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Green synthesis of a typical chiral stationary phase of cellulose-tris(3, 5-dimethylphenylcarbamate).

Liu RQ, Bai LY, Zhang YJ, Zhang YP - Chem Cent J (2013)

Bottom Line: The synthesized CDMPC was then coated onto the surfaces of aminopropyl silica gel to prepare a chiral stationary phase (CSP).The prepared CSP was successfully used in chiral separation of seven racemic pesticides by high performance liquid chromatography (HPLC).The experimental results suggested it was a good choice using a green solvent of AmimCl for cellulose functionalization.

View Article: PubMed Central - HTML - PubMed

Affiliation: College of Plant Protection, Hunan Agricultural University, Changsha 410128, P,R, China. blyang2006@163.com.

ABSTRACT

Background: At present, the study on the homogeneous-phase derivatization of cellulose in ionic liquid is mainly focused on its acetylation. To the best of our knowledge, there has been no such report on the preparation of cellulose-tris(3,5-dimethylphenylcarbamate) (CDMPC) with ionic liquid 1-allyl-3-methyl-imidazolium chloride (AmimCl) so far.

Results: With ionic liquid 1-allyl-3-methylimidazolium chloride (AmimCl) as a reaction solvent, cellulose-tris(3,5-dimethylphenylcarbamate) (CDMPC) was synthesized by the reaction of 3,5-dimethylphenyl isocyanate and soluble microcrystalline cellulose in a homogeneous phase. The synthesized CDMPC was then coated onto the surfaces of aminopropyl silica gel to prepare a chiral stationary phase (CSP). The prepared CSP was successfully used in chiral separation of seven racemic pesticides by high performance liquid chromatography (HPLC). Good chiral separation was obtained using n-hexane and different modifiers as the mobile phases under the optimal percentage and column temperature, with the resolution of metalaxyl, diniconazole, flutriafol, paclobutrazol, hexaconazole, myclobutanil and hexythiazox of 1.73, 1.56, 1.26, 1.00, 1.18, 1.14 and 1.51, respectively. The experimental results suggested it was a good choice using a green solvent of AmimCl for cellulose functionalization.

Conclusion: CDMPC was successfully synthesized as the chiral selector by reacting 3, 5-dimethylphenyl isocyanate with dissolved microcrystalline cellulose in a green ionic liquid of AmimCl.

No MeSH data available.


Related in: MedlinePlus

Optimal chromatograms of the selected pesticides and their molecular structures. Pesticide identification: (a) metalaxyl, (b) flutriafol, (c) diniconazole, (d) paclobutrazol, (e) hexaconazole, (f) hexythiazox, (g) myclobutanil.
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Figure 4: Optimal chromatograms of the selected pesticides and their molecular structures. Pesticide identification: (a) metalaxyl, (b) flutriafol, (c) diniconazole, (d) paclobutrazol, (e) hexaconazole, (f) hexythiazox, (g) myclobutanil.

Mentions: Diniconazole, flutriafol, paclobutrazol and hexaconazole all contain benzene rings and hydroxyls in their molecular structures, hexythiazox and metalaxyl contain benzene rings and carbonyls in their molecular structures, myclobutanil, diniconazole, paclobutrazol and hexaconazole contain chlorphenyls and 1, 2, 4-triazolyls in their molecules. The above groups may have dipole-dipole interaction, hydrogen bond interaction and π-π interaction with the stationary phases. Generally, the polarity of mobile phase can be changed by changing the alcohol ratio in mobile phase, which in turn affects the retention time and resolution in enantioseparation [17]. In order to preliminarily study the separation effects of seven racemic pesticides and investigate the impact of polarity on separation, we selected isopropanol as the polar modifier. The impact of modifier (isopropanol/ethanol) and separation temperature on the retention time and stereo selectivity of enantiomer separation of 7 racemic pesticides on the self-made CDMPC chiral column were investigated in detail. When n-hexane/isopropanol (98/2, v/v) were used as the mobile phases with a flow rate of 1.0 ml/min at 25°C, the resolution of paclobutrazol, hexaconazole and hexythiazox was 1.00, 1.18 and 1.51, respectively, the resolution of diniconazole was 1.56 when n-hexane/isopropanol (80/20, v/v) were used as the mobile phases at 25°C, the resolution of flutriafol was 1.26 when n-hexane/isopropanol (95/5, v/v) were used as the mobile phases at 20°C, the resolution of myclobutanil was 1.14 when n-hexane/isopropanol (85/15, v/v) were used as the mobile phases at 25°C, the resolution of metalaxyl was 1.73 when n-hexane/ethanol (95/5, v/v) were used as the mobile phases at 25°C. The optimal separation chromatograms of 7 racemic pesticides were shown in Table 1 and Figure 4.


Green synthesis of a typical chiral stationary phase of cellulose-tris(3, 5-dimethylphenylcarbamate).

Liu RQ, Bai LY, Zhang YJ, Zhang YP - Chem Cent J (2013)

Optimal chromatograms of the selected pesticides and their molecular structures. Pesticide identification: (a) metalaxyl, (b) flutriafol, (c) diniconazole, (d) paclobutrazol, (e) hexaconazole, (f) hexythiazox, (g) myclobutanil.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3750357&req=5

Figure 4: Optimal chromatograms of the selected pesticides and their molecular structures. Pesticide identification: (a) metalaxyl, (b) flutriafol, (c) diniconazole, (d) paclobutrazol, (e) hexaconazole, (f) hexythiazox, (g) myclobutanil.
Mentions: Diniconazole, flutriafol, paclobutrazol and hexaconazole all contain benzene rings and hydroxyls in their molecular structures, hexythiazox and metalaxyl contain benzene rings and carbonyls in their molecular structures, myclobutanil, diniconazole, paclobutrazol and hexaconazole contain chlorphenyls and 1, 2, 4-triazolyls in their molecules. The above groups may have dipole-dipole interaction, hydrogen bond interaction and π-π interaction with the stationary phases. Generally, the polarity of mobile phase can be changed by changing the alcohol ratio in mobile phase, which in turn affects the retention time and resolution in enantioseparation [17]. In order to preliminarily study the separation effects of seven racemic pesticides and investigate the impact of polarity on separation, we selected isopropanol as the polar modifier. The impact of modifier (isopropanol/ethanol) and separation temperature on the retention time and stereo selectivity of enantiomer separation of 7 racemic pesticides on the self-made CDMPC chiral column were investigated in detail. When n-hexane/isopropanol (98/2, v/v) were used as the mobile phases with a flow rate of 1.0 ml/min at 25°C, the resolution of paclobutrazol, hexaconazole and hexythiazox was 1.00, 1.18 and 1.51, respectively, the resolution of diniconazole was 1.56 when n-hexane/isopropanol (80/20, v/v) were used as the mobile phases at 25°C, the resolution of flutriafol was 1.26 when n-hexane/isopropanol (95/5, v/v) were used as the mobile phases at 20°C, the resolution of myclobutanil was 1.14 when n-hexane/isopropanol (85/15, v/v) were used as the mobile phases at 25°C, the resolution of metalaxyl was 1.73 when n-hexane/ethanol (95/5, v/v) were used as the mobile phases at 25°C. The optimal separation chromatograms of 7 racemic pesticides were shown in Table 1 and Figure 4.

Bottom Line: The synthesized CDMPC was then coated onto the surfaces of aminopropyl silica gel to prepare a chiral stationary phase (CSP).The prepared CSP was successfully used in chiral separation of seven racemic pesticides by high performance liquid chromatography (HPLC).The experimental results suggested it was a good choice using a green solvent of AmimCl for cellulose functionalization.

View Article: PubMed Central - HTML - PubMed

Affiliation: College of Plant Protection, Hunan Agricultural University, Changsha 410128, P,R, China. blyang2006@163.com.

ABSTRACT

Background: At present, the study on the homogeneous-phase derivatization of cellulose in ionic liquid is mainly focused on its acetylation. To the best of our knowledge, there has been no such report on the preparation of cellulose-tris(3,5-dimethylphenylcarbamate) (CDMPC) with ionic liquid 1-allyl-3-methyl-imidazolium chloride (AmimCl) so far.

Results: With ionic liquid 1-allyl-3-methylimidazolium chloride (AmimCl) as a reaction solvent, cellulose-tris(3,5-dimethylphenylcarbamate) (CDMPC) was synthesized by the reaction of 3,5-dimethylphenyl isocyanate and soluble microcrystalline cellulose in a homogeneous phase. The synthesized CDMPC was then coated onto the surfaces of aminopropyl silica gel to prepare a chiral stationary phase (CSP). The prepared CSP was successfully used in chiral separation of seven racemic pesticides by high performance liquid chromatography (HPLC). Good chiral separation was obtained using n-hexane and different modifiers as the mobile phases under the optimal percentage and column temperature, with the resolution of metalaxyl, diniconazole, flutriafol, paclobutrazol, hexaconazole, myclobutanil and hexythiazox of 1.73, 1.56, 1.26, 1.00, 1.18, 1.14 and 1.51, respectively. The experimental results suggested it was a good choice using a green solvent of AmimCl for cellulose functionalization.

Conclusion: CDMPC was successfully synthesized as the chiral selector by reacting 3, 5-dimethylphenyl isocyanate with dissolved microcrystalline cellulose in a green ionic liquid of AmimCl.

No MeSH data available.


Related in: MedlinePlus