity of the assay was determined as 101 cells mL−1 with a concentration of interfering bacteria (Escherichia coli) at 105 cells mL−1. This optimized formula was confirmed with 4006 patients’ fecal samples, in which the positive rate was 0.42% by the conventional culture-based method and 2.12% by WSEA. The optimized formulation on solid phase enrichment by RSM allows relatively quick, low-cost, and large-scale detection of Salmonella, and could be used in grassroots medical institutions.

A three-pronged “Pitchfork” strategy enables an extensive description of the human membrane proteome and the identification of missing proteins

Integral membrane proteins are under-represented in standard proteomic analyses, mostly because of their low expression and absence of trypsin-cleavage sites in their hydrophobic transmembrane segments. Novel and effective strategies for membrane proteomic analysis aim at soluble N-glycosylated segments of integral membrane proteins (CSC, SPEG, N-glyco-FASP) or selectively target the hydrophobic transmembrane alpha-helical segments employing chemical peptide cleavage by CNBr (hpTC). We combined a solid phase enrichment of glycopeptides (SPEG) with a transmembrane segment-oriented hpTC method and a standard “detergent and trypsin” approach into a three-pronged “Pitchfork” strategy to maximize the membrane proteome coverage in human lymphoma cells. This strategy enabled the identification of >1200 integral membrane proteins from all cellular compartments, including 105 CD antigens, 24 G protein-coupled receptors, and 141 solute carrier transporters. The advantage of the combination lies in the complementarity of the methods. SPEG and hpTC target different sets of membrane proteins. HpTC provided identifications of proteins and peptides with significantly higher hydrophobicity compared to SPEG and detergent-trypsin approaches. Among all identified proteins, we observed 32 so-called “missing proteins”. The Pitchfork strategy presented here is universally applicable and enables deep and fast description of membrane proteomes in only 3 LC-MS/MS runs per replicate. SignificanceIntegral membrane proteins (IMPs) are encoded by roughly a quarter of human coding genes. Their functions and their specific localization makes IMPs highly attractive drug targets. In fact, roughly half of the currently approved drugs in medicine target IMPs. Our knowledge of membrane proteomes is, however, limited. We present a new strategy for the membrane proteome analysis that combines three complementary methods targeting different features of IMPs. Using the combined strategy, we identified over 1200 IMPs in human lymphoma tissue from all sub-cellular compartments in only 3 LC-MS/MS runs per replicate. The three-pronged “Pitchfork” strategy is universally applicable, and offers a fast way toward a reasonably concise description of membrane proteomes in multiple samples.

Solid phase chemistry to covalently and reversibly capture thiolated RNA.

Here, we describe an approach to enrich newly transcribed RNAs from primary mouse neurons using 4-thiouridine (s4U) metabolic labeling and solid phase chemistry. This one-step enrichment procedure captures s4U-RNA by using highly efficient methane thiosulfonate (MTS) chemistry in an immobilized format. Like solution-based methods, this solid-phase enrichment can distinguish mature RNAs (mRNA) with differential stability, and can be used to reveal transient RNAs such as enhancer RNAs (eRNAs) and primary microRNAs (pri-miRNAs) from short metabolic labeling. Most importantly, the efficiency of this solid-phase chemistry made possible the first large scale measurements of RNA polymerase II (RNAPII) elongation rates in mouse cortical neurons. Thus, our approach provides the means to study regulation of RNA metabolism in specific tissue contexts as a means to better understand gene expression in vivo.

Integrated identification and quantification of cyanobacterial toxins from Pacific Northwest freshwaters by Liquid Chromatography and High-resolution Mass Spectrometry.

The occurrence of harmful algal blooms in nutrient-rich freshwater bodies has increased world-wide, including in the Pacific Northwest. Some cyanobacterial genera have the potential to produce secondary metabolites that are highly toxic to humans, livestock and wildlife. Reliable methods for the detection of cyanobacterial toxins with high specificity and low limits of detection are in high demand. Here we test a relatively new hybrid high resolution accurate mass quadrupole time-of-flight mass spectrometry platform (TripleTOF) for the analysis of cyanobacterial toxins in freshwater samples. We developed a new method that allows the quantitative analysis of four commonly observed microcystin congeners (LR, LA, YR, and RR) and anatoxin-a in a 6-min LC run without solid-phase enrichment. Limits of detection for the microcystin congeners (LR, LA, YR, and RR) and anatoxin-a were <5 ng/L (200-fold lower than the guideline value of 1 μg/L as maximum allowable concentration of MC-LR in drinking water). The method was applied for screening freshwaters in the Pacific Northwest during the bloom and post-bloom periods. The use of high resolution mass spectrometry and concomitant high sensitivity detection of specific fragment ions with high mass accuracy provides an integrated approach for the simultaneous identification and quantification of cyanobacterial toxins. The method is sensitive enough for detecting the toxins in single Microcystis colonies.

Rapid on-line solid phase enrichment using polytetrafluoroethylene beads for chromium speciation in contaminated real water samples

Due to unchecked disposal of industrial wastes into surrounding areas, the pollution of water bodies with heavy metal toxicants has become an environmental menace. The toxicity of chromium species depends on its oxidation states, and thus regular monitoring of environmental water sources vulnerable to pollution is a must. In this regard, an on-line method for chromium speciation and determination using FAAS has been proposed. The flow-injection preconcentration mini-column containing polytetrafluoroethylene beads was used as the solid phase extractant, and chromium speciation was done by complexing Cr(III) and Cr(VI) with thiosemicarbazide chelating agent. The figures of merit for Cr(III) and Cr(VI) obtained were 61 and 56 (preconcentration factors); 0.13 and 0.14 µg L−1 (detection limits); 1.6 and 1.3% (R.S.D.). The optimized method for chromium speciation was successfully applied to industrial and Yamuna River water samples. The method validation was carried out using SRM 1640a (Trace Elements in Natural Water, NIST), and recovery > 95% was obtained.

Solid-phase enrichment and analysis of electrophilic natural products.

In search for new natural products, which may lead to the development of new drugs for all kind of applications, novel methods are needed. Here we describe the identification of electrophilic natural products in crude extracts via their reactivity against azide as a nucleophile followed by their subsequent enrichment using a cleavable azide-reactive resin (CARR). Using this approach, natural products carrying epoxides and α,β-unsaturated enones as well as several unknown compounds were identified in crude extracts from entomopathogenic Photorhabdus bacteria.

PH-controlled solid-phase enrichment of Mn(II): confirmation of the structure of the extracted ternary Mn(II) complex by single crystal X-ray structure analysis

Trace-level (μg g−1) selective separation of Mn(II) from other associated metal ions have been carried out by impregnating equimolar mixture of pyridine-2, 6-dimethanol (PDM) and thiocyanate ion on silica. The sorbent showed maximum Mn(II) sorption capacity (1.23 mmol g–1) at pH 5.0. Mn(II) was completely eluted by 8.5 mL 1.0 mol L−1 HNO3 from 1.0g sorbent and subsequently measured with flame atomic absorption spectrometer (FAAS).The structure of the extracted Mn(II) complex was established by Fourier transform infrared red spectra and confirmed by single crystal X-ray structure analysis. Thermogravimetric analysis (TGA) shows the stability of the isolated Mn(II) complex at the extraction temperature. Three sigma detection limit (N = 10) of the method was 0.6 μg mL−1 with a relative standard deviation of 0.1% (N = 10). The method has a pre-concentration factor of 105. Marginal interference from Cu2+ has been masked with NH4SCN. The developed method has been tested for trace-level separation and estimation of Mn(II) in spiked water samples.

On-line solid-phase enrichment coupled to packed reactor flow injection analysis in a green analytical procedure to determine low levels of folic acid using fluorescence detection

BackgroundAnalysis of folic acid (FA) is not an easy task because of its presence in lower concentrations, its lower stability under acidic conditions, and its sensitiveness against light and high temperature. The present study is concerned with the development and validation of an automated environmentally friendly pre-column derivatization combined by solid-phase enrichment (SPEn) to determine low levels of FA.ResultsCerium (IV) trihydroxyhydroperoxide (CTH) as a packed oxidant reactor has been used for oxidative cleavage of FA into highly fluorescent product, 2-amino-4-hydroxypteridine-6-carboxylic acid. FA was injected into a carrier stream of 0.04 M phosphate buffer, pH 3.4 at a flow-rate of 0.25 mL/min. The sample zone containing the analyte was passed through the CTH reactor thermostated at 40°C, and the fluorescent product was trapped and enriched on a head of small ODS column (10 mm x 4.6 mm i.d., 5 μm particle size). The enriched product was then back-flush eluted by column-switching from the small ODS column to the detector with a greener mobile phase consisting of ethanol and phosphate buffer (0.04M, pH 3.4) in the ratio of 5:95 (v/v). The eluent was monitored fluorimetrically at emission and excitation wavelengths of 463 and 367 nm, respectively. The calibration graph was linear over concentrations of FA in the range of 1.25-50 ng/mL, with a detection limit of 0.49 ng/mL.ConclusionA new simple and sensitive green analytical procedure including on-line pre-column derivatization combined by SPEn has been developed for the routine quality control and dosage form assay of FA at very low concentration level. The method was a powerful analytical technique that had excellent sensitivity, sufficient accuracy and required relatively simple and inexpensive instrumentation.

Research on Measuring Ultra-Trace Tombarthite Elements in Water by Separation and Enrichment of Solid-Phase Extraction-Inductively Coupled Plasma-Mass Spectrometry

Separate and enrich water samples by using solid-phase extraction, and then conduct quantitative analysis by using the ICP-MS method for 14 species of tombarthite elements. The results show that after pretreatment, ICP-MS method could be used to measure the 14 species in water samples simultaneously and it is fast, high sensitive, 50 times of enrichment, 0.2 ng/L of method detection limit after enrichment, better precision, RSD &lt; 5%; higher accuracy, and 93-104% of water recovery rate for simulative water samples.

On-line coupling of derivatization with pre-concentration to determine trace levels of methotrexate

A new simple, sensitive and precise green analytical procedure using an automated packed-reactor derivatization technique coupled with on-line solid-phase enrichment (SPEn) has been developed and evaluated to determine trace levels of methotrexate (MTX). The method was based on injection of MTX into a flowing stream of phosphate buffer (0.04M, pH 3.4), carried through the packed oxidant reactor of Cerium (IV) trihydroxyhydroperoxide for oxidative cleavage of the drug into highly fluorescent product, 2,4-diaminopteridine-6-carboxylic acid, followed by SPEn on a head of short ODS column (10mm×4.6mm i.d., 5μm particle size). The flow rate was 0.25mL/min and packed reactor temperature was 40°C. The trapped product was back-flush eluted from the ODS column to the detector by column-switching with an environmentally friendly mobile phase consisting of ethanol and phosphate buffer (0.04M, pH 3.4) in the ratio of 5:95 (v/v). The eluent was monitored at emission and excitation wavelengths of 460 and 360nm, respectively. The calibration curve was linear over the concentration range of 1.25–50ng/mL with a detection limit of 0.08ng/mL. The method was successfully applied to determine MTX in pharmaceutical formulations with mean percentage recovery ranging from 99.48 to 99.60.

Coupling of on-Line Pre-Column Oxidative Cleavage and Solid-Phase Enrichment with Liquid Chromatography Using an Eco-Friendly Analytical Procedure to Determine Low Levels of Methotrexate

A simple, sensitive and precise green high-performance liquid chromatographic method including on-line pre-column oxidation combined by column switching with a short Hypersil ODS analytical column (100 mm × 4.0 mm i.d.) for enrichment and separation was developed and validated to determine low levels of methotrexate (MTX). The method was based on oxidative cleavage of MTX into highly fluorescence products, 2,4-diaminopteridine-6-carboxaldehyde and the corresponding 2,4-diaminopteridine-6-carboxylic acid, during the flow of phosphate buffer (0.04 M, pH 3.4) containing the analyte through the packed reactor of cerium (IV) trihydroxyhydroperoxide (CTH) at a flow-rate of 0.2 mL/min and 40℃. The fluorescent products were enriched on the head of ODS analytical column for the final separation. The separation was performed at room temperature using an environmentally friendly mobile phase consisting of ethanol and phosphate buffer (0.04 M, pH 3.4) in the ratio of 10:90 (v/v). The eluent was monitored at emission and excitation wavelengths of 463 and 367 nm, respectively. The method was successfully applied, without any interference from the excipients, for the determination of drug in tablets and vials with a detection limit of 0.06 ng/mL from 500 ?L of sample MTX.

Phosphoric acid functionalized mesoporous organo-silica (EPO) as the adsorbent for in situ enrichment and isotope labeling of endogenous phosphopeptides

Ti(4+)-EPO nanoparticles were adopted as the adsorbent for in situ solid phase enrichment and isotope labeling of endogenous phosphopeptides, which has great potential application in high-throughput analyses of biological samples for screening and discovery of disease-specific biomarkers.

A new analytical methodology for a fast evaluation of semi-volatile polycyclic aromatic hydrocarbons in the vapor phase downstream of a diesel engine particulate filter

A new sampling method was developed to collect vapor-phase polycyclic aromatic compounds (PAHs) downstream of a diesel engine equipped with a diesel particulate filter (DPF). This configuration allowed us to collect separately the particulate phase, which was trapped inside the DPF, and the vapor phase, which was sampled downstream of the DPF. PAHs, which were not predominantly absorbed into the poor organic fraction of the diesel soot, but were rather physically sorbed on high energetic adsorption sites, should be extracted using very drastic extraction conditions Microwave-assisted extraction using solvent mixtures composed of pyridine and diethylamine were used to desorb particulate PAHs, and the total PAH amounts corresponded to a very low value, i.e., 8μgg−1 or 0.24μgkm−1, with a predominance of low weight PAHs. For collection of the vapor phase, gas bubbling in an aqueous medium was preferred to conventional methods, e.g., trapping on solid sorbents, for several reasons: aqueous trapping allowed us to use a solid phase enrichment process (SPE) that permitted PAH sampling at the sub-picogram levels. Consequently, low volume sampling was possible even if the sampling duration was very short (20min). Additionally, the amount of time saved for the analysis was considerable when coupling SPE to the analytical system (liquid chromatography with fluorimetric detection). Solvent consumption for the overall sampling and analytical processes was also drastically reduced. Experiments on a diesel engine showed that vapor phase samples collected downstream of the DPF contained all of the 15 target priority PAHs, even the heaviest ones. The total vapor-phase PAH amount was 6.88μgNm−3 or 10.02μgkm−1, which showed that the gaseous fraction contains more PAHs than the particulate fraction. Partitioning coefficients (Kp) were estimated showing the predominance in the vapor phase of all the PAHs. However, the DPF technology effects a considerable decrease in the total PAH emission when compared to non-equipped diesel vehicles.