Organic Marine Geochemistry - American Chemical Society

4 Phenolic and Lignin Pyrolysis Products of Plants, Seston, and Sediment in a Georgia Estuary 1

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Jean K. Whelan , Martha E. Tarafa , and Evelyn B. Sherr 1

Chemistry Department, Woods Hole Oceanographic Institution, Woods Hole, MA 02543 University of Georgia Marine Institute, Sapelo Island, GA 31327

Downloaded by FUDAN UNIV on February 21, 2017 | http://pubs.acs.org Publication Date: April 21, 1986 | doi: 10.1021/bk-1986-0305.ch004

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Phenolic and lignin pyrolysis products measured i n plants, seston, and sediment i n a Georgia estuary together with isotopic data suggest that vascular plant material is present i n estuarine organic matter pools. The pyrolysis products together with isotopic patterns of this plant material do not resemble those obtained from Spartina. The pyrolysis-GC-MS data also gave indications of changes i n distribution of methoxy phenolic compounds i n going from plant materials to soils and seston, which could be due to either degradation processes or to a change in source in seston and sediments. These phenolic and methoxyphenolic pyrolysis products have generally not been detected to date i n either surface or sub-surface deep ocean sediments from several areas of the world. The combination of isotopic data, together with lignin and higher plant pyrolysis products, appears to provide a useful method of determining plant sources of organic matter i n estuaries. Determining the plant origins of organic matter i n coastal waters and sediments is of interest to geochemists and to écologiste i n answering specific questions regarding the sources and fates of carbon in these systems. For Georgia salt marsh estuaries, the i n i t i a l view was that most of the organic carbon present in the suspended material (seston) i n the water column, as well as i n the marsh soils and estuarine sediment, and which supported the estuarine food web, was derived from production of the marsh cordgrass, Spartina alterniflora (1-2). This concept has had to be modified based on stable carbon isotope analysis (3-5). Although the d i s tinctive isotopic signature of Spartina Γ = -12 to -13 ° / ) is present in the salt marsh soils and marsh animals, there is l i t t l e isotopic evidence for significant amounts of Spartina-derived organic matter i n the seston and sediment of the open estuary. Instead, there appears to be a large background of 00

0097-6156/ 86/ 0305-0062S06.00/ 0 © 1986 American Chemical Society

Sohn; Organic Marine Geochemistry ACS Symposium Series; American Chemical Society: Washington, DC, 1986.

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Phenolic and Lignin Pyrolysis Products 1 J

o r g a n i c carbon w i t h an i s o t o p i c c o m p o s i t i o n ( δ C o f -18 t o -24°/ ) depleted in compared to that of Spartina. S t a b l e carbon i s o t o p e a n a l y s i s a l o n e , however, cannot be used t o determine whether t h i s m a t e r i a l o r i g i n a t e s p r i m a r i l y from i n s i t u * phytoplankton production ( 6 C o f -20 t o -26°/ ) o r r e p r e s e n t s a m i x t u r e o f a l g a l carbon and S p a r t i n a d e t r i t u s w i t h t e r r e s t r i a l organic m a t t e r ( Ζ

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F i g u r e 2. L e v e l s o f v a n i l l y l d e r i v a t i v e s i n p y r o l y s i s p r o d u c t s of G e o r g i a e s t u a r y samples. Sample code: R i v e r s e s t o n (>52 Pm) ( R S ) ; Doboy Sound s e s t o n ( >52 μπι) (DSS); sediment from open creekbed ( S - 1 3 ) ; sediment from t i d a l c r e e k (marsh c r e e k b a n k ) ( S - l l ) ; sediment from t i d a l c r e e k (marsh c r e e k bed) ( S - 1 2 ) ; sediment from open e s t u a r y (Doboy m u d f l a t ) ( S - 1 5 ) ; mixed c y p r e s s and hard-wood (MCH); swamp s o i l ( S S ) ; b l a c k r u s h (BR); sedge ( s e d g ) ; w i l d r i c e (WR); and S p a r t i n a ( S p a r ) . See F i g u r e 1 f o r compound i d e n t i f i c a t i o n .


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the carbon s k e l e t o n s o f methoxy-phenolic p y r o l y s i s products are n o t d r a s t i c a l l y d i f f e r e n t from t h o s e found i n t h e p a r e n t l i g n i n (15-16, 18-19) and t h a t s t r u c t u r e s o f l i g n i n p y r o l y s i s p r o d u c t s r e p o r t e d h e r e a r e p r o b a b l y t h e same as t h o s e p r e v i o u s l y r e p o r t e d (11, 14). I n a d d i t i o n , two o f the samples a n a l y z e d i n t h i s work a r e a l s o b e i n g a n a l y z e d by p y r o l y s i s GCMS i n t h e l a b o r a t o r y o f Dr. Jap Boon i n the N e t h e r l a n d s w h i c h w i l l a l l o w comparison o f our mass s p e c t r a w i t h those of a u t h e n t i c standards. Because the bonded phase c a p i l l a r y GC columns b e i n g used i n b o t h l a b o r a t o r i e s have the same l i q u i d phase ( J . Boon, p r i v a t e communication), i t was asumed i n t h e p r e s e n t work t h a t t h e r e l a t i v e o r d e r o f GC e l u t i o n o f i s o m e r i c p y r o l y s i s p r o d u c t s was t h e same as i n R e f . (11) and i n o t h e r work o f S a i z - J i m e n e z and de Leeuw ( u n p u b l i s h e d m a n u s c r i p t ) . The v a n i l l y l and s y r i n g y l p y r o l y s i s p r o d u c t s shown i n F i g u r e 1 a r e p r o b a b l y c o r r e c t , a l t h o u g h t h e s e s t r u c t u r e s w i l l have t o be checked by comparison t o a u t h e n t i c s t a n d a r d s i n f u t u r e work. The mass s p e c t a l computer gave v e r y h i g h c o n f i d e n c e r a t i n g s ( g r e a t e r t h a n 900 out o f a p o s s i b l e 1000 on F i t , R f i t , and p u r i t y parameters on the I n c o s d a t a system) t o the s t r u c t u r e s shown i n F i g u r e 1 f o r compounds A-C, F, G, I , and M. The mass s p e c t r a f o r a l l o f t h e s e compounds a r e f a i r l y u n i q u e , as shown i n T a b l e I I . The computer i d e n t i f i e d compounds D, £ and H ( w h i c h p o s s e s s e d almost i d e n t i c a l mass s p e c t r a ) as p r o p e n y l v a n i l l y l compounds. The proposed s t r u c t u r e s shown i n F i g u r e 1 a r e based on the f a c t t h a t the p a r e n t l i g n i n c o n t a i n s o n l y s t r a i g h t ( r a t h e r than branched) C3 c h a i n s bonded t o t h e p h e n y l groups (18-19) and on t h e e x p e c t e d GC e l u t i o n o r d e r based on Réf. ( 1 1 ) . A f o u r t h compound, J i n F i g u r e 1, was a l s o i d e n t i f i e d by the computer as p r o p e n y l benzene. I t i s p r o posed t h a t t h i s compound c o n t a i n s a h y d r o x y l o r a l k o x y l group ( o r some o t h e r e a s i l y e l i m i n a t e d group) bonded t o a s t r a i g h t C3 s i d e c h a i n w h i c h i s e l i m i n a t e d d u r i n g e l e c t r o n impact f r a g m e n t a t i o n t o produce a mass spectrum v e r y s i m i l a r t o t h a t o f t h e c o r r e s p o n d i n g o l e f i n (20). S i m i l a r arguments a p p l y t o the p r o p e n y l s y r i n g y l compounds Κ and L. Compounds Τ and V were i d e n t i f i e d by the mass s p e c t a l com p u t e r as 3, 4-dimethoxyphenol and t r i m e t h o x y p h e n o l , r e s p e c t i v e l y . However, l i b r a r y s p e c t r a do n o t always c o n t a i n t h e c o r r e c t r e f e r ence isomers ( 1 1 ) . I n a d d i t i o n , because p y r o l y s i s p r o d u c t s t r u c t u r e s Τ and V i n F i g u r e 1 have been i d e n t i f i e d as abundant s y r i n g y l l i g n i n p y r o l y s i s p r o d u c t s ( 1 1 ) , and because i s o m e r s o f t e n g i v e v e r y s i m i l a r mass s p e c t r a ( 2 0 ) , we propose t h a t compounds Τ and V a r e actually the u n s u b s t i t u t e d and methyl syringyl derivatives, respectively. A number o f o t h e r p y r o l y s i s p r o d u c t s b e l i e v e d t o be e i t h e r phenols o r methoxyphenols d e r i v e d from h i g h e r p l a n t s were a l s o i d e n t i f i e d i n the sample s e t . I d e n t i f i c a t i o n o f t h e s e , i n c l u d i n g Ν t h r o u g h Ρ and S i n F i g u r e 4, a r e l e s s c e r t a i n t h a n t h o s e d i s cussed above so t h a t s t r u c t u r e s a r e n o t proposed. Compounds Q l , Q2, and U, w h i c h produce v e r y s i m i l a r mass s p e c t r a and, t h e r e f o r e , a r e proposed t o be i s o m e r i c ( 2 0 ) , were i d e n t i f i e d w i t h a h i g h degree o f c o n f i d e n c e by t h e mass spec computer as t h e d i p h e n o l i c s t r u c t u r e shown i n F i g u r e 1. Compounds R l and R2, w h i c h a l s o appear t o be i s o m e r i c , gave mass s p e c t r a v e r y s i m i l a r ( b u t not



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i d e n t i c a l ) t o thymol shown i n F i g u r e 1. T h e r e f o r e , we propose t h a t t h e s e two compounds, w h i c h o c c u r r e d w i d e l y i n t h e sample s e t , a r e terpene d e r i v a t i v e s r e l a t e d t o thymol. Computerized GCMS d a t a o f o t h e r samples o b t a i n e d from more marine sediments have a l s o been examined f o r the p o s s i b l e presence o f l i g n i n - d e r i v e d p y r o l y s i s p r o d u c t s (Whelan, u n p u b l i s h e d d a t a ) . Three marine g o r g o n i a n ( c o r a l ) samples showed o n l y t r a c e s o f com pound w h i c h might be G and o f a d i a l k y l p h e n o l . M a r i n e copepods, two sediment samples from a sub-bottom d e p t h o f 788 m n e a r the Canary I s l a n d s , a sediment sample from a sub-bottom d e p t h o f 564 m i n the Japan Trench, and two s u r f a c e sediment samples from t h e P e r u u p w e l l i n g r e g i o n a l l showed no t r a c e s o f t h e p y r o l y s i s p r o d u c t s shown i n F i g u r e s 1-4 (determined by c a r e f u l s e a r c h e s o f mass chromatograms o f t h e masses shown i n T a b l e 1) w i t h t h e p o s s i b l e e x c e p t i o n of compound U. The f a c t t h a t t h e s e marine samples g e n e r a l l y do not produce t h e s e p h e n o l i c and methoxy p h e n o l i c compounds s u p p o r t s the source o f t h e s e p y r o l y s i s p r o d u c t s as b e i n g non-marine, most p r o b a b l y from h i g h e r p l a n t s and/or l i g n i n . As shown i n F i g u r e 1, t h r e e g e n e r a l groups o f p h e n o l i c p y r o l y s i s p r o d u c t s were found i n t h e samples a n a l y s e d : v a n i l l y l p h e n o l s , s y r i n g y l p h e n o l s , and m i s c e l l a n e o u s p h e n o l i c and methoxy compounds. The r e l a t i v e p r o p o r t i o n s o f t h e i n d i v i d u a l p r o d u c t s i n t h e v a r i o u s samples i n each o f the t h r e e groups a r e p r e s e n t e d r e s p e c t i v e l y i n F i g u r e s 2-4. The v a n i l l y l type o f p h e n o l i c s t r u c t u r e i s produced i n the l i g n i n o f a l l v a s c u l a r p l a n t s (18-19). L e v e l s o f v a n i l l y l p h e n o l i c p y r o l y s i s p r o d u c t s were h i g h i n the p l a n t s , swamp s o i l , and i n s e s t o n i n the Altamaha R i v e r and i n Doboy Sounds ( F i g u r e 2 ) . In t h r e e of the e s t u a r i n e sediment samples, however, t h e s e compounds were e i t h e r u n d e t e c t e d o r found i n o n l y t r a c e amounts ( F i g u r e 2 ) . The a c e t y l d e r i v a t i v e , A, was c o n c e n t r a t e d i n swamp s o i l , i n r i v e r and e s t u a r i n e s e s t o n , and i n t h e S p a r t i n a creekbank sediment (S-ll). We p o s t u l a t e t h a t the s e s t o n and sediment have a s i g n i f i cant c o n t r i b u t i o n from swamp s o i l , o r more l i k e l y a l l o f t h e s e o r g a n i c p o o l s have a s i m i l a r p l a n t - d e r i v e d component w h i c h produces a h i g h e r p r o p o r t i o n o f t h e a c e t y l s t r u c t u r e upon p y r o l y s i s . The l a t t e r h y p o t h e s i s i s s u p p o r t e d by the presence o f the v a n i l l y l compound J i n s i g n i f i c a n t amounts o n l y i n S p a r t i n a and i n t h e S p a r t i n a marsh creekbank sediment ( S - l l ) . The low o r n o n - e x i s t e n t l e v e l s o f t h i s compound i n t h e o t h e r samples s u g g e s t s t h a t S p a r t i n a i s the major c o n t r i b u t o r o f h i g h e r p l a n t c a r b o n t o marsh creekbank sediment. However, i f t h i s h y p o t h e s i s i s c o r r e c t , i t i s d i f f i c u l t t o see why the s y r i n g l p r o d u c t s (K-M i n , F i g u r e 3) s h o u l d be p r e s e n t i n S p a r t i n a but m i s s i n g i n Sediment S - l l . F i v e s y r i n g y l d e r i v a t i v e s (compounds K-M, T, and V, F i g u r e 1) were d e t e c t e d among t h e p y r o l y s i s p r o d u c t s ( F i g u r e s 2-4). S y r i n g y l phenols a r e a l s o c h a r a c t e r i s t i c o f l l g n i n s , but o c c u r i n q u a n t i t y o n l y i n angiosperm p l a n t s C7; 18-19). S m a l l amounts o f t h r e e d i f f e r e n t a c e t y l and p r o p e n y l s y r i n g y l p y r o l y s i s p r o d u c t s were produced by w i l d r i c e and sedge ( F i g u r e 3 ) , w h i l e o n l y two o f t h e s e s t r u c t u r e s were o b t a i n e d from S p a r t i n a and the mixed c y p r e s s and hardwood t r e e l e a v e s . A much l a r g e r p r o p o r t i o n o f the a c e t y l d e r i v a t i v e , compound M, was found i n swamp s o i l and Doboy Sound



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s e s t o n , s u g g e s t i n g a common o r g a n i c source f o r t h e s e two p o o l s o f organic matter. Somewhat e l e v a t e d l e v e l s o f t h e s e t h r e e s y r i n g y l compounds o c c u r r e d i n r i v e r s e s t o n . The l o w e r p r o p o r t i o n o f com pound M t o L a s compared t o t h e Doboy Sound s e s t o n may I n d i c a t e a l e s s degraded o r a d i f f e r e n t p l a n t s o u r c e c o n t r i b u t i n g t o s e s t o n i n the r i v e r . The open e s t u a r y sediment samples, S-13 and S-15, had s y r i n g y l s t r u c t u r e s w h i c h p r o b a b l y came from p l a n t d e b r i s . I n c o n t r a s t , t h e creekbank s e d i m e n t , w h i c h had abundant v a n i l l y l s t r u c t u r e s , showed o n l y t h e u n s u b s t i t u t e d s y r i n g y l compound, T. The absence o f o t h e r s y r i n g y l s t r u c t u r e s i n sediment S - l l i s some what s u r p r i s i n g i f S p a r t i n a i s t h e main source o f p l a n t m a t e r i a l t o t h i s s e d i m e n t , s i n c e two a d d i t i o n a l s y r i n g y l s t r u c t u r e s ( L and M) were found among t h e S p a r t i n a p y r o l y s i s p r o d u c t s . F i g u r e 4 shows l e v e l s o f o t h e r phenoxy and methoxy p y r o l y s i s p r o d u c t s (N t h r o u g h S and U, some o f w h i c h a r e shown i n F i g u r e 1 ) w h i c h might be d e r i v e d from l i g n i n and/or o t h e r h i g h e r p l a n t material. The s p e c i f i c i t y o f t h e s e p y r o l y s i s p r o d u c t s a s markers o f h i g h e r p l a n t m a t e r i a l w i l l have t o be i n v e s t i g a t e d i n f u t u r e work. Q l and Q2 appear t o be a c e t y l d i p h e n o l i c s t r u c t u r e s , w h i l e b o t h R l and R2 were i d e n t i f i e d by t h e computer a s r e l a t e d t o t h y m o l (see F i g u r e 1 ) . B o t h t y p e s o f s t r u c t u r e s may be t y p i c a l o f h i g h e r p l a n t s , but a r e n o t n e c e s s a r i l y d e r i v e d from l i g n i n . Thymol ( R l and R2) i s a monoterpene w h i c h o c c u r s w i d e l y i n h i g h e r p l a n t s ( 2 1 ) . F o r t h e G e o r g i a e s t u a r y samples, t h e p l a n t s , swamp s o i l , s e s t o n , and sediment S - l l from t h e t i d a l creekbank a l l showed s i m i l a r d i s t r i b u t i o n s o f compounds Q2 and R l . Compound 0 a l s o o c c u r r e d as a p y r o l y s i s p r o d u c t i n t h e s e samples, w i t h t h e amount b e i n g more e n r i c h e d i n sedge t h a n i n t h e o t h e r p l a n t s . These com pounds a r e e i t h e r a b s e n t o r p r e s e n t i n l o w e r l e v e l s i n t h e s p e c t r a o f p y r o l y s i s p r o d u c t s from t h e o t h e r sediment samples: S-13, S-12 and S-15. The r e s u l t s a r e c o n s i s t e n t w i t h t h e v a n i l l y l product d i s t r i b u t i o n ( F i g u r e 2) and suggest t h a t t h e s e p y r o l y s i s p r o d u c t s a l s o a r i s e from v a s c u l a r p l a n t s and t h a t t h e r e i s a s i g n i f i c a n t v a s c u l a r p l a n t c o n t r i b u t i o n t o t h e s e s t o n and creekbank sediment. The s m a l l e r amounts o f compounds 0, Q2, and R l i n t h e open e s t u a r y sediments i n d i c a t e e i t h e r a l e s s e r i n f l u e n c e o r a more d i a g e n e t i c a l l y a l t e r e d higher p l a n t carbon. P y r o l y s i s p r o d u c t s N, R2, P, S, U, and V, shown i n F i g u r e 4, were more s p e c i f i c t h a n t h o s e d i s c u s s e d above. Compound V was produced o n l y by sedge, b l a c k r u s h , mixed c y p r e s s and hardwood l e a v e s , and i n s m a l l e r amounts, by swamp s o i l . The presence o f t h i s compound i n sediment S-15, b u t n o t i n o t h e r s e s t o n o r sediment samples, s u g g e s t s t h e c o n t r i b u t i o n o f s p e c i f i c h i g h e r p l a n t s t o t h i s sediment sample. The o c c u r r e n c e o f compound P, i n sediment S-15 and Doboy Sound s e s t o n , b u t n o t i n t h e h i g h e r p l a n t s a n a l y z e d o r i n swamp s o i l may i n d i c a t e a f a i r l y s p e c i f i c marine p r e c u r s o r f o r t h i s p a r t i c u l a r p y r o l y s i s product. I n a d d i t i o n t o t h e a n a l y s e s o f l i g n i n p r o d u c t s by PGCMS a s d i s c u s s e d h e r e , one sample o f e s t u a r i n e s e d i m e n t , comparable t o sample S-15, was a n a l y z e d f o r l i g n i n o x i d a t i o n p r o d u c t s by t h e CuO o x i d a t i o n method ( 2 2 ) . The d i s t r i b u t i o n o f v a r i o u s t y p e s o f p h e n o l i c compounds i n t h e sediment I s compared t o t h a t o f S p a r t i n a


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a l t e m i f l o r a and o t h e r t y p e s o f p l a n t s p r e v i o u s l y a n a l y z e d w i t h the CuO method (7) i n T a b l e I I I .

T a b l e I I I . Comparison o f t h r e e l i g n i n parameters d e t e r m i n e d f o r an e s t u a r i n e sediment sample w i t h t h o s e o f S p a r t i n a a l t e m i f l o r a and o t h e r v a s c u l a r p l a n t s . S/V wt. r a t i o o f s y r i n g y l t o v a n i l l y l p h e n o l s ; C/V wt. r a t i o o f c i n n a m y l t o v a n i l l y l p h e n o l s ; Co/Fe wt. r a t i o o f the c i n n a m y l p h e n o l s p-coumaric a c i d and f e r u l i c a c i d . m

s

β


Sample E s t u a r i n e sediment *Spartina a l t e m i f l o r a Other nonwoody angiosperm t i s s u e Angiosperm woods Gymnosperm nonwoody t i s s u e Gymnosperm woods

S/V

C/V

1.24 1.1 1.5 2.5 0.02 0

0.46 1.0 0.71 0 0.49 0

* p l a n t d a t a from Ref.

Co/Fe 2.89 0.84 2.5 0 5.0 0

7.

The l i g n i n s i g n a t u r e i n t h i s sediment sample most c l o s e l y resembles t h a t o f nonwoody angiosperm t i s s u e , but i t does n o t f i t w e l l w i t h the s p e c i f i c d i s t r i b u t i o n o f l i g n i n phenols o b t a i n e d f o r S p a r t i n a . T h i s r e s u l t i s c o n s i s t e n t w i t h t h o s e o b t a i n e d by PGCMS, even though the s p e c i f i c r e l a t i o n between o x i d a t i v e and p y r o l y t i c l i g n i n d e g r a d a t i o n p r o d u c t s has n o t y e t been d e t e r m i n e d . Thus, sediment S-15 does not show the same p y r o l y s i s p r o d u c t s as S p a r t i n a i n F i g u r e s 2-4. The s t r o n g e s t p h e n o l i c p y r o l y s i s s i g n a l i n S-15 i s most l i k e t h o s e o f swamp s o i l and Doboy Sound s e s t o n as shown i n F i g u r e 3 and c o n s i s t s o f a r e l a t i v e l y s t r o n g s y r i n g y l component i n c o m p a r i son t o o t h e r sediment samples. S e v e r a l sediment samples from the M i s s i s s i p p i Fan i n the G u l f o f Mexico d i d show t r a c e s o f compound U. These sediments s h o u l d have been h e a v i l y i n f l u e n c e d by t e r r i g e n o u s o r g a n i c m a t t e r . How e v e r , i t i s not c u r r e n t l y known t o what depths l i g n i n s s u r v i v e i n deep sea sediments ( 6 ) . I t has r e c e n t l y been shown t h a t v a n i l l y l and p-hydroxy l i g n i n a r e p a r t i a l l y p r e s e r v e d i n some b u r i e d woods f o r p e r i o d s o f up t o 2500 y e a r s ( 2 3 ) . We p l a n t o r e a n a l y z e DSDP M i s s i s s i p p i Fan samples, a l o n g w i t h more h e m i p e l a g i c types of marine s e d i m e n t s , i n f u t u r e work t o l o o k i n d e t a i l f o r the com pounds i n F i g u r e 1. Summary D e t e r m i n i n g the r e l a t i v e c o n t r i b u t i o n s o f marine and t e r r e s t r i a l p l a n t o r g a n i c carbon t o t h e p o o l s o f o r g a n i c m a t t e r i n c o a s t a l systems i s o f t e n d i f f i c u l t . I n G e o r g i a s a l t marsh e s t u a r i e s , the major s o u r c e s o f o r g a n i c m a t t e r a r e i n s i t u p h y t o p l a n k t o n produc-




74

t i o n , d e t r i t u s from t h e marsh g r a s s S p a r t i n a a l t e m i f l o r a , and t e r r e s t r i a l p l a n t m a t e r i a l i n t r o d u c e d by r i v e r f l o w . S t a b l e carbon i s o t o p e s t u d i e s i n d i c a t e t h a t , a l t h o u g h S p a r t i n a carbon i s p r e s e n t i n s a l t marsh sediment and t o some e x t e n t i n sediment i n t h e open e s t u a r y , t h e r e i s a l a r g e background of ^C-depleted organic m a t t e r i n sediment and i n suspended p a r t i c u l a t e m a t e r i a l w h i c h c o u l d come e i t h e r from p h y t o p l a n k t o n o r from t e r r e s t r i a l m a t e r i a l . I n o r d e r t o c l a r i f y t h e s o u r c e o f t h i s m a t e r i a l , samples o f e s t u a r i n e v a s c u l a r p l a n t s , s e s t o n , and sediment were a n a l y s e d f o r con t e n t and c o m p o s i t i o n o f p h e n o l i c and methoxy p h e n o l i c p y r o l y s i s p r o d u c t s by p y r o l y s i s and subsequent gas chromatography and mass s p e c t r o m e t r y . Some o r a l l o f t h e s e p r o d u c t s ( p a r t i c u l a r l y t h e methoxy p h e n o l s ) a r e proposed t o be d i a g n o s t i c l i g n i n p y r o l y s i s products. These p r o d u c t s , w h i c h a r e n o t produced by more marine samples, appear t o be d i a g n o s t i c o f t e r r i g e n o u s p l a n t s . Based on t h e s e a n a l y s e s , S p a r t i n a has a unique s i g n a t u r e w h i c h a l s o appeared i n a sample o f s u r f a c e mud from t h e bank o f a t i d a l c r e e k d r a i n i n g a S p a r t i n a marsh. Sediment from t h e t i d a l c r e e k bed and from two open e s t u a r i n e s i t e s showed v e r y l i t t l e o f t h e s e p y r o l y s i s p r o d u c t s , and t h e c o m p o s i t i o n d i d n o t match t h a t o f S p a r t i n a . Suspen ded m a t e r i a l i n t h e e s t u a r y had a s t r o n g e r s i g n a l w h i c h resembled t h a t o f t r e e l e a v e s and s o i l i n c o a s t a l f r e s h w a t e r swamps. S e s t o n and some sediment i n t h e open e s t u a r y a l s o c o n t a i n e d p h e n o l i c ( p r o b a b l y n o n - l i g n i n ) p y r o l y s i s p r o d u c t s w h i c h were n o t p r e s e n t i n the p l a n t s and w h i c h were p r o b a b l y o f marine o r i g i n . One e s t u a r i n e sediment sample was i n d e p e n d e n t l y a n a l y s e d f o r l i g n i n CuO o x i d a t i o n p r o d u c t s v i a gas chromatography. The c o m p o s i t i o n o f t h e l i g n i n p r e s e n t i n t h i s sample resembled t h a t o f some non-woody angiosperm t i s s u e s from t h e swamp, b u t d i d n o t c l o s e l y match t h e l i g n i n p r o d u c t s found f o r S p a r t i n a . I t appears t h a t o r g a n i c carbon d e r i v e d from v a s c u l a r p l a n t s i s p r e s e n t i n e s t u a r i n e s e s t o n and sediment, b u t S p a r t i n a may n o t be t h e p r i m a r y s o u r c e f o r t h i s material. Acknowledgments T h i s work was s u p p o r t e d by g r a n t s from t h e Sapelo I s l a n d R e s e a r c h F o u n d a t i o n t o E. S h e r r and by N a t i o n a l S c i e n c e F o u n d a t i o n Grant OCE83-00485 t o J . K. Whelan and J . M. Hunt. We a r e g r a t e f u l t o Dr. John Hedges f o r l i g n i n o x i d a t i o n p r o d u c t a n a l y s i s o f one o f our sediment samples, and t o D r s . J i m A l b e r t s , Chuck Hopkinson, John E r t e l and John Hedges f o r t h e i r comments on t h e m a n u s c r i p t . Thanks a l s o go t o Dr. N e l s o n Frew f o r mass s p e c t r a and t o C h r i s t i n e B u r t o n and R i c h a r d Sawdo f o r t e c h n i c a l a s s i s t a n c e . C o n t r i b u t i o n No. 6055 o f t h e Woods Hole Océanographie I n s t i t u t i o n and No. 546 of t h e U n i v e r s i t y o f G e o r g i a M a r i n e I n s t i t u t e .

Literature Cited 1. 2.

Teal, J . M . , Ecology 1962, 43, 614-624. Odum, E. P.; De La Cruz, A. A. In "Estuaries"; Lauff, G. H . , Ed.; AMER. ASSOC. ADV. SCIENCE: Washington, D.C., 1967; pp. 383-388.


4. WHELAN ET AL. Phenolic and Lignin Pyrolysis Products

3. 4. 5. 6. 7. 8. 9. 10.


11. 12. 13. 14. 15. 16. 17. 18 19. 20. 21. 22. 23.

Haines, Ε. B. Oikos, 1977, 19, 254-260. Haines, Ε. B . ; Montague, C. L. Ecology 1979, 60, 48-56. Sherr, Ε. B. Geochim. Cosmochim. Acta 1982, 46, 1227-1232. Hedges, J. I.; Mann, D.C. Geochim. Cosmochim. Acta 1979, 43, 1809-1818. Hedges, J. I.; Mann, D.C. Geochim. Cosmochim. Acta 1979, 43, 1803-1807. Hedges, J. I.; Parker, P.L. Geochim. Cosmochim. Acta 1976, 40, 1019-1029. Hedges, J. I.; Turin, H. J.; Ertel, J. R. Limnol. Oceanogr. 1984, 29, 35-45. Ertel, J. R.; Hedges, H. I. Geochim. Cosmochim. Acta 1984, 48, 2065-2074. Saiz-Jimenez, C.; de Leeuw, J. W. Org. Geochem. 1984, 6, 417-422. Bracewell, J. M.; Robertson, G. W.; Williams, B. L. J. Anal. Appl. Pyr. 1980, 2, 53-62. Sigleo, A. C.; Hoering, T.C.; Helz, G. R. Geochim. Cosmochim. Acta 1982, 46, 1619-1626. Van de Meent, D.; DeLeeuw, J.W.; Schenek, P.A. J. Anal. Appl. Pyr. 1980, 2, 249-263. Obst, J. R. J. Wood Chem. Technol. 1983, 3, pp. 377-397. Martin, F . ; Saiz-Jimenez, C.; Gonsalez-Vila, F. J. Holzforschung 1979, 33, 210-212. Whelan, J. K . ; Fitzgerald, M. G.; Tarafa, M. Environ. S c i . Tech. 1983, 17, 292-298. Sarkanen, Κ. V. In "The Chemistry of Wood"; Browning, B. L., Ed.; R. E. Krieger Publishing Co.: Florida, 1963 (reprinted 1981); pp. 249-311. Sarkanen, Κ. V . ; Ludwig, C. H. "Lignins"; Wiley-Interscience: New York, 1981. Biemann, K. "Mass Spectrometry"; McGraw Hill: N.Y. 1962; pp. 87-95. Buchanan, M.A. In "The Chemistry of Wood", Browning, B. L., ed.; R. E. Krieger Publishing Co.: Florida, 1963; pp. 324-325. Hedges, J. I.; E r t e l , J. R. Anal. Chem. 1982, 54, 174-178. Hedges, J. I.; Cowie, G. L.; E r t e l , J. R.; Barbour, R. J.; Hatcher, P.G. Geochim. Cosmchim. Acta 1985, 49, 701-711.

RECEIVED October 31, 1985


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Organic Marine Geochemistry - American Chemical Society

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