INTEREST OF HPTLC FOR FOSSIL DERIVED PRODUCTS ANALYSIS : A SIMPLE APPROACH TO HYDROCARBON GROUP TYPE ANALYSIS

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2 INTEREST OF HPTLC FOR FOSSIL DERIVED PRODUCTS ANALYSIS : A SIMPLE APPROACH TO HYDROCARBON GROUP TYPE ANALYSIS Muriel Matt 1,2, Vicente L. Cebolla 1, Luis Membrado 1, Eva M. Galvez 1, Jesus Vela 1, Robert Bacaud 3 1 :Instituto de Carboquimica, CSIC, Zaragoza. Spain 2 : LTAC, Université de Metz. France 3 : Institut de Recherches sur la Catalyse, CNRS, Lyon. France Acknowledgements to :

3 Polar compounds planar chromatography HPTLC plates UV and Fluorescence scanning densitometry Horizontal developing chamber

4 Interests Why HTA for fossil derived products? Fuel formulation To follow a process Legislation Products of thermal pyrolysis Coal conversion Desulfurization of fuel PACs Problem of standards Planar Chromatography The whole sample is analyzed Rapidity Automation

5 Detection of Alkanes and Naphthenes Saturated compounds are not detected in UV/Visible region Have no fluorescent properties hν O O Fluorescence emission H 3 CO OCH 3 N+ BERBERINE-INDUCED FLUORESCENCE Analyte/Berberine interaction is responsible of fluorescence enhancement ion-induced dipole interactions Environment polarity modulates the fluorescence response

6 One molecule Its commercial standard Complex mixtures One molecule as standard? Detection method is chosen regarding to the structure of the molecules Response factor is generally structure dependent Preparative step based on TLC

7 S tandard P urification Example for the Fuel.5 ALKANES NAPHTHENES detection by UV detection by fluorescence AROMATICS Migration Preparative TLC Soxtec extraction Extract concentrated under N 2 until constant weight Purity checked Each fraction will be a standard GC-MS TLC NMR

8 Evaluation of evaporation losses during standard purification GC-FID of gas oil GC-FID of alkanes fraction 6 % for alkanes 1 % for aromatics

9 Middle Distillates Samples Straight-run run gas-oil ( C) 380 C) (Institut de Recherche sur la Catalyse,, Lyon) also submitted to hydrodesulfurization Light cycle oil (CEPSA, Madrid)

10 Petroleum Refining Process Gas-oil LCO

11 Chromatographic Parameters GAS OIL Alkanes Naphtenes Total aromatics PACs HPTLC plates silica gel impregnated with berberine silica gel silica gel impregnated with caffeine chromatographic conditions - 5 minutes with n-hexane - 5 minutes with n-hexane - 3 minutes with acetone - 5 minutes with n-hexan - 1 minute with acetone scanning densitometry detection Fluorescence UV at 254 nm Fluorescence

12 Analysis of the saturated compounds Fluorescence Scanning Densitometry 2.5 ALKANES Calibration Range : 0.05 to 1.5 µg y=1163x+744 R 2 = LOD = 0.05 µg LOQ = 0.15 µg Fluorescence (AU) 1,4 µg 1,2 µg 0,8 µg NAPHTHENES Gas oil H 3 CO OCH 3 N + O O Fluorescence responce (AU) Distance of migration 1,8 µg 1,4 µg 1,2 µg 0,8 µg -0.1 Calibration Range : 0.6 to 2.4 µg y=655x-89 R 2 = LOD = 0.1 µg LOQ = 0.3 µg Distance of migration (mm)

13 Total aromatics UV Scanning Densitometry UV Response (AU) 1.0 BaP Per Cor After the 2nd migration step Acetone Calibration Range : 0.1 to 2.0 µg y=873x+89 R 2 = LOD = 0.06 µg LOQ = 0.18 µg Distance of migration (mm)

14 Accuracy Standard Addition External Standard Percentage (m/m) determined by standard addition Percentage (m/m) determined by external standard (RSD%) LCO 57.7 % 57.5 % (4.3) GO 16.1 % 17.0 % (3.9) Preparation of Synthetic Fuel Theoretical value (%) Measured value (%) Recovered value (%) (RSD%) (6.5) (20.0) (10.0) (4.1) 90.1

15 Heavy aromatics (PACs) Plate impregnated with Caffeine : electron acceptor Response (AU) 0.20 Response 0.15 S S Fluorescence UV at 300 nm 0.00 UV at 300 nm Injection point Distance of migration (mm) 2nd migration step to merge P ACs Fluorescence scanning densitometry Distance of migration (mm) Selective detection and quantification of P ACs

16 Influence of Caffeine in the separation of aromatic Response UV Silica gel Fluorescence Response Caffeine stationary phase UV Fluorescence Distance of migration (mm) Distance of migration (mm)

17 Complete analysis of a Gas oil submitted to desulfurization % (M/M) Content of Sulfur 150 heavy PACs total aromatic cycloalkanes alkanes

18 S eparation of Aromatics according to the number of rings Paper Bridge Solvent Solvent Solvent Response S Response III rings IV and +IV rings I-II rings Distance of migration (mm) Distance of migration (mm)

19 Conclusions HPTLC is an interesting system for the analysis of complex samples Low cost Accurate Rapidity sensitive HPTLC coupled to UV and fluorescence scanning densitometry is a powerful tool Flexibility of development Applicable to a wide range of sample Suitable alternative to HPLC and other techniques utilized in HTA

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21 Identification of Naphthene fraction Response (AU) λexc = 365 nm λem = nm 210 nm 254 nm GC-FID counts Alkanes Naphthenes Distance of migration (mm) Naphthenes absorb at 210 nm IRFT min Chemical shifts and coupling constant typical of cyclic -CH2-1 H-NMR Increasing of the ratio CH2/CH3 (1459 cm cm-1)

22 INTEREST OF HPTLC FOR FOSSIL DERIVED PRODUCTS ANALYSIS : A SIMPLE APPROACH TO HYDROCARBON GROUP TYPE ANALYSIS Muriel Matt 1,2, Vicente L. Cebolla 1, Luis Membrado 1, Eva M. Galvez 1, Jesus Vela 1, Robert Bacaud 3 LTAC, Université de Metz. France Instituto de Carboquimica, CSIC, Zaragoza. Spain Institut de Recherches sur la Catalyse, CNRS, Lyon. France