are all creatures created equal? (chemistry of biosphere)

Are All Creatures Created Equal?(Chemistry of biosphere)

Yuan-Hui (Telu) Li

Department of Oceanography

University of Hawaii at Manoa

Outline

• Chemical compositions of terrestrial and marine organisms

• Biophile and biophobe elements• Surface complexation model• Human beings as a part of nature• Fossil carbon: black shale, coal and crude oil• Conclusions• Acknowledgment

Data by Bowen (1979)

Biological standard reference materials (SRM)

Biophile: major ions in seawater, and B-type cations (d-shell electrons 5-10; high polarizability).

Biophobe: A-type cations (electron configurations of noble gases; low polarizability).

Wackett et al. (2004)

Hydration of metal oxide surface: O O O O O O Si Si Si Si SiO O O O O O + n H2O Si Si Si Si Si    H H H H O O O O O O O O Si Si Si Si SiO O O O O O Si Si Si Si Si  

Surface complexation model:Amphoteric property of oxide and organic matter surfaces:For Cations M+z :

M+z + MeOH MeO‑M+z‑1 + H+

Me are mostly Si, Fe, and Mn

K = {MeO‑M+z‑1 }[H+ ]/[M+z ]{MeOH }

= Kd [H+]/{MeOH }

M+z + R-LH R-L‑M+z‑1 + H+

L are organic ligands with hydrophilic functional groups, such as R-OH, R-NH2, and R-SH, on the surface of organic particles.The relative O-M and L-M bond strengths for various cations are shown to be proportional to K, Kd, and the electron bonding energy to gaseous ions (Iz), i.e.

M+z (g) + e- M+z-1 (g) + Iz

A (g) + e- A-1 (g) + I-1

For anions Az (e.g. Cl-, HS-; SO4-2, MoO4

-2, ReO4-)

Az + MeOH Me-A-z+1 + OH

Az + R-OH R-A-z+1 + OH

The relative Me-A and R-A bond strengths are proportional to

the I-1 of simple anions, or inversely related to the Iz of the

central cation of oxyanion.

Me-Cl R-Cl

O O Me-O-S-O R-O-S-O

O O

M+z + L-4 ML+z-4

= [ML+z-4]/([M+z ][L-4]

Mean residence time =

urine

mam

urine

man

C

X

CF

XM50

-0.5

0.0

0.5

1.0

F2

-0.5

0.0

0.5

1.0

F4

-8

-6

-4

-2

0

2

F2

scor

e

-2

0

2

4

F4

scor

e

-1.0 -0.5 0.0 0.5 1.0F1

-1.0 -0.5 0.0 0.5 1.0F3

-3 -2 -1 0 1 2 3F1 score

-2 -1 0 1 2 3 4 5F3 score

UZr

K

Al

Ca

Cu

NiOC

Zn

Ba

Mo

ICRb Y

(a) (b)

(c) (d)

Co

SrSi

Ti V

Sr

U

P

Cretaceousblack shale

Mg

S

AsFe

CaIC

Mn

OC rich S rich

OC rich S rich

0

10

20

30

40

OC

(%

)

0

100

200

300

400

500

Mo

(ppm

)

0

2

4

6

8

10

12

CaO

(%

)

0

10

20

30

40

OC

(%

)0

10

20

30

ex F

e2O

3 (%

)0

10

20

30

Fe2

O3

(%)

40 50 60 70Depth (cm)

0 10 20 30 40OC (%)

0.00 0.01 0.02 0.03 0.04 0.05MnO (%)

0 5 10 15 20 25S (%)

0 5 10 15 20 25S (%)

5 10 15Al2O3 (%)

(a)

(e) (f)

(b)

(d)(c)

pyrite

Black shale OC-rich S-rich

shale

Conclusions1. The relative abundances of elements in marine and terrestrial living organisms, including human being, are remarkably similar.2. Enrichment of biophile elements relative to soil or pelagic clays mainly reflect the formation of extra strong bonds between highly polarizable biophile elements and organic ligands containing -NH2, -SH, and -COOH groups.3. The mean residence times of elements in the human body again can be explained by the concept of the relative bond strength between ions and organic matter.4. The enriched biophile elements in coals are mainly associated with sulfide phases.5. The enriched biophile elements in crude oils are mainly concentrated in the resin and asphaltene fractions.

Acknowledgement: Many thanks are due to Professor Yoshiki Sohrin, who has graciously sponsored my visit at the Kyoto University. The pioneering works by Professor Toshio Yamamoto on seaweeds are acknowledged here.