Insights into the Sorption Properties of Cutin and Cutan Biopolymers

Abstract

Plant cuticles have been reported as highly efficient sorbents for organic compounds. The objective of this study was to elucidate the sorption and desorption behavior of polar and nonpolar organic compounds with the major structural components of the plant cuticle: the biopolymers cutin and cutan. The sorption affinity values of the studied compounds followed the order: phenanthrene > atrazine > chlorotoluron > carbamazepine. A higher sorption affinity of phenanthrene and atrazine to cutin was probably due to the higher level of amorphous paraffinic carbon in this biopolymer. Phenanthrene exhibited reversible sorption behavior and a high ratio of organic-carbon-normalized distribution coefficient (Koc) to carbon-normalized octanol-water partitioning coefficients (Kowc) with both biopolymers. This suggests that both biopolymers provide phenanthrene with a partition medium for hydrophobic interactions with the flexible long alkyl-chain moieties of the biopolymers. The low Koc/Kowc ratios obtained for the polar sorbates suggest that the polar sites in the biopolymers are not accessible for sorption interactions. Atrazine and carbamazepine exhibited sorption-desorption hysteresis with both sorbents, indicating that both sorbates interact with cutin and cutan via both hydrophobic and specific interactions. In general, the sorptive properties of the studied biopolymers were similar, signifying that the active sorption sites are similar even though the biopolymers exhibit different properties.

Sorption characteristics and contribution of organic matter fractions for atrazine in soil

“…4), indicating that the polarity of the SOM fractions has a significant effect on the sorption capacity of atrazine. It has also been reported that higher-polarity biopolymers have a higher sorption affinity for atrazine (Shechter and Chefetz 2008), and atrazine sorption by humic substances exhibited a positive correlation with the substances' polar carbon contents (Wang et al 2011). However, this result differs from the previous reports on the sorption of apolar HOCs such as phenanthrene and lindance by fractionated SOM, which described a negative relationship between SOM polarity and logK OC (Kang and Xing 2005;Wang et al 2011).…”

Reconstitution of cutin monomers on smectite surfaces: adsorption and esterification

“…The peaks are assigned to carbonyl stretching associated with free carboxyl, H-bond carboxyl and ester bonds, respectively (Heredia-Guerrero et al, 2010). The peak at 1731 cm −1 was clearly observed in the cutin biopolymer that was used to isolate the studied monomers (Shechter and Chefetz, 2008). The spectrum of the cutin monomers exhibited a shoulder at wavenumber 1731 cm −1 , whereas this peak is clearly observed in the spectra of all montmorillonitemonomer complexes.…”

“…Monomers of cutin were isolated from tomato (Lycopersicon esculentum) fruit cuticle using the previously reported method (Shechter and Chefetz, 2008). Briefly, tomato fruit peels were treated with oxalic acid and ammonium oxalate solution to remove noncuticular matter.…”

Sorption of polyaromatic compounds by organic matter-coated Ca2+– and Fe3+–montmorillonite

“…Cuticular waxes were isolated from the leaves of Agave americana as described in Shechter and Chefetz (2008). Waxes were extracted from manually peeled cuticular sheets by Soxhlet extraction with chloroform/methanol (1:1 v/v) for 6 h. The solvent was evaporated at 40°C under vacuum, and waxes were freeze-dried, ground and sieved.…”

“…The outer surface of the cuticle is covered with waxes, which consist of a complex mixture of long-chain aliphatic and cyclic components in crystalline and amorphous phases (Santier and Chamel, 1998;Chen and Xing, 2005). A number of reports have demonstrated that cuticular materials are efficient natural sorbents for hydrophobic organic compounds (HOCs) (Chefetz et al, 2000;2003;Shechter and Chefetz, 2008).…”