Andr ei Medvedovici Depa r t ment of Ana l yt ica l Chemist r y, Fa cul t y of Chemist r y, Univer sit y of Bucha r est , # 90-92 Pa ndur i Ave., Bucha r est -050663, Roma nia Fa x no. + 40214102279; E-ma il : a vmedved@ ya hoo.com INTERNATIONAL W ORKSHO P “CHALLENGES IN FO OD CHEMISTRY” – June 1, 2013 Ma y 31 Const a nt a , Rom a nia
dur ing l if e is immor a l , il l ega l or Mur phy La w: Ever yt hing nice get s FAT!
Tr igl ycer ides: TGs O ... O H 2 C O ... O CH ... H 2 C O TGs O ... DGs O ... MGs * O O O FFA H ... O Chiral! O Position: -saturated; SOL OLS OSL -unsaturated -polyunsaturated -place of the =
O O Si O Si N O Ag + H SFC Column: Nucleosil 100-5 SA (Ag + ) form, 25 cm L x 4.6 mm i.d. x 5 um d.p. Column temperature: 65 o C; Pressure: 150 bar (2 min) 300 bar: [1.5 bar/min] Modifier: ACN/2-PrOH : 6/4 Modifier programming: 1.2% (2 min) 7.2% (28 min): [0.3%/min] 12.2%: [0.54%/min] Flow rate: 1 mL/min
Positional isomers can be identified based on diglyceride ion ratios. (Equipment dependent)! In CIS the [M+Ag + ] ion shows the highest intensity irrespective to the degree of unsaturation. (Equipment independent). Fully saturated TGs can be characterized through CIS. (Equipment independent).
First dimension: PSFC on C18 Column: 2 x Adsorbosphere C18, 25 cm L x 4.6 mm i.d. x 5 um d.p. Column temperature: 25 o C; Pressure: 150 bar Modifier: ACN/2-PrOH : 6/4; 2.5% in CO 2 isocratic Flow rate: 2 mL/min
JOJOBA Seeds ( Simmondsia Chinesis ) orig. Sonora Desert – U.S. Jojoba Oil, light yellow, odorless Ri Rj C O C i:n / C j:m O Jojoba Oil / Hydrolysis Fatty Acids Fatty Alcohols Methylation GC Analysis OV-1 - FAMEs mass distribution; Carbowax - FAs mass distribution CN – unsaturation
+ . N 2 + + e - 2 e - N 2 + . [CH 3 OH] + + + N 2 CH 3 OH N 2 H . [CH 3 OH] + + [CH 3 OH 2 ] + + + CH 3 OH CH 2 O O O + + + [CH 3 OH 2 ] + Ri O Rj Ri O Rj CH 3 OH H O O + + + Ri O Rj Ri OH R(j- 1 ) H + H O + + + R(i- 2 ) Ri O Rj Rj OH H 2 CO H O H 2 O + CO + R(i- 2 ) Ri OH + R(j- 1 ) Rj OH H 2 O
Column Spherisorb BDS 25 cm x 2.0 mm x 5 m M. Phase MeOH / Acetone / Hexane 2 / 1 / 1 Elution Isocratic Flow 0.2 mL/min 10 L/min (post column) AgNO 3 flow 10 L Vol. Inj. MS (+) mode Gas Temp. 200 °C Gas Flow 12 L/min Nebulizing P. 45 psi Cap. Voltage 5 kV Mass Scan 100-800 m/e CID Voltage 290 V RETENTION RULE Acc. to ECN (Equivalent Chain Number) ECN = CN – 2 NDB Ex. C x H 2x CN = x; NDB = 1; ECN = x-1 C (i+2):2 elutes before C i:1
Author acknowledges the financial support given through the Romanian project PNII_ID_PCE_2011_3_0152.
Recommend
More recommend
