Sampling and determination of formaldehyde using solid-phase microextraction with on-fiber derivatization

Gaseous formaldehyde is sampled by derivatization with o-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine hydrochloride (PFBHA) adsorbed onto poly (dimethylsiloxane)/divinylbenzene solid-phase microextraction fibers. The product of the reaction is an oxime which is thermally very stable and insensitive to light. The oxime can be analyzed by gas chromatography with flame ionization detection and other detectors. Loading PFBHA on the fiber is by room-temperature headspace extraction from aqueous solutions of PFBHA. The process of loading and desorption of unreacted PFBHA, and oxime formed, is both highly reproducible and reversible, with more than 200 loading, sampling, and analysis steps possible with one fiber. The standard formaldehyde gas concentrations studied ranged from 15 to 3200 ppbv with sampling times from 10 s to 12 min. Quantification can be achieved via interpolation from calibration curves of area counts as a function of formaldehyde concentration for a fixed sampling time. Sampling for 10 s yields a method detection limit of 40 ppbv and at 300 s the method detection limit is 4.6 ppbv. This is equal to or better than all other conventional grab sampling methods for gaseous formaldehyde employing sampling trains or passive sampling techniques. Alternatively, gaseous formaldehyde can be quantified with an empirically established apparent first-order rate constant (0.0030 ng/(ppbv s) at 25 °C) for the reaction between sorbed PFBHA and gaseous formaldehyde. This first-order rate constant allows for quantitative analyses without a calibration curve, only requiring detector calibration with the oxime. This new method was used for the headspace sampling of air known to contain formaldehyde, as well as other carbonyl compounds, and from various matrixes such as cosmetics and building products.     

A sensitive method for the quantification of acrolein and other volatile carbonyls in ambient air

Acrolein, an unsaturated aldehyde found in both indoor and outdoor air, is considered one of the greatest noncancer health risks of all organic air pollutants. Current methods for determining acrolein often employ sorbent-filled cartridges containing a carbonyl derivatizing agent (e.g., dinitrophenylhydrazine). These methods are of limited use for unsaturated compounds due to the formation of unstable derivatives, coelution of similar compounds, long sample collection times, and ozone interferences that result in poor sensitivity, selectivity, and reproducibility. The goal of this research was to develop an analytical method for determining ppt concentrations of acrolein and other carbonyls in air with short sampling times (10 min). The method uses a mist chamber to collect carbonyls by forming water-soluble carbonyl-bisulfite adducts. The carbonyls are then liberated from the bisulfite, derivatized, and quantified by gas chromatography/electron capture negative ionization mass spectrometry. The method was applied to determine atmospheric acrolein concentrations at three sites in northern California reflecting hemispheric background concentrations, biogenic-dominated regions, and urban environments. The resulting acrolein concentrations were 0.056, 0.089, and 0.29 microg/m3, respectively, which are all above the EPA Reference Concentration of 0.02 microg/m3. The minimum detection limit of 0.012 microg/m3 is below that of other published methods. Methacrolein, methyl vinyl ketone, crotonaldehyde, glyoxal, methyl glyoxal, and benzaldehyde were also quantified.     

On-line derivatization for resonance-enhanced multiphoton ionization time-of-flight mass spectrometry: detection of aliphatic aldehydes and amines via reactive coupling of aromatic photo ionization labels

Resonance-enhanced multiphoton ionization time-of-flight mass spectrometry (REMPI-TOFMS) is a powerful technique for the on-line analysis of aromatic compounds with unique features regarding selectivity and sensitivity. Aliphatic compounds, however, are difficult to address by REMPI due to their unfavorable photo ionization properties. This paper describes the proof of concept for an on-line derivatization approach for converting nonaromatic target analytes into specific, photoionizable aromatic derivatives that are readily detectable by REMPI-TOFMS. A multichannel silicone trap or poly(dimethylsiloxane) (PDMS) open tubular capillary was used as a reaction medium for the derivatization of volatile alkyl aldehydes and alkylamines with aromatic "photoionization labels"and to concentrate the resulting aromatic derivatives. The aldehydes formaldehyde, acetaldehyde, acrolein, and crotonal, which when underivatized are poorly detectable by REMPI, were converted into their easily photoionizable phenylhydrazone derivatives by the on-line reaction with phenylhydrazine as reagent. Similarly, the methyl-, ethyl-, propyl-, and butylamines were converted into their REMPI-ionizable benzaldehyde alkylimine derivatives by the on-line reaction with benzaldehyde as reagent. The derivatives were thermally desorbed from the PDMS matrix and transferred into the REMPI-TOFMS for detection. The REMPI-TOFMS detection limits obtained for acetaldehyde; acrolein; crotonal; and methyl-, ethyl-, propyl-, and butylamine using this photo ionization labeling method were in the sub-parts-per-million range and, thus, readily below the permissible exposure limits set by OSHA.     

Carbonyl compounds in the roadside environment of Hong Kong

The levels of carbonyl compounds were determined at the roadside urban station at the Hong Kong Polytechnic University (HKPU) campus during January 2002 to February 2002. Nine carbonyl compounds were quantified in this study. Temperature and solar radiation were found to affect the photochemical reactions of the carbonyls. Formaldehyde/acetaldehyde ratio ranged from 1.27 to 1.35. Strong correlations between formaldehyde and acetaldehyde were found, in the time period 1800-2100, which indicated that they were originated from the same sources during this time period. Roadside carbonyl samples were also collected at four other roadside environments during 2001. Kwai Chung (KC) station showed the highest average formaldehyde and acetaldehyde concentrations due to its highest traffic flow, especially for diesel vehicles. High concentration of toluene emitted from gasoline-fueled vehicles was believed to be the cause of high benzaldehyde level at the Central (CT) station through the photochemical oxidation of toluene. The average concentrations of formaldehyde and acetaldehyde in Hong Kong are well within the ranges reported in roadside environments of other urban cities. However, Mexico City in Mexico and Cairo in Egypt had much higher concentration levels of formaldehyde and acetaldehyde than in Hong Kong roadside environment due to the incomplete combustion of different fuel compositions.     

Simultaneous determination of ozone and carbonyls using trans-1,2-bis(4-pyridyl)ethylene as an ozone scrubber for 2,4-dinitrophenylhydrazine-impregnated silica cartridge

A new method for the simultaneous determination of ozone and carbonyls in air using a two-bed cartridge system has been developed. Each bed consists of reagent-impregnated silica particles. The first contains trans-1,2-bis-(4-pyridyl) ethylene (BPE) while the second contains 2,4-dinitrophenylhydrazine (DNPH). Air samples are drawn through the cartridge first through the BPE and then through the DNPH. Ozone in the air sample is trapped in the first bed by the BPE-coated silica particles and produce pyridine-4-aldehyde. Airborne carbonyls pass unimpeded thorough the BPE and are trapped in the second bed by the DNPH-coated silica particles. They produce carbonyl 2,4-DNPhydrazones. DNPH and carbonyl 2,4-DNPhydrazones are not influenced by ozone because of effective trapping by the BPE. Extraction is performed in the direction reverse to air sampling. When solvent is eluted through the BEP/DNPH cartridge, excess DNPH is washed into the BPE bed where it reacted with pyridine-4-aldehyde and forms the corresponding hydrazone derivative. All of the hydrazones derived from airborne carbonyls and pyridine-4-aldehyde (derived from ozone) are completely separated and measured using high-performance liquid chromatography. An Ascentis RP-Amide column is used, and the mobile phase is 40% aqueous acetonitrile containing 2 mmol/L ammonium acetate. The use of a BPE/DNPH cartridge has made possible the simultaneous determination of ozone and carbonyls. A separate ozone scrubber is not necessary with the BPE/DNPH cartridge because the BPE portion of the sampler serves this function.     

Development of a solid-phase microextraction GC-NPD procedure for the determination of free volatile amines in wastewater and sewage-polluted waters.

An analytical procedure for the determination of free volatile C1-C6 amines in aqueous matrixes has been developed and applied to their determination in waste-water, primary and secondary effluents, and sewage-polluted river samples. The developed analytical procedure involves headspace sampling using solid-phase microextraction with a poly(dimethylpolysiloxane) coating (100 microns) followed by GC-NPD determination and GC/MS confirmation using a tailor-made PoraPLOT amines capillary GC column for volatile amines. Procedural detection limits were compound dependent but ranged from 3 to 56 micrograms L-1, being close to or lower than the odor threshold concentration, and the reproducibility was ca. 15% (N = 5) in real water samples. The developed analytical procedure is solvent free, cost-effective (no cryogenic trap needed), and faster than existing methods because no derivatization step is involved in the determination. Linearity was compound dependent but ranged at least from 50 to 600 micrograms L-1.     

The pollution status of atmospheric carbonyls in a highly industrialized area

The concentrations of 12 carbonyls in ambient air were measured from multiple locations of an urban area in the surroundings of a large industrial complex (August 2004 to September 2005). According to our field study, acetaldehyde (19.5+/-10.6 ppb) and formaldehyde (19.3+/-10.1 ppb) were found to be the two most abundant species followed by propionaldehyde (19.0+/-23.2 ppb), acetone (15.9+/-15.2 ppb) and butyraldehyde (13.0+/-19.8 ppb). An examination of spatial variation patterns of carbonyls, when compared between industrial sites versus non-industrial sites, indicates that the mean values for each site type are statistically insignificant in most cases. In contrast, a comparison of temporal variation patterns indicates a fairly distinctive trend with the relative enhancement during summer (over winter) and/or daytime (over nighttime). The computation of the concentration ratios between some indicative species (e.g., formaldehyde/acetaldehyde and acetaldehyde/propionaldehyde) is unique enough to describe the pollution status of carbonyl species in the study area. Moreover, the relative contribution of several offensive odorous components (e.g., acetaldehyde, propionaldehyde, and butyraldehyde) is fairly strong, while their emissions are suspected to come from a substantial use of ethanol. The results of the present study thus confirm that the acquisition of ambient carbonyl concentration data is fairly useful for distinguishing the pollution status and the associated odor-related impacts.     

Analysis of human skin emanations by gas chromatography/mass spectrometry. 2. Identification of volatile compounds that are candidate attractants for the yellow fever mosquito (Aedes aegypti)

Volatile compounds emanated from human skin were studied by gas chromatography/mass spectrometry (GC/MS). The purpose of this study was to identify compounds that may be human-produced kairomones which are used for host location by the mosquito, Aedes aegypti (L.). The procedure used to collect volatiles was chosen because of prior knowledge that attractive substances can be transferred from skin to glass by handling. Laboratory bioassays have shown that the residuum on the glass remains attractive to mosquitoes until the compounds of importance evaporate. The sampling and analytical procedures modeled the above-cited process as closely as possible except that the evaporation of compounds from the glass surface was accomplished by thermal desorption from glass beads in a heated GC injection port. This made possible the solventless injection of volatiles onto the column. The compounds were cryofocused on the head of the column with liquid nitrogen prior to GC separation. A single stage of mass spectrometry on a triple quadrupole instrument was used for mass analysis. A combination of electron ionization and pulsed positive ion/negative ion chemical ionization modes on two different GC columns (one polar, one relatively nonpolar) was used to identify most of the 346 compound peaks detected by this technique.     

Development of a compound-specific carbon isotope analysis method for atmospheric formaldehyde via NaHSO3 and cysteamine derivatization

A novel method has been developed for the compound-specific carbon isotope analysis of atmospheric formaldehyde using gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS). The method allows the determination of the delta13C value for atmospheric formaldehyde at nanogram levels with higher precision and lower detection limit. In the present work, atmospheric formaldehyde was collected using NaHSO3-coated Sep-Pak silica gel cartridges, washed out by water, then derivatized by cysteamine of known delta13C value, and the delta13C value of its derivative (thiazolidine) determined by GC/C/IRMS. Finally, the delta13C value of atmospheric formaldehyde could be calculated by a simple mass balance equation between formaldehyde, cysteamine, and thiazolidine. Using three formaldehydes with different delta13C values, calibration experiments were carried out over large ranges of formaldehyde concentrations. The carbon isotope analysis method achieved excellent reproducibility and high accuracy. There was no carbon isotopic fractionation throughout the derivatization processes. The differences in the carbon isotopic compositions of thiazolidine between the measured and predicted values were always <0.5 per thousand, within the specifications of the GC/C/IRMS system. The present method was also compared with the previous 2,4-dinitrophenylhydrazine derivatization method, and this method could be performed with lower analytical error and detection limit. Using this method, four 6-h ambient atmospheric formaldehyde samples were consecutively collected from 8 to 9 March 2005. The results showed that the delta13C values of atmospheric formaldehyde were different during the daytime and nighttime. This method proved suitable for the routine operation and may provide additional insight on sources and sinks of atmospheric formaldehyde.     

A metal nebulizer capillary electrophoresis/Fourier transform infrared spectrometric interface

A capillary electrophoretic (CE) system has been successfully interfaced to a Fourier transform infrared spectrometer. The advantage of such an interface is that analytes may be detected and often unequivocally identified without analyte derivatization. The interface consists of a stainless steel tube in which the CE capillary is placed and the two are held in contact with the use of a metal tee. A solvent elimination approach is used with the interface, so that analytes are deposited onto an infrared transparent window, that is, CaF2, and measured with the use of an infrared microscope. A critical component of this design is to provide an electrical connection at the end of the CE column to permit stable separations that allow for efficient transport of the sample onto the window. The interface produces an aerosol that is directed at the surface of the infrared transparent window. The use of a volatile electrolyte, along with the flow of helium, allows for partial evaporation of the electrolyte in flight and complete evaporation of the solvent and electrolyte on the surface of the window to produce a "dry", or neat, analyte deposit.     

On-line preconcentration prior to on-column derivatization monolith octadecasiloxane capillary electrochromatography for the determination of biogenic amines

To expand the applications of the on-line preconcentration technique with capillary electrochromatography (CEC) to biogenic amines that have no specific chromophore or fluorophore in their molecules, a method of on-line preconcentration prior to on-column derivatization CEC is presented. A monolithic ODS capillary column (20 cm effective length x 75 microm i.d.) for CEC was fabricated using a thermal sol-gel reaction of tetraethyl orthosilicate to capture ODS particles (5-microm particle diameter) in a capillary tube. A standard model biogenic amine solution consisting of histamine, methylhistamine, and serotonin was electrokinetically injected from the anodic site of the capillary column with 5 kV, and these amines were effectively concentrated at the inlet site of the capillary column by a field-amplified sample stacking, a gradient effect mode, or both. This preconcentration occurred whenever the several types of solvent for reconstitution of the amines, e.g., water (noneluting solvent or low-conductivity solvent), 0.9% sodium chloride (noneluting solvent or high-conductivity solvent), or 60% acetonitrile in 10 mM borate buffer (pH 10) (eluting solvent) were employed. After concentration, the amines were subsequently derivatized, separated, and detected during CEC with an optimum CEC run buffer solution containing 60% acetonitrile in 5 mM o-phthalaldehyde/2-mercaptoethanol-10 mM borate buffer (pH 10) when 5 kV was continuously applied. Using the present system, equipped with a fluorescence detector instead of a UV/visible detector, the detection sensitivity for amines reached a 0.1 microM level, which increased sensitivity by a factor of 10(3) times greater than that of normal on-column derivatization CEC.     

Speciation of alkyllead and inorganic lead by derivatization with deuterium-labeled sodium tetraethylborate and SPME-GC/MS

A method for full speciation and determination of alkyllead and inorganic lead(II) in aqueous samples was developed. This was accomplished by in situ derivatization with deuterium-labeled sodium tetraethylborate NaB(C2D5)4 (DSTEB). The derivatization was carried out directly in the aqueous sample and the derivatives were extracted from the headspace by a solid-phase microextraction (SPME) fiber. The extracted analytes were then transferred to a GC/MS or a GC/FID for separation and detection. The research presented demonstrates that SPME and the derivatization reagent DSTEB can be used successfully for the speciation of Pb2+, Pb(CH3)3+, Pb(C2H5)3+, and Pb(C2H5)4 in water samples. All derivatives, Pb(C2D5)4, (CH3)3Pb(C2D5), (C2H5)3Pb(C2D5), and Pb(C2H5)4, are separated using an SBP-5 column. This method was applied to monitor degradation of tetraethyllead in water. This is the first report of ethylation by DSTEB for full speciation of methyllead, ethyllead, and inorganic lead compounds. This approach can be extended to other organometallic compounds as demonstrated for ethyltin speciation. This full speciation method will aid in monitoring occurrence, pathways, toxicity, and biological effects of these compounds in the environment. It is easily adopted for field analysis.     

Pervaporation as an alternative to headspace

The use of pervaporation as an alternative to headspace is proposed. The analytical system involves the speciation of organomercury compounds in solid samples using pervaporation, which has been coupled for the first time to gas chromatography. The speciation of mercury as Me(2)Hg, Et(2)Hg, and MeHgCl has been carried out without any derivatization of the analytes, which, after separation from the solid matrix, are preconcentrated on a Tenax minicolumn prior to desorption and chromatographic separation on a semicapillary column (HP-1) prior to atomic fluorescence detection. No column degradation was observed. Linear ranges and detection limits slightly better than those obtained by headspace GC were observed for mercury species in solid samples. Excellent recoveries (between 95 and 107%) for mercury species added to complex solid samples were obtained by this extremely simple and easily automated setup.     

LC-MS analysis of carbonyl compounds and their occurrence in diesel emissions

Liquid chromatography coupled with atmospheric pressure chemical ionization (APCI) ion trap mass spectrometry (ITMS) is applied to atmospheric aerosol relevant carbonyls. Characterization of positive and negative ion detection mass spectra are presented for 24 model compounds analyzed in their underivatized and O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine (PFBHA) oxime forms. The addition of PFBHA derivatization enhanced the detection and sensitivity for many of the carbonyls investigated. For all but five of the carbonyls examined, a pseudomolecular (M + H)+ ion is the base peak in the APCI positive ion mass spectra of PFBHA oxime derivatives and is observed in four of the five exceptions. Application of the evaluated analysis methodology to heavy-duty diesel source emissions facilitated the quantification of 10 aliphatic carbonyls (5 C5-C9 ketones, 4 C6 unsaturated ketones, 1 C6 dicarbonyl) and 14 aromatic carbonyls (1 C9 aldehyde, 5 C8-C13 ketones, 8 C6-C14 quinones). Diesel truck engine emission factors spanning 0.55-540 microg km(-1) were measured for gas- and particle-phase carbonyls. Good agreement was observed for gas-phase emission factors with results obtained by gas chromatography with ITMS.     

高效液相色谱柱前衍生荧光检测法测定游离脂肪醇

本文利用新型荧光试剂1,2-苯并-3,4-二氢咔唑-9-乙酸(BCAA)作为柱前衍生试剂建立了测定游离脂肪醇的方法,实验以1-乙基-3-(3-二甲氨基丙基)环己碳二亚胺(EDAC)作为缩合剂,4-二甲氨基吡啶(DMAP)为催化剂,55℃下衍生反应25min后获得稳定的荧光产物。在Eclipse XDB-C8色谱柱上,通过梯度洗脱对12种游离脂肪醇进行了分离和在线质谱定性。采用大气压化学电离源(APCI)正离子模式,对抗静电剂(十二烷基磷酸酯钾盐)中游离脂肪醇进行定性及相应含量测定。脂肪醇的线性回归系数大于0.9997,检测限在9.40-25.32fmol。     

Electrogenerated chemiluminescence detection of amino acids based on precolumn derivatization coupled with capillary electrophoresis separation

A novel method for highly sensitive detection of primary and secondary amino acids with selective derivatization using acetaldehyde as a new derivatization reagent was proposed by capillary electrophoresis (CE) coupled with electrogenerated chemiluminescence (ECL) of tris(2,2'-bipyridine)ruthenium(II). The precolumn derivatization of these amino acids with acetaldehyde was performed in aqueous solution at room temperature for 1 h. Upon optimized derivatization, the ECL intensities and detection sensitivities of the amino acids were significantly enhanced by 20-70 times. Using four amino acids, arginine, proline, valine, and leucine, as model compounds, their derivatives could be completely separated by CE and sensitively detected by ECL within 22 min. The linear ranges were 0.5-100 microM for arginine and proline and 5-1000 microM for valine and leucine with the detection limits of 1 x 10(-7) (0.5 fmol, arginine), 8 x 10(-8) (0.4 fmol, proline), 1 x 10(-6) (5 fmol, valine), and 1.6 x 10(-6) M (8 fmol, leucine) at a signal-to-noise ratio of 3. The derivatization reactions and ECL process of amino acids were also proposed based on in situ Fourier transform infrared and ultraviolet spectrometric analyses.     

高效液相色谱法测定家用装饰材料中甲醛、乙醛的含量

考察了甲醛、乙醛、2,4-二硝基苯肼的最佳衍生化条件,建立了高效液相色谱法同时测定内墙涂料中的甲醛、乙醛含量的方法。选用EclipseXDB-C18色谱柱(150mm×4.6mmi.d,5μm),以甲醇-水溶液(80:20,v/v)作为流动相进行洗脱,利用二极管阵列检测器,检测波长350nm。该方法具有较好的重现性和线性关系,相关系数均达到0.995以上,加标回收率分别为93.7%和95.9%,检测限分别为2.5×10-4mg·L-1和2.2×10-4mg·L-1。该方法简便、准确、灵敏度高。     

Enrichment of carbonylated peptides using Girard P reagent and strong cation exchange chromatography

It has been shown that oxidatively modified forms of proteins accumulate during oxidative stress, aging, and in some age-related diseases. One of the unique features of protein oxidation by a wide variety of routes is the generation of carbonyl groups. Of major interest in the study of oxidative stress diseases is which proteins in a proteome are being oxidized and the site(s) of oxidation. Based on the fact that proteins are generally characterized through tryptic peptide fragments, this paper reports a method for the isolation of oxidized peptides, which involves (1) derivatization of oxidized proteins with Girard P reagent (GRP; 1-(2-hydrazino-2-oxoethyl)pyridinium chloride), (2) following proteolysis enrichment of the derivatized peptide using strong cation exchange (SCX) chromatography, and (3) identification of oxidation sites using tandem mass spectrometry. Derivatization of aldehydes and ketones in oxidized proteins was accomplished by reacting protein carbonyls with the hydrazide of GRP. The resulting hydrazone bond was reduced by sodium cyanoborohydride to further stabilize the labeling. Derivatization time and concentrations of the derivatizing agent were optimized with model peptides. Oxidized transferrin was used as model protein to study derivatization efficiency at the protein level. Following metal-catalyzed oxidation of transferrin, the protein was derivatized with GRP and trypsin digested. Positively charged peptides were then selected from the digest with SCX chromatography at pH 6.0. Seven GRP-derivatized peptides were found to be selected from transferrin by MALDI-TOF-TOF analysis. Fourteen underivatized native peptides were also captured by the SCX column at pH 6.0. Mapping of the derivatized peptides onto the primary structure of transferrin indicated that the oxidation sites were all on solvent-accessible regions at the protein surface. Efficiency of the method was further demonstrated in the identification of oxidized proteins from yeast.     

Characteristics and health impacts of VOCs and carbonyls associated with residential cooking activities in Hong Kong

Cooking emission samples collected in two residential kitchens were compared where towngas (denoted as dwelling A) and liquefied petroleum gas (LPG) (denoted as dwelling B) were used as cooking fuels. A total of 50 different volatile organic compounds (VOCs) were quantified during the 90 min cooking periods. None of any carcinogenic compounds like formaldehyde, acetaldehyde or benzene are detected in the raw fuels, confirming that those are almost entirely derived due to cooking activity alone. Alkenes accounted for approximately 53% of the total measured VOCs collected at dwelling A, while alkanes contributed approximately 95% of the VOCs at dwelling B during the cooking periods. The concentration of aromatic hydrocarbons such as benzene and toluene also increased during the cooking periods. The total amount of carbonyls emitted from the cooking processes at dwelling A (2708 μg) is three times higher than that at dwelling B (793 μg). Acetaldehyde was the most abundant carbonyl at the dwelling A but its emission was insignificant at the dwelling B. Carcinogenic risks on chronic exposure to formaldehyde, acetaldehyde, and benzene for housewives and domestic helpers were evaluated. Formaldehyde accounts for 68% and close to 100% of lifetime cancer risks at dwelling A and B, respectively.     

Sampling and analysis of airborne particulate matter and aerosols using in-needle trap and SPME fiber devices

A needle trap device (NTD) and commercial poly(dimethylsiloxane) (PDMS) 7-microm film thickness solid-phase microextraction (SPME) fibers were used for the sampling and analysis of aerosols and airborne particulate matter (PM) from an inhaler-administered drug, spray insect repellant, and tailpipe diesel exhaust. The NTD consisted of a 0.53-mm o.d. stainless steel needle having 5 mm of quartz wool packing section near the needle tip. Samples were collected by drawing air across the NTD with a Luertip syringe or via direct exposure of the SPME fiber. The mass loading of PM was varied by adjusting the volume of air pulled through the NTD or by varying the sampling time for the SPME fiber. The air volumes ranged from 0.1 to 50 mL, and sampling times varied from 10 s to 16 min. Particulates were either trapped on the needle packing or sorbed onto the SPME fiber. The devices were introduced to a chromatograph/mass spectrometer (GC/MS) injector for 5 min desorption. In the case of the NTD, 10 microL of clean air was delivered by a gas-tight syringe to aid the introduction of desorbed analytes. The compounds sorbed onto particles extracted by the SPME fiber or trapped in the needle device were desorbed in the injector and no carry-over was observed. Both devices performed well in extracting airborne polycyclic aromatic hydrocarbons (PAHs) in diesel exhaust, triamcinolone acetonide in a dose of asthma drug and DEET in a dose of insect repellant spray. Results suggest that the NTDs and PDMS 7-microm fibers can be used for airborne particulate sampling and analysis, providing a simple, fast, reusable, and cost-effective screening tool. The advantage of the SPME fiber is the open-bed geometry allowing spectroscopic investigations of particulates; for example, with Raman microspectroscopy.