Chemical Hazards in the Workplace - American Chemical Society

22 Gas Chromatography-Mass Spectrometric Characterization of Polynuclear Aromatic Hydrocarbons in Particulate Diesel Emissions

Downloaded by NORTH CAROLINA STATE UNIV on January 7, 2013 | http://pubs.acs.org Publication Date: April 2, 1981 | doi: 10.1021/bk-1981-0149.ch022

DILIP R. CHOUDHURY and BRIAN BUSH Division of Laboratories and Research, New York State Department of Health, Albany, NY 12201

Polynuclear aromatic hydrocarbons (PAH), of widespread occurrence in the environment, result from incomplete combustion of carbon- and hydrogen-containing substances. Many PAHs are well-recognized carcinogens and mutagens. Several industrial processes, such as fossil fuel conversion and production of aluminium and ferroalloys, can produce PAHs and result in their occurence in the working environment. There is considerable current interest in development of state-of-the-art methodology for characterization of PAHs in various matrices (1). Gas chromatography and gas chromatographymass spectrometry are two techniques widely used for PAH analysis because the necessary equipment is available in most laboratories. The development of high resolution glass capillary columns has significantly advanced the compound-characterizing capability of these techniques. The major problem in PAH analysis is separation and conclusive identification of individual isomeric compounds, since the biological properties of many PAHs are isomer-specific. Another problem is the unavailability of many reference standards, making optimization of GC-operating parameters and column preparation methods for isomer separation difficult. The best possible s e p a r a t i o n e f f i c i e n c y i s c r u c i a l f o r i d e n t i f i c a t i o n and q u a n t i t a t i o n o f PAHs i n a n y e n v i r o n m e n t a l s a m p l e . I n a d d i t i o n , PAHs must be s e p a r a t e d f r o m o t h e r c l a s s e s o f compounds m o s t l y e n c o u n t e r e d i n environmental samples. D i e s e l emission p a r t i c u l a t e s , mostly of r e s p i r a b l e s i z e , are assuming i n c r e a s e d importance as a source o f a t m o s p h e r i c p a r t i c u late pollutants. T h e y may a l s o p r e s e n t s i g n i f i c a n t h a z a r d i n c e r t a i n w o r k i n g e n v i r o n m e n t s s u c h as b u s g a r a g e s a n d m i n e s . In t h i s paper a p p l i c a t i o n o f g l a s s c a p i l l a r y gas chromat o g r a p h y (GC) a l o n e a n d i n c o n j u n c t i o n w i t h mass s p e c t r o m e t r y

0097-6156/81/0149-0357$05.00/0 © 1981 American Chemical Society

In Chemical Hazards in the Workplace; Choudhary, G.; ACS Symposium Series; American Chemical Society: Washington, DC, 1981.

358

CHEMICAL HAZARDS IN THE WORKPLACE

(GC-M3) i s d e s c r i b e d f o r c h a r a c t e r i z a t i o n o f p a r t i c u l a t e - b o u n d PAHs i n d i e s e l e m i s s i o n s . The t e r m P A H w i l l r e f e r t o t h e p a r e n t and a l k y l - s u b s t i t u t e d PAHs. The a n a l y t i c a l m e t h o d o l o g y may a l s o be a d a p t a b l e t o o t h e r t y p e s o f sample m a t r i c e s . f

f


Experimental P r e p a r a t i o n o f t h e P a r t i c u l a t e E x t r a c t and I s o l a t i o n o f t h e PAH F r a c t i o n . D i e s e l e m i s s i o n p a r t i c u l a t e s were c o l l e c t e d b y d i l u t i o n t u n n e l t e c h n i q u e on P a l l f l e x T60A20 T e f l o n - c o a t e d g l a s s f i b e r f i l t e r s (20" χ 20") ( 2 ) . The p a r t i c u l a t e s were S o x h l e t e x t r a c t e d f r o m t h e f i l t e r s w i t h d i c h l o r o m e t h a n e f o r 2k h . After f i l t r a t i o n through a 0.2-um Fluoropore f i l t e r under p a r t i a l v a c u u m , t h e s o l v e n t was e v a p o r a t e d b y g e n t l e h e a t i n g u n d e r vacuum. S e v e r a l e x t r a c t s were p o o l e d t o p r o d u c e sample l a r g e enough f o r i n - d e p t h c h e m i c a l c h a r a c t e r i z a t i o n . Much o f t h e work d e s c r i b e d h e r e was p e r f o r m e d on t h e PAH f r a c t i o n s f r o m (a) SI, t h e p o o l e d p a r t i c u l a t e e x t r a c t f r o m a V o l k s w a g e n (VW) R a b b i t d r i v e n i n a h i g h w a y f u e l e f f i c i e n c y t e s t (HFET) m o d e , a n d (b) S 2 , the p o o l e d e x t r a c t from a Mercedes 300-D ( f e d e r a l t e s t procedure [FTP]). PAHs were i s o l a t e d f r o m t h e c r u d e e x t r a c t s b y a t w o - s t e p procedure. The n e u t r a l f r a c t i o n was s e p a r a t e d b y s i m p l e a c i d b a s e p a r t i t i o n i n g a n d t h e n c h r o m â t o g r a p h e d on a s i l i c a g e l c o l u m n . The c o l u m n was f i r s t e l u t e d w i t h TO m l o f h e x a n e . Subsequent e l u t i o n w i t h 200 m l o f h e x a n e c o n t a i n i n g 5% d i c h l o r o m e t h a n e g a v e t h e PAH f r a c t i o n . The s o l v e n t was c a r e f u l l y e v a p o r a t e d t o produce the d r y e x t r a c t . The PAH f r a c t i o n o f S I a n d S2 were d e s i g n a t e d a s S1-C2 a n d S 2 - C 2 , r e s p e c t i v e l y . GC and GC-MS A n a l y s e s . G l a s s c a p i l l a r y c o l u m n s were p r e p a r e d i n o u r l a b o r a t o r i e s a s d e s c r i b e d b r i e f l y e l s e w h e r e (3_). A l i q u o t s ( 1 - 2 u l ) o f t h e PAH f r a c t i o n d i s s o l v e d i n a s m a l l v o l u m e o f c h l o r o f o r m were i n j e c t e d w i t h o u t s t r e a m s p l i t t i n g i n t o t h e H e w l e t t P a c k a r d 58*+0A g a s c h r o m â t o g r a p h . I n j e c t i o n port temperat u r e was h e l d a t 2 5 0 ° C , and t h e c o l u m n oven t e m p e r a t u r e was s t a r t e d at 100°C. Two m i n u t e s a f t e r i n j e c t i o n a m u l t i s t e p t e m p e r a t u r e p r o g r a m was i n i t i a t e d ; f i n a l t e m p e r a t u r e was 290°C. N i t r o g e n was t h e c a r r i e r and make up g a s . Results

and D i s c u s s i o n

Chromatographic R e s o l u t i o n . To o p t i m i z e c o l u m n - c o a t i n g c o n d i t i o n s and o p e r a t i n g p a r a m e t e r s g l a s s c a p i l l a r y c o l u m n s c o a t e d w i t h v a r i o u s s i l i c o n e - b a s e d s t a t i o n a r y p h a s e s were t e s t e d w i t h d i f f i c u l t - t o - s e p a r a t e g r o u p s o f PAH s t a n d a r d s a n d Complex samples. The S E 5 ^ - c o a t e d c o l u m n s p e r f o r m e d e x c e l l e n t l y w i t h r e s p e c t t o s e p a r a t i o n e f f i c i e n c y , column b l e e d a n d l o n g - t e r m stability. O t h e r o b s e r v e r s have had s i m i l a r r e s u l t s w i t h t h i s


22.

CHOUDHURY AND BUSH

PAHs

in Diesel

Emissions

359


s t a t i o n a r y p h a s e (k). S i n c e many i s o m e r i c PAHs a r e e x p e c t e d t o occur i n environmental samples, i t i s e s s e n t i a l t o o b t a i n best p o s s i b l e chromatographic separation t o achieve c o n c l u s i v e i d e n t i f i c a t i o n and q u a n t i t a t i o n . A c h r o m â t o g r a m o f 21 s y n t h e t i c PAHs i s shown i n F i g u r e 1 . P e a k s were s h a r p a n d s e p a r a t i o n was e x c e l l e n t b e t w e e n b e n z o f a j a n t h r a c e n e and c h r y s e n e , b e n z o [ b ] f l u o r a n t h e n e and b e n z o [ k ] f l u o r a n t h e n e , and benzo[eJpyrene and b e n z o [ a ] p y r e n e . S e p a r a t i o n o f t h e s e t h r e e g r o u p s o f PAHs i s c r i t i c a l l y i m p o r t a n t , s i n c e some a r e m o d e r a t e t o s t r o n g c a r c i n o g e n s , w h e r e a s o t h e r s are r e l a t i v e l y innocuous. C a l c u l a t e d d e t e c t i o n l i m i t s o f low m o l e c u l a r w e i g h t PAHs were i n subnanogram t o l o w nanogram r a n g e , s l i g h t l y h i g h e r d e t e c t i o n l i m i t s were o b s e r v e d f o r h i g h - m o l e c u l a r ' w e i g h t compounds. I n o u r m e t h o d c o r o n e n e , a s e v e n - r i n g compound, e l u t e d i n hi m i n , as o p p o s e d t o 110 m i n r e p o r t e d e l s e w h e r e (hj. GC A n a l y s i s . T h e g a s c h r o m a t o g r a p h i c p r o f i l e o f t h e PAH f r a c t i o n S 1 - C 2 i s shown i n F i g u r e 2 A . A comparison of r e t e n t i o n t i m e s o f t h e m a j o r c o n s t i t u e n t s w i t h t h o s e o f p a r e n t PAHs showed t h a t 3 and h r i n g compounds p r e d o m i n a t e d . Readily identifiable p e a k s were p h e n a n t h r e n e ( p e a k l ) , a n t h r a c e n e ( p e a k 2 ) , 2 - p h e n y l n a p h t h a l e n e ( p e a k 7 ) , f l u o r a n t h e n e ( p e a k 11) a n d p y r e n e (peak 1 3 ) . M i n o r c o n s t i t u e n t s c o u l d n o t be i d e n t i f i e d w i t h a n y significant confidence. S e v e r a l abundant peaks between p h e n a n t h r e n e a n d f l u o r a n t h e n e were n o t r e a d i l y i d e n t i f i a b l e f r o m t h e i r retention times. The h i g h e r - m o l e c u l a r - w e i g h t PAHs were present i n r a t h e r low c o n c e n t r a t i o n . S i n c e many o f t h e s e a r e t o x i c o l o g i c a l l y s i g n i f i c a n t , t h e y were p r e c o n c e n t r a t e d f o r more definitive identification. A Z o r b a x - C N h i g h p e r f o r m a n c e l i q u i d c h r o m a t o g r a p h y (HPLC) column u s e d w i t h hexane as m o b i l e phase p r o d u c e d d e s i r a b l e results. D e t a i l s o f t h e HPLC p r o c e d u r e w i l l b e p u b l i s h e d e l s e w h e r e (5_). T h r e e HPLC s u b f r a c t i o n s o f S 1 - C 2 were m a d e : S 1 - C 2 A , S 1 - C 2 B , and S 1 - C 2 C . Gas c h r o m a t o g r a p h i c e x a m i n a t i o n o f e a c h s u b f r a c t i o n showed t h a t S 1 - C 2 C c o n t a i n e d t h e m i n o r constituents of interest, ( s e e t h e GC p r o f i l e , F i g u r e 2B a n d legend.). A l l o f t h e i m p o r t a n t i s o m e r i c compounds were separated. The PAH i s o l a t e f r o m s a m p l e S2 ( S 2 - C 2 , F i g u r e 3) showed a GC p r o f i l e s i m i l a r t o t h a t f o r S 1 - C 2 ( F i g u r e 2 A ) . T h e i r most a b u n d a n t components were s i m i l a r , and h i g h - m o l e c u l a r - w e i g h t PAHs were a p p a r e n t l y p r e s e n t i n l o w c o n c e n t r a t i o n o n l y . The r e c o r d e r a t t e n u a t i o n was c h a n g e d a t 19 m i n t o h e l p d e t e c t t h e l e s s abundant PAHs. E x a m i n a t i o n s of s e v e r a l o t h e r samples i n d i c a t e d similar patterns.



Figure J. Gas chromatogram of a mixture of PAH standards. GC conditions: 40-m χ 035-mm id SE54 glass capillary column; flame ionization detector; temperature 100°C for 2 min, programmed to 170°C at 10°/min, to 209° at 3°/min, to 265°C at 7°/min, to 290°C at 8°/min. Peak iden tities: 1, fluorene (3 ng); 2, phenanthrene (3 ng); 3, anthracene (6 ng); 4, 2-methylphenanthrene (6 ng); 5, 2-methylanthracene (6 ng); 6, 3,6-dimethylphenanthrene (6 ng); 7, fluoranthene (3.6 ng); 8, pyrene (6 ng); 9, benzolajfluorene (12 ng); 10, benzo[b]fluorene (12 ng); 11, benzo/aJanthracene (15 ng); 12, chrysene (12 ng); 13, benzo[b]fluoranthene (12 ng); 14, benzo[k]fluoranthene (12 ng); 15, benzo[e]pyrene (12 ng); 16, benzo [a]pyrene (8.1 ng); 17, perylene (12 ng); 18, dibe«z/a,h7anthracene (30 ng); 19, benzo[ghi]perylene (30 ng); 20, 1,2,3,4-dibenzopyrene (60 ng); 21, coronene (30 ng).

MINUTES



22.

CHOUDHURY AND BUSH

PAHs

in Diesel

Emissions

361

MINUTES

Figure 2. Gas chromatogram of A, PAH fraction of diesel particulate extract (SlC2) and B, its HPLC subfraction C (S1-C2). GC conditions: 45-m χ 0.35-mm id SE54 glass capillary column; flame ionization detector; temperature, 110°C for 2 min, programmed to 170°C at 10°/min, to 212°C at 3°/min, to 278°C at 8°/min. Peak identities: 1, phenanthrene; 2, anthracene; 3-6, methylanthracene/-phenan threne; 7, 2-phenylnaphthalene; 8-10, dimethylanthracene/-phenanthrene; 11, flu oranthene; 12, aceanthrylene/acephenanthrylene; 13, pyrene; 14-15, trimethylanthracene/-phenanthrene; 16, benzo [ghi] fluoranthene; 17, benzo [a] anthracene; 18, triphenylene; 19, chrysene; 20, benzo[b] fluoranthene; 21, benzo[\]fluoranthene; 22, benzo [k] fluoranthene; 23, benzo[e]pyrene; 24, benzo [a] pyrene.



Figure 3. Gas chromatogram of the PAH fraction S2-C2. GC conditions as in Figure 1. Peak identities: 1, phenanthrene; 2-5, methylanthracene/phenanthrene; 6, dimethyldibenzothiophene; 7, 2-pheny{naphthalene; 8-11, dimethylanthracene/phenanthrene; 12, fluoranthene; 13, pyrene; 1415, trimethylanthracene/phenanthrene; 16, benzo[ghi]fluoranthene; 17, benzo[a]anthracene; 18, triphenylene; 19, chrysene; 20, benzo[b]fluoranthene; 21, benzo[\]fluoranthene; 22, benzofk]fluoranthene; 23, benzo[e]pyrene; 24, benzo[a]pyrene.

MINUTES

20


22.

CHOUDHURY AND BUSH

363

PAHs in Diesel Emissions


GC-MS A n a l y s i s . PAHs p r o d u c e s t a b l e m o l e c u l a r i o n s u p o n e l e c t r o n impact; v e r y l i t t l e subsequent f r a g m e n t a t i o n t a k e s place. T h i s i s a d v a n t a g e o u s i n d e t e r m i n i n g m o l e c u l a r w e i g h t and h e n c e t h e e m p i r i c a l f o r m u l a and r i n g s y s t e m o f a PAH m o l e c u l e . H o w e v e r , l a c k o f f r a g m e n t a t i o n makes i t u s u a l l y i m p o s s i b l e t o d i f f e r e n t i a t e between s t r u c t u r a l i s o m e r s . Chromatographic separation is therefore essential for i d e n t i f i c a t i o n isomeric PAHs b y G C - M S . For d e f i n i t i v e c h a r a c t e r i z a t i o n of t h e G C - s e p a r a t e d c o n s t i t u e n t s , t h e t o t a l PAH i s o l a t e was e x a m i n e d b y GC-MS u s i n g t h e same c a p i l l a r y c o l u m n . Some l o s s o f c h r o m a t o g r a p h i c r e s o l u t i o n o c c u r e d i n t h e GC-MS w o r k , p r e s u m a b l y b e c a u s e t h e i n j e c t o r o f t h e Finnigan instrument i s s i g n i f i c a n t l y d i f f e r e n t from that of the Hewlett Packard gas chromatograph. The l o n g t r a n s f e r l i n e c o u l d be p a r t l y r e s p o n s i b l e t o o . O p e r a t i n g p a r a m e t e r s were s e p a r a t e l y o p t i m i z e d f o r t h e GC-MS w o r k . The t o t a l i o n c h r o m a t o g r a m o f t h e PAH f r a c t i o n S 1 - C 2 i s shown i n F i g u r e k. A t h o r o u g h s e a r c h o f t h e r e c o n s t r u c t e d i o n chromatogram ( R I C ) was made t o d e t e r m i n e t h e mass s p e c t r a o f a l l d e t e c t a b l e components. The s p e c t r a were compared w i t h t h o s e o f r e f e r e n c e s t a n d a r d s when a v a i l a b l e o r w i t h t h e s p e c t r a f r o m t h e mass spectral library. M o l e c u l a r w e i g h t s o f more a b u n d a n t c o n s t i t u e n t s a r e shown i n F i g u r e k many a d d i t i o n a l m i n o r components were a l s o characterized. A c o m p l e t e l i s t o f compounds c h a r a c t e r i z e d i n t h i s s a m p l e b y GC-MS i s g i v e n i n T a b l e I . 9

P h e n a n t h r e n e , f l u o r a n t h e n e , and p y r e n e — t h e t h r e e a b u n d a n t p a r e n t PAHs i d e n t i f i e d b y G C — w e r e c o n f i r m e d b y MS. The m a j o r GC p e a k s b e t w e e n p h e n a n t h r e n e and f l u o r a n t h e n e were c h a r a c t e r i z e d a s m e t h y l - and d i m e t h y l p h e n a n t h r e n e / a n t h r a c e n e . Four compounds, e a c h h a v i n g a n o m i n a l mass o f 1 9 2 amu were d e j e c t e d . Small fragment i o n s a t masses c o r r e s p o n d i n g t o ( M - l ) , ( M - 2 T ) and M ^ , were d e t e c t e d . A g e n e r a l f e a t u r e o f t h e s e s p e c t r a was l o s s o f a methyl group from the parent i o n . The s p e c t r a l f e a t u r e s a r e c h a r a c t e r i s t i c of dimethyl or ethylphenanthrene/anthracene. +

+

S i x compounds w i t h p a r e n t i o n s a t m/e 2 2 0 were d e t e c t e d . A l l s i x s p e c t r a showed s t r o n g f r a g m e n t i o n s a t m/e 2 0 5 c o r r e sponding to l o s s of a methyl group. The s p e c t r a l f e a t u r e s a r e i n g e n e r a l agreement w i t h t h o s e o f t r i m e t h y l o r m e t h y l e t h y l p h e n anthrene anthracene. E x a c t i s o m e r i c s t r u c t u r e s c o u l d not be d e t e r m i n e d b e c a u s e many i s o m e r s o f t h e m e t h y l - , C 2 - a l k y l - , a n d C ^ - a l k y l p h e n a n t h r e n e / a n t h r a c e n e a r e p o s s i b l e ; but o n l y a few m e t h y l p h e n a n t h r e n e / a n t h r a c e n e s t a n d a r d s were a v a i l a b l e t o u s . The p r e s e n c e o f c h r y s e n e , b e n z o [ a j a n t h r a c e n e , a n d t r i p h e n y l e n e was c o n f i r m e d . T h e s e t h r e e a p p e a r e d a s one b r o a d p e a k i n t h e RIC. H o w e v e r , t h e p r e s e n c e o f a l l t h r e e were e s t a b l i s h e d b y


364



Table

I

Compounds c h a r a c t e r i z e d

b y E I GC/MS o f

Scan No.

Compound

sample

S1-C2

539

Methylfluorene

609

Phenanthrene

6kk

Dimethylfluorene

656

Dimethylfluorene

670

Dimethylfluorene

680

Methyldibenzothiophene

703

Met h y I d i b e n ζ o t h i ophen e

721+

Met h y l p h e n a n t h r en e / - a n t h r a c en e

729

Met hy l p h e n a n t h r en e / - a n t h r a c en e

751

Methylphenanthrene/-anthracene

15k

Methylphenanthrene/-anthracene

7^5

C y c l o p e n t a [ d e f ] p h e n a n t h r en e

789

C2-Alkyldibenzothiophene

806

C^-Alkyldibenzothiophene

8lU

2-Phenylnapht halen e

830

C2~Alkylphenanthrene/-anthracene

841

C^-Alkyldibenzothiophene

853

C - A l k y l p h e n a n t h r e n e / - a n t h r a c ene

860

C2-Alkyldibenzothiophene

865

C2-Alkylphenanthrene/-anthracene

2


PAHs

CHOUDHURY AND BUSH

22.

Table


Scan

in Diesel

I

Emissions

(cont.)

Compound

885

C2- A l k y l p h e n a n t h r e n e / - a n t h r a c e n e

911

C - A l k y l p h e n a n t h r e n e / - a n t h r a c en e

9lé

Fluoranthene

2

9^5

Ac e p h e n a n t h r y 1 e n e / a c e a n t h r y 1 e n e

98Ο

Pyrene

1032

C ^ - A l k y l p h e n a n t h r en e / - a n t h r a c en e

lOUl

C3-Alkylphenanthrene/-anthracene

1057

C^-Alkylphenanthrene/-anthracene

106k

C^-AlkylphenanthreneZ-anthracene

1077

Methylpyrene/-fluoranthene

lllk

Benzo[aj f l u o r e n e

11^3

Benzo[b]fluorene

117^


llQh


13^+5

Benzo [ g h i ] f l u o r a n t h e n e

1353

Acepyrene

1U3U

Chrysene,

1724

Benzo[b l_,&k] f l u o r a n t h e n e

1775

Benzo [a] p y r e n e ,

benzo[aj anthracene,

triphenylene

9i

benzo[e]pyrene


365



366

SCAN 6 0 0 TIME 10.00 Figure 4.

800 13:20

1000 16-40

1200 20=00

1400 2320

1600 1800 26=40 3 0 Ό 0

2000 33 20

Total ion chromatogram of the PAH fraction S1-C2 (3), peak identities are listed in Table 1

Figure 5.

Total ion chromatogram of the PAH fraction S2-C2 (3)


22.

CHOUDHURY AND BUSH

PAHs

in Diesel

Emissions

367


t h e i r GC r e t e n t i o n t i m e s . T h e HPLC s u b f r a c t i o n S 1 - C 2 C e n r i c h e d w i t h h i g h - m o l e c u l a r - w e i g h t PAHs was n o t s e p a r a t e l y e x a m i n e d b y GC-MS. The p e a k w i t h t h e p a r e n t i o n o f m/e 226 was a s s i g n e d benzo[ghi]flucranthene. The r e f e r e n c e s t a n d a r d was n o t a v a i l a b l e , b u t i t s r e t e n t i o n i n d e x was i n a g r e e m e n t w i t h t h a t r e p o r t e d (389.6) b y L e e e t a l . (6_). The p r e s e n c e o f b e n z o [ b , j & k ] f l u o r a n t h e n e s was a l s o c o n f i r m e d . T h e y a p p e a r e d a s one b r o a d p e a k , b u t t h e p r e s e n c e o f a l l t h r e e was e s t a b l i s h e d b y t h e i r GC r e t e n t i o n t i m e i n t h e HPLC s u b f r a c t i o n S 1 - C 2 C . Benzo[ejpyrene a n d b e n z o [ a ] p y r e n e were a l s o c h a r a c t e r i z e d b y MS. PAHs w i t h h i g h e r r i n g s y s t e m s were n o t d e t e c t e d i n t h i s s a m p l e . Among m i n o r c o n s t i t u e n t s some 0 - a n d S - h e t e r o c y c l e s a n d t h e i r a l k y l d e r i v a t i v e s were d e t e c t e d . No n o n - P A H - t y p e compound o r p o l a r d e r i v a t i v e s o f PAHs ( e . g . , q u i n o n e s ) were d e t e c t e d i n t h i s f r a c t i o n b y mass s p e c t r o m e t r y i n d i c a t i n g t h e e f f e c t i v e n e s s of the i s o l a t i o n procedure. GC-MS e x a m i n a t i o n o f t h e PAH f r a c t i o n o f sample S2 ( S 2 - C 2 ) g a v e v e r y s i m i l a r r e s u l t s ; t h e t o t a l i o n c h r o m a t o g r a m i s shown i n F i g u r e 5. M a j o r c o n s t i t u e n t s were p h e n a n t h r e n e , f l u o r a n t h e n e , p y r e n e , and m e t h y l , d i m e t h y l / e t h y l p h e n a n t h r e n e / a n t h r a c e n e . R e l a t i v e a b u n d a n c e o f some C - a l k y l p h e n a n t h r e n e s / a n t h r a c e n e s were h i g h e r i n t h i s sample t h a n i n S 1 - C 2 . Smaller quantities of benzo[ghi]fluoranthene, chrysene, benzo[a]anthracene, triphenyl e n e , b e n z o [b , j _ , & k ] f l u o r a n t h e n e s , a n d b e n z o [ e & a j p y r e n e s and were c h a r a c t e r i z e d b y MS. I n a d d i t i o n , most compounds l i s t e d i n T a b l e 1 were a l s o d e t e c t e d i n t h i s s a m p l e . 2

Thus g l a s s c a p i l l a r y g a s c h r o m â t o g r a p h y - m a s s s p e c t r o m e t r y i s a p o w e r f u l t e c h n i q u e f o r d e t e c t i n g PAHs and d e t e r m i n i n g t h e i r r i n g system and e m p i r i c a l f o r m u l a . Use o f u l t r a - h i g h - r e s o l u t i o n g a s c h r o m a t o g r a p h y s i g n i f i c a n t l y e n h a n c e s compound i d e n t i f i c a t i o n capability. An e f f i c i e n t c l e a n - u p o f t h e s a m p l e i s a l s o c r i t i c a l f o r o b t a i n i n g i n t e r f e r e n c e - f r e e mass s p e c t r a . Ac kn o w l edg ement T h i s work was p a r t i a l l y s u p p o r t e d b y g r a n t R80593^010 a w a r d e d b y USEPA. We t h a n k D r . R. G i b b s a n d h i s a s s o c i a t e s o f t h e New Y o r k S t a t e D e p a r t m e n t o f E n v i r o n m e n t a l C o n s e r v a t i o n f o r c o l l e c t i o n and e x t r a c t i o n o f s a m p l e s .



368

Literature cited 1. 2. 3.


4. 5. 6.

Jones, P. W. and Leber, P. Ε., Eds., "Polynuclear Aromatic Hydrocarbons," Ann Arbor Science: Ann Arbor, Mich., 1979. Wotzak, G.; Gibbs, R.; and Hyde, J., "Proceedings of the International Symposium on the Health Effects of Diesel Engine Emissions," Cincinnati, December 1979 in press. Choudhury, D. R. and Bush, Β., "Proceedings of the Inter national Symposium on the Health Effects of Diesel Engine Emissions," Cincinnati, December 1979, in press. Bjorseth, Α., in "Polynuclear Aromatic Hydrocarbons," Jones, P. Ε., Eds., Ann Arbor Science: Ann Arbor, Mich., 1979. Choudhury, D. R., manuscript in preparation. Lee, M. L.; Vassilaros, D. L.; White, C. M.; and Novotny, Μ., Anal. Chem., 1979, 51, 768.

RECEIVED October 25, 1980.


Chemical Hazards in the Workplace - American Chemical Society

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