Application of 2-D gas chromatography for environmental analysis
The usual one-dimensional gas chromatography (1D-GC) compared to a all two-dimensional gas chromatography (GC?GC) which caters the superfluous deal-outs, reformd conversion and multifarious of sensitivity. Additionally, it was compose two-dimensional construct chromatogram, which is the evidence of help in the composite arrange. Samples can recurrently be minimized or equal elucidated in some contingencys for the experience, as technology caters excusable disunion faculty. All these blessings construct GC?GC in the toxic amalgamations complicated in the favor of track smooth environmental disengagement of a very good-tempered-tempered-natured-natured cat's-paw in involved matrices. This tract summarizes some of the environmental disengagement and criticism and monitoring of the GC?GC collisions
Many years of anthropologicals fellowship harvest led to multifarious of the universe arrangement of chemicals in the sky, the Earth’s demeanor and plant verge. Multifarious of these amalgamations are disadvantageous to the universe’s ecosystems and the persons. Disengagement of these amalgamations in the environment is weighty. When analytes enjoy lofty exhalation influence, gas chromatography is the valuable rule. The deep substance in the environmental disengagement is to dissect the entity of symbolical is usually very involved matrix track. Result, a immense examination pi into the disengagement of deep environmental pollutants .
Methods used in environmental disengagement is usually the resembling as in all aspects of experience. It embodys sampling, contingency making-ready, disunion and conflict. All of these marchs may blessing from substitute, it is usually the biggest wordations imposed by the disunion march. In gas chromatography (GC) contingencys, the deepity of environmental contingencys compriseing analyte and matrix elements of multifarious air-tight eluting peaks in a chromatographic size (1D) the apex aggregate deal-outs is exceedingly exceeded, and multifarious coelutions and unresolved in the disunion clime was observed. This led to the analyte of observation and quantify the thin disunion .
Poor conversion in the chromatographic disengagement of contingency making-ready and conflict of lofty ask-for for equipment reconsignment. Expensive and labor-intensive contingency making-ready, and unfoldnt attenuate may origin a lot of disadvantageous to the environment. By microparentage rule harvest, such as liquescent-liquescent microparentage (LLME) and hardy evidenceion microparentage (SPME) and non-dissolved contingency vestibule rule (ie, plain curiosity-behalfed desorption), has the implicit to exceedingly facilitate the contingency making-ready arrangement, extraneously sacrificing sensitivity and selectivity [2-5]. On examination, delaydrawal of conversion recurrently channel using magnitude spectrometry (MS), including lofty-conversion magnitude spectrometry (HRMS), in some contingencys, is requisite. Figure 1 illustrates the GC-MS encountered in the spiritless substances . In the disengagement of patronage selects spiritlessly 1D-GC clinch delay insecticides (Fig. 1b), track observation (in this contingency chlorfenvinphos) coelute analyte and contingency matrix is ??over general elements. Results obtained for such amalgamations, magnitude spectrometry (Figure 1e) constantly comprises amalgamations modeadmonish from fragments of interlocution, superfluous to thin matching and library magnitude spectrometry (Fig. 1d). MS overlap algorithm may exceedingly remould the rule of the knowledge of coeluting peak, but they are not frequently lucky, when the sum of coelutions is lofty. Figure 1a shows, generous 2D-GC (GC?GC) to extension extension and remould the chromatographic disunion of the conversion, piing in the disunion of analytes of observation (chlorfenvinphos) from coeluting amalgamations and matrix elements. Result, reformd the rule of the analyte magnitude (Fig. 1c), preamble into representation the evidence of a over bold disengagement of symbolical (Figure 1d). It is feasible that some coelutions exist; these may recurrently unfold efficiently overlap delay the MS, superfluous to amend pis, season reducing the sum of elements when the coeluting. GC?GC disunion delay the extensiond faculty piing in a lucky profession and quantification of analytes.
Fig. 1 GC?GC–TOF MS versus 1D-GC–TOF MS for the disengagement of a carrot select.
The superfluous-talents substance in stipulations of usual gas chromatography through multi-dimensional gas chromatography to compete (MDGC) implementation. In this rule, one-dimensional (1D) chromatogram of a involved and unresolved deal-out is subjected to the immovable evidenceion coated delay a coopeadmonish support disunion of the other selectivity . Although this rule extensions the 1D chromatographic deal-out of the valuable of chromatographic conversions, this rule delay automation challenging, and simply a few contingency elements can be adequately addressed. However, the multifarious collisions is good-tempered-tempered-natured-natured for the PCBs, pesticides and toxaphene disengagement, disordinary other things, the recital delay contrariant limits of luck [6-12]. Overall, still, is the just sum of disunion terminate be usageous, if the firm contingency is subjected to a disunion in two sizes. This became feasible a all two-dimensional gas chromatography (GC?GC) in the vestibule.
Principle for Two-Dimensional Gas Chromatography (GC?GC)
2D-GC is a all rule of indispensable discerption to as the superfluous deal-outs. A natural construct of GC?GC set in Figure 2. The basic construct of GC?GC using virtually is the resembling as the constituency of 1D-GC. These emcollectiveness syringes, oven, supports and enlighteners. In a natural GC?GC rule, using non-polar immovable evidenceion coated delay a condensed coating of a desire support was based as the deep support. The exports through a proper interface or modem is aaffect to the opening of the coopeadmonish size support coated delay immovable evidenceion of another selectivity. Modulator aaffect not simply to elementary and cooperateary support; its deep role is reordinary tackle of the copious recalcitrant from the excellentest size and interrupted introduction of them to the mould of contracted pulses disconnected into aid chromatographic disengagement. Beorigin the action of 2D-GC in the accelerated case, the enlightener in the GC?GC valuable is scant to those desirable of accelerated facts store admonish. For mould, GC?GC enlightener can emcollectiveness glisten ionization enlightener (FID), electron restrain enlightener (ECD), individual minute address enlightener (AED), sulfur amalgamations optical enlightener (SCD), nitrogen photoenlightener amalgamations (NCD) and duration of stampede magnitude spectrometer (TOF MS).
Fig. 2 A obstruct diagram of a GC?GC rule.
Modulator is the weighty deal-out of the channel, beorigin it answer-fors the disunion is all and multidimensional . In 1991, the excellentest implementation of the GC?GC, the scene has witnessed a sum of modulator project . Initially, the use of curiosity-behalfed structure of the ebullition modulator was implemented; still, the modular cryogenic liquescent (liquescent carbon dioxide or nitrogen) is ordinaryly the deep use. Modulator at low temperatures delayin the rule, each project has its own unconnected usages and wordations, making it appropriate for disengagement of the local mold. For mould, the disengagement of breathe-into pollutants has been patent clear an interface , when the buildings, and an in-house collisions modulator in the indispensable disengagement of PAHs and PCBs has been forcible . Then, the modulator of the contrariant molds of analyte in the disengagement of organohalogenated been evaluated .
The implementation of GC?GC caters the forthcoming usage to transcend the 1D disunion rule: reformment disunion force; reformd sensitivities; and constructs or loftyly predetermined, stratography spectrum. In the environment disengagement, GC?GC has the implicit to remould the toxic amalgamation through the disunion from the coeluting disengagement and the matrix element, extensions the conflict word such chemical pi and caters the chimerical for the surveillance collision the two-dimensional stratography spectrum which constructs. Finally, this maybe origins to subject to the meanest contingency making-ready progress, and subjects disengagement duration. Other collisions are to-boot feasible. For mould, of-late, GC?GC the pi honor which disconnected into for the diesel oil hydrocarbon environment had used, was weighty affected multifarious ecosystems  the oil speed.
Application of GC?GC in Environmental Analysis
Water and Residuum Analysis
The breathe-into is the most basic symbolical to the estate in planet. In prescribe to honor that the tap breathe-into protection for anthropological decrement, the flying, respectful and the accuadmonish rule needs to disengagement the breathe-into. The residuum is to-boot weighty for large stream and the lake; The disengagement of breathe-into pollutant is duration-consuming contingency making-ready, follows by GC-MS dissects. In the judicious season realized that GC?GC has the sublime implicit reformment to disengagement breathe-into and residuum.
In its primeval collisions in this clime, GC?GC was explained maybe from the spiritless matrix interlocution which is separating the BTEX (benzene, toluene, ethyl benzene and xylene) and methyl alcohol tert butyl ether (MTBE), when and SPME . The disunion force of GC?GC is reformd; MTBE and the benzene are the rudiments cord discerption in the 2nd chromatograph disengagement extension. This examination showed GC?GC has the sublime implicit for breathe-into pollutant disengagement by co-operation this technology delay microparentage (chief extension SPME).
Certain Earth’s freshbreathe-into collectiveness is defiled daily by petroleum and the oil defilement. In the 1970s, it is pays observation the petroleum contingency stratography spectrum to evidence a mould, has not unfoldd, rudiments cord which rises “hillock” . Chromatogram is the involved deal-out, including amalgamation multifarious contrariant peels, refers to “undiscerption involved structure” at inform . GC?GC-FID uses in disengagement of two contrariant freshbreathe-into residuums . Observed the usual contingency making-ready progress, the creator has used the remarkable conversion, and has fabricated the chromatogram of residuum for UCM contrariant smoothe by GC?GC. The chromatogram obtained for two contingencys caters by explication plainion defilement weighty origin examinationer. , The examination showed GC?GC the implicit weightyly in the environment law, for an environmental chemistry basic cat's-paw, environmental audit.
The nonylphenol polyethylene ethoxides’ degenerated pi, was feasible damely hormone splitter . Increases the subject, NPs from the polished confine  the breathe-into and the manifestation inform are fix. GC?GC-TOF MS is the NP isomer disunion from technical structure  used. 41 elements are attested. Figure 3 dilution GC?GC-TOF MS collision to NP isomer appertaining ion track disengagement from selfsame examination. Two NP forefend pis were explained that m/z 135 (chart 3a) and m/z 149 (chart 3b). Two chromatogram evidenceion bunch mold disunion, emphasizes by the union amalgamation peak apex esteem in the selfsame homologous parentage inccord cord. It from as a pi of contrariant NP isomer construct unifomity, the accomplished disunion is the very inexplicable this chart is patent. However, other conversion force by GC?GC granted “cleanly” the magnitude spectrum to cater, made the disengagement evidence to be easier.
Fig. 3. Extracted ion GC?GC–TOF MS chromatograms of a technical nonylphenyl (NP) structure
GC?GC for to the environment pollutant’s disengagement was of-late the collision ordinary in nautical deposit . A ascititious rule has patent clear, accelerated and is unified according to the i-aim by the ultrasonic triumph help’s adoption to the involved contingency’s lofty conversion disengagement caters to GC?GC-TOF UAE which is accelerated and lofty aptitude exceptive sampling pretreatment progress is utilized hardy contingency . A lofty aptitude and has the exceptive contingency making-ready rule, when the facultyful disunion rule GC?GC be-partial delay UAE can origins 1500 peel of over than divers not balmy hydrocarbon (PAHs) the amalgamation and the certificate conversion, NPs and dialkylated benzene. Once over, GC?GC not simply force from each other insularity disengagement, and has proven from the contingency matrix inestimable.
The carcinogen which and the mutagen reported, PAHs is multifarious perseverance earnestness by-pi and the exhaustive entity is exclusive in the environment. Beorigin it solicits the inexplicable sledding and has the exceptive contingency making-ready, they in the manifestation contingency’s track favor are inexplicable. The reformment to involved matrix’s PAHs, the Cavagnino track disengagement delay GC?GC-FID [large-volume splitless introduction (LVSI) technology]. Contingency involved which dissects is multifarious manifestation contingency delegated-to-others who obtains from the large stream and the lake. Disconnected and investigates sequal PAHs which apexless in the structure diesel oil to demonstadmonish the LVSI- GC?GC-FID implicit prosperity in the low ppb smooth for to track aggregate disengagement one facultyful and the flying cat's-paw in involved matrix PAHs.
While, Ong. and so on has patent clear a PAHs flying surveillance rule probably in the begrime contingency, utilizes liquescent adoption (PLE) – GC?GC-FID . The ordinary publishing pi is narrowly GC?GC implicit useful profession to manifestation contingency PAH disengagement. In illiberal, delay the conversion which reforms, reformment multifarious sensitivities and the stratography spectrum which prescribes, GC?GC may add on the pi which potent and the flying contingency making-ready rule produces cannot be terminated by the uniformity disengagement progress.
Analysis of PCBs, PCDDs and PCDFs
Polychlorinated dibenzodioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and some polychlorinated biphenyl (PCB) congeners is dominated by bioaccumulation and biomagnification in the environment and thus is a hazardous The wildestate and persons. Multifarious are reported carcinogens and quantitative substitutes of . Of PCBs, dioxins and furans in the environment toll of incontrovertible requirements of a rule to disunited and quantify them in involved contingencys such as patronage, begrime and breathe-into.
GC?GC caters one usageous rule in involved matrix’s PCDDs and the PCDFs disengagement. In its one of forthcoming experiments, a liquescent crystal deep support and a wordless cooperateary support (according to fume influence disunion) uses in (according to the planarity disunion) disuniteds the pitch – and from technical structure  non-straight PCB congeners. The union GC?GC microelectron restrains investigates (MECD) is toxic PCBs, PCDDs and the PCDFs favor is the collision in the cod liver contingency . The disengagement pi showed all 12 initiative PCB from liver contingency congeners, and most toxic Dai Aoxin and fu nan the generous disunion and the evidence nail accelerated delay 90 PCBs and 17 comprise vitiate PCDDs and PCDFs. Moreover, when compares delay the test contingency making-ready progress, the liver contingency pretreatment does not enjoy the selectivity and subjects to is meanest. It has embodyd the plain introduction and fractionation followed cell limit of complaint spiritual draws tail, the centrifuge arrangement to invade GC?GC the rule. Figure 4 showing from the 2nd stratography spectrum which obtains to the cod liver contingency’s disengagement. Recently, an ace of multilaboratory examination has been conducted in patronage contingency, dissects PCDD/Fs and Universe Bloom Construction PCBs through once over GC?GC-MECD and the GC-HRMS comparison and the dilution GC?GC sublime implicit in the flying surveillance collision .
With the test disengagement rule comparison GC?GC, GC?GC the work is unified (GC?GC-ID-TOF MS) has to 13C thread isotopic infirmity (ID) TOF MS usual GC-HRMS to survey . Quantification 17 PCDD/Fs and lewd PCBs nail accelerated in the begrime and in the manifestation contingency are two rules are resembling. However, GC?GC implementation solicit simply meanest contingency making-ready, and origins the memorable reformment (constituent 5-10), remarkable conversion, inferior channelation charge, and reformd TOF the MS facts  the spirit overlaps legitimately. As superfluous deal-outs which and conversion pi extensions, the mysterious amalgamation’s evidence is feasible.
Fig. 4 GC?GC–ECD chromatogram of a cod liver contingency spiked delay 90 PCBs .
Forms the summon to the pesticide disengagement to dissect the chemist to order encircling the contingency to construct the law and the chromatography. Is resembling other toxic amalgamation, the pesticide is usually exclusive in the track aggregate environment. Moreover, they are utmost involved matrix deal-out of for mould patronages, the begrime and the breathe-into contingency. Needs to be affect today presses to the flying lofty conversion disengagement rule.
GC?GC the collision forthcoming showed the rule implicit ordinary implementation to the pesticide disengagement in person’s construction in the coming. Supercritical perpetual adoption (SFE) delay GC?GC-FID unitedly utilizes the disengagement in person’s rank serum  the pesticide. To were few from the acute person’s rank serum adoption’s 15 pesticide’s rudiments cord segments terminate in lewd minutes. Later, GC?GC-FID to honor that the slip pesticide charybdis has been utilized through the use urine and the rank serum  low-power. This proper mould in were few showed 16 pesticide accomplished disunions in lewd minutes. Recently, has been presentd including PCBs and the constitutional chlorine pesticide 59 construction pollutant’s evidence and the quantification . But GC?GC-ID-TOF MS accomplishedd the resembling pi creator who ran in test uniformity disengagement (GC-ID-TOFMS) to declare that dissectd affect this, three contrariant introduction needs. GC?GC the collision forthcoming showed the rule implicit ordinary implementation to the pesticide disengagement in person’s construction in the coming. Supercritical perpetual adoption (SFE) delay GC?GC-FID unitedly utilizes the disengagement in person’s rank serum .
Pesticide favor in patronage select is resemblingly weighty. Disconnected using GC?GC-TOF MS and identifies 58 pesticides to nail accelerated accomplishedly on the vegetable was explained . This accomplishedd delay has been meanest and the non-exceptive contingency making-ready: The celery or the carrot contingency and the sodium acetate and the ethyl acetate enjoy chopped, partial, was partial, has been disconnected, and is dried. The select is injected invadeed GC?GC .
Recently, disconnected 12 halogenate amalgamation peel of bunchs five contrariant GC?GC support co-operation to survey, including PCBs, PCDDs, PCDFs, multi-chlorobenzene diphenyl ester (PCDEs), multi-chlorobenzene naphthalene (PCNs), multi-chlorobenzene dibenzothiophenes (PCDTs), multi-chlorobenzene terphenyl (PCTs), multi-chlorobenzene alkane (PCAs), toxaphene, multi-bromination biphenyl (PBBs), multi-bromination diphenyl ether (PBDEs) and constitutional chlorine pesticide (OCPs) . Although this expression focal apex is the contrariant amalgamation peel of deep bunch disuniteds, was to-boot explained in the parentage disunion. When the disunion and evidence all 28 OCPs are absolute pesticide structure has simply been presentd that deepity has been disconnected generousy, since, when injects adesire other 11 amalgamation peel of . Therefore, its as if that the support community which disposes well delay one, GC?GC may use takes deeply shields march for the environment contingency defilement and adesire pollutant multifarious other peel of pesticides, delay meanest contingency making-ready.
Volatile constitutional amalgamation (VOCs) in capital photochemical smog  the stock plays a hardy class. The Universe Bloom Construction idea that maybe has to the air granular symbolical’s dilution to the anthropological bloom  the ill pi. But, vicissitude entity encircling from VOCs bloom pi in capital granular symbolical (PM) . Therefore, solicits flying, true and knowledge rule answer-for in air pollutant lucky surveillance, evidence and breach.
Many PAHs and PAHs (oxy-PAHs) which oxidizes is the carcinogen which and the mutagen reported, delay, consequently they are in the capital aerosol disengagement productive target disengagement. GC?GC-FID and GC?GC lewd-pole MS (QMS) is applied permits from Finplant encircling 1500 peaks appearance PAHs  investigates in the capital air contingency and the evidence. But dame is unified the rule for the amalgamation evidence and the quantification, used GC?GC-FID the co-operation to perpetuate the good-tempered-tempered-natured-natured reproducibility. 13 non-appearance PAHs has been attested, and ten appearance PAHs by quota. Fix PAH centralism scompete (0.5-5.5 ng/m3) delay in Europe  other deal-outs of test rules obtained the pi was resembling.
The cigarette steam is honor utmost involved structure element  which has not orderly including encircling 4,700 peel of identification’s amalgamation and 100,000. GC?GC-TOFMS utilizes the discerption closely from the cigarette steam  30,000 peaks. After this, dissects cigarette steam condensate simpler contingency favor indifference reckoning , basic reckoning  and acidic reckoning  chemical constituency. Usual GC-MS feasible to sepaadmonish 200 mysterious peaks and identifies 115 hydrocarbons from the cigarette condensate wordless inunanalogous reckonings; To selfsame contingency GC?GC disengagement, still, has terminated 4,000 peel of amalgamation disunions and 1,800 hydrocarbons  proved. In another examination, GC?GC-TOF has attested 377 peel of nitrogen-containing amalgamation to the cigarette condensate’s basic reckoning’s MS disengagement, in 155 is the pyridine derivative, 104 peels kui lin or contrariant kui lin derivative and 56 peel of pyrazine derivative .
GC?GC has terminated the case flyingly for to the capricious constitutional amalgamation disengagement most facultyful cat's-paw. It appoints oneself prosperity to be appropriate accomplishedly for in the involved contingency surveillance disengagement technology. In the environment dissectd area, this embodys PCBs by the disengagement multifarious mould witness to the spiritless environment pollutant, PCDDs, PCDFs, PAHs and the pesticide in the involved environment matrix. Moreover, GC?GC has the implicit to facilitate the contingency making-ready progress (equal accomplishedly to elucidate them), when contemporaneously origins when the shorter overall disengagement duration lofty conversion stratography spectrum.
Regarding widely a new disengagement rule which adopts, not simply it is incontrovertiblely true and renewable, but it should to-boot evidence the indicative usage to transcend the rule which accepts. The mould recitaled the showing GC?GC rule usage in this criticism in the unwritten 1DGC disunion. In GC?GC unromantic excellentest years season, the channelation harvest is the deep focal apex; However, from GC?GC rule’s commercialization, the collision size which recitaled exceedingly extensions in the environment disengagement and other or-laws scenes. Therefore, we may prejudge that the transition automation GC?GC is unified on-cord contingency which the agreement uses to order spiritual the equipment in the ordinary environmental monitoring.
1. Marriott PJ. Haglund P, Ong RCY. Clin Chim Acta. 2003, 328:1–19.
2. Pawliszyn J. Hardy evidenceion microextraction, system and experience. Wiley, New York. 1997.
3. Pawliszyn J. (1999) Applications of hardy evidenceion microextraction. Royal Fellowship of Chemistry, Cambridge.
4. Dettmer K, Engewald W. Anal Bioanal Chem. 2002, 373: 490–500.
5. Butrym E. LC-GC. 1999, 17:S19–S24.
6. de Geus H-J, Wester PG, Schelvis A, de Boer J, Brinkman UATh. J Environ Monit. 2000, 2:503–511.
7. Mrowetz SHJ. J Chromatogr A. 1983, 279:173–187.
8. Duinker JC, Schultz DE, Petrick G. Mar Pollut Bull. 1998, 19:19–25.
9. Storr-Hansen E. Int J Environ Anal Chem.1991, 43:253–266.
10. Silvis LD, Kapila S, Yan Q, Elseewi AA. J Chromatogr A.1994, 688:221–230.
11. Schurig V, Reich S. Chirality. 1998, 10:425–429.
12. Liem DAK. Trends Anal Chem. 1999, 18:499–507.
13. Giddings JC. Anal Chem. 1984, 6:1258A–1270A.
14. Liu Z, Phillips JB. J Chromatogr Sci.1991, 29:227–231.
15. Hyotylainen T, Kallio M, Hartonen K, Jussila M, Palonen S, Riekkola M-L. Anal Chem. 2002, 74:4441–4446.
16. Kristenson EM, Korytar P, Danielsson C, Kallio M, Brandt M, Makela J, Vreuls RJJ, Beens J, Brinkman UATh. J Chromatogr A. 2003, 1019:65–77.
17. Arey JS, Nelson RK, Xu L, Reddy CM. Anal Chem. 2005, 77:7172–7182.
18. Gaines RB, Ledford EB, Stuart JD. J Microcol Sep. 1998, 10:597–604.
19. Beens J, Dalluge J, Adahchour M, Vreuls JJR, Brinkman UATh. J Microcol Sep. 2001, 13:134–140.
20. Blumer M, Souza G, Sass J. Mar Biol. 1970, 5:195–202.
21. Frysinger GS, Gaines RB, Xu L, Reddy CM. Environ Sci Technol. 2003, 37:653–1662.
22. Mueller SO. Anal Bioanal Chem. 2004, 378:582–587.
23. Ieda T, Horii Y, Petrick G, Yamashita N, Ochiai N, Kannan K. Environ Sci Technol. 2005, 39:7202–7207.
24. Moeder M, Martin C, Schlosser D, Harynuk J, Gorecki T. J Chromatogr A. 2006, 1107:233–239.
25. Morales-Munoz S, Vreuls RJJ, Luque de Castro MD. J Chromatogr A. 2005, 1086:122–127.
26. Cavagnino D, Magni P, Zilioli G, Trestianu S. J Chromatogr A. 2003, 1019:211–220.
27. Ong R, Lundstedt S, Haglund P, Marriott P. J Chromatogr A. 2003, 1019:221–232.
28. Schwarzenbach RP, Gschwend PM, Imboden DM. Environmental constitutional chemistry, 2nd edn. Wiley-Interscience, Hoboken, NJ. 2003.
29. Korytar P, Leonards PEG, de Boer J, Brinkman UATh. J Chromatogr A. 2002, 958:203–218.
30. Haglund P, Harju M, Ong R, Marriott P. J Microcol Sep. 2001, 13:306–311.
31. Danielsson C, Wiberg K, Korytar P, Bergek S, Brinkman UATh, Haglund P. J Chromatogr A. 2005, 1086:61–70.
32. Focant J-F, Reiner EJ, MacPherson K, Kolic T, Sjodin A, Patterson DG Jr, Reese SL, Dorman FL, Cochran J. Talanta. 2004, 63:1231–1240.
33. Liu Z, Sirimanne SR, Patterson DG Jr, Needham LL. Anal Chem. 1994, 66:3086–3092.
34. Dimandja J-M, Grainger J, Patterson DG Jr, Turner WE, Needham LL. J Exp Anal Environ Epidem. 2000, 10:761–768.
35. Focant J-F, Sjodin A, Turner WE, Patterson DG Jr. Anal Chem. 2004, 76:6313–6320.
36. Dalluge J, van Rijn M, Beens J, Vreuls RJJ, Brinkman UATh. J Chromatogr A. 2002, 965:207–217.
37. Korytar P, Leonards PEG, de Boer J, Brinkman UATh. J Chromatogr A. 2005, 1086:29–44.
38. Fowler D, Coyle M, Ashover MR, Bower J, Williams ML, Smith R, Dollard GJ, Lee DS, Jenkin M, Stedman JR, Cox RA, Derwent RG, Harrison RM, Hewitt CN, Maynard RL, Penkett SA, Weston KJ, Woods PJ, Burgess RA, Anderson R. Fourth Recital of the Oxidants Criticism Bunch 75-104. UK Department of the Environment, Transport and Regions, London. 1997.
39. WHO. Bloom aspects of air taint delay deal-outiculate subject, ozone and nitrogen dioxide. Universe Bloom Organization, Bonn. 2003.
40. Welthagen W, Schnelle-Kreis J, Zimmermann R. J Chromatogr A. 2003, 1019:233–249.
41. Kallio M, Hyotilainen T, Lehtonen M, Jussila ML, Hartonen K, Shimmo M, Riekkola M-L. J Chromatogr A. 2003, 1019:251– 260.
42. Schnelle-Kreis J, Welthagen W, Sklorz M, Zimmermann R. J Sep Sci. 2005, 28:1648–1657.
43. Dalluge J, van Stee LLP, Xu X, Williams J, Beens J, Vreuls RJJ, Brinkman UATh. J Chromatogr A.2002, 974:169–184.
44. Lu X, Zhao M, Kong H, Cai J, Wu J, Wu M, Hua R, Liu J, Xu G. J Chromatogr A. 2004, 1043:265–273.
45. Lu X, Zhao M, Cai J, Kong H, Wu J, Wu M, Hua R, Liu J, Xu G. J Sep Sci. 2004, 27:101–109.
46. Lu X, Cai J, Zhao M, Kong H, Wu J, Wu M, Hua R, Liu J, Xu G. Anal Chem. 2004, 74:4441–4451.