GC MS Report

ANALYSIS THE CONTENT OF JARAK KEPYAR (RICINUS COMMUNIS, L.) BIODIESEL BY GAS CHROMATOGRAPHY MASS SPECTROPHOTOMETER (GC-MS)

Ni Kadek Wahyuni Antari (1213031002/A)

Chemistry Education Department, Faculty of Mathematics and Natural Sciences Universitas Pendidikan Ganesha

INTRODUCTION

Separation is an important process in the analytical procedures. Separation method that usually used to separate many complex component of mixture in little amount of sample is called chromatography. The basic principle of chromatography is separation method for complex components of mixture based on interaction of the components mixture with static phase and mobile phase. There are many types of chromatography; one of them is gas chromatography.

Gas chromatography is the components of vaporized sample are separated as a

consequence of being partitioned between a mobile gaseous phase and liquid or solid stationary phase held in the column. In performing a gas chromatographic separation, the sample is vaporized and injected into the head of a chromatographic column. Elution is brought about by the flow of an inert gaseous mobile phase. In contrast to most other type of chromatography, the mobile phase does not interact with molecules of the analyte, its only function is transport the analyte through the column [3]. There are two kinds of gas chromatography, such as gas- solid chromatography (GSC) and liquid-gas chromatography (GLC).

Liquid-gas chromatography based on partition of analyte between mobile phase (gas)

and stationary phase (liquid) mobilized on inert solid surface (Muderawan, 2009). Solid-gas chromatography (GSC) based on solid stationary phase whereas analyte retention occurred as consequence from adsorption physically by solid stationary phase. Solid-gas chromatography has limit application because of semi active molecule and polar molecule will strongly interact with stationary phase therefore tailing is occurred when the peak are eluted, as consequence from process adsorption non linier. This technique is used to separate gas molecule with low molecular molecule weight. Basic Principle of Gas Chromatography

The effectivity of coulomb chromatography in separating two solute substances depends on the relative rate of two elusion species. This rate is determined by equilibrium constant distribution of solute substance in mobile phase and stationary phase. Quantitatively, GC-MS data can be calculated by considering retention factor (migration rate of solute substance), selectivity factor (relative migration rate), coulomb efficiency and coulomb resolution. Retention factor Retention factor is an important parameter used for describing migration rate of solute

substance in coulomb. The retention factor of kA is as follow:

=

Selectivity Factor Selectivity factor of a coulomb for two species A and B is defined as the following equation:

=

Coulomb Efficiency

To find the number of N (plate number) can be used the following equation:

= 16 (

)2

Coulomb Resolution

Resolution column provide quantitatively measure the ability of the column to separate

analytes. Resolution column is defined as follows:

=2[() ()]

+

Gas chromatography can also be combined with a mass spectrometer, in this case the

mass spectrometer can be considered as a detector, known as the Gas Chromatography Mass Spectrometry (GC-MS). Gas Chromatography-Mass Spectrometry is analysis method based on chromatography by using detector of mass spectrometer. Result of the analysis is in form of chromatogram and mass spectrum of a compound. GC-MS analysis method is common used for determining composition of chemical of sample such as composition of crude oil, composition of pesticide in fruits, composition of cholesterol in plant oil and so on [1].

GC-MS is a combination of two different analytical techniques, Gas Chromatography

and Mass Spectrometry. GC-MS, with the use of internal standards, provides a multidimensional drug identification and quantitation procedure that is the leading confirmation method for forensic drug testing. Composition of methyl ester in biodiesel which is made from plant oil through transferification also can be determined by GC-MS. The purpose of this experiment is to determine methyl ester contained in biodiesel of Jarak Kepyar (Ricinus communis, L.) oil.

Castor (Ricinus communis L, Euphorbiaceae) is a versatile plant species. Castor bean has a

high oil rendemen, which could reach 56%. Castor oil contains fatty acids such as palmitic acid 1.3%, 5.5% oleic acid, linoelat acid 7.3%, 1.9% stearic acid, ricinoleic acid and 84% (Salimon in Sinarsih, 2010). All of the fatty acids contained in the castor oil is a long-chain of fatty acids. Generally the characteristic of castor oil can be seen on the picture below: Table 1. The Characteristic of Castor Oil

Characteristic Composition

Liquid condition Viscous Density 9.31 x 10-1 g/cm3

Saponification number 182.9 mg/g Fatty acid composition

Palmitate acid Oleic acid

Linoleic acid

1.3% 5.5% 7.3%

Linolenate acid Stearic acid

Ricinoleic acid

0.5% 1.2% 84.2%

Further research state that about 90% of the fatty acid content of castor oil is the triglyceride formed from ricinoleic acid. Ricinoleic acid (12-hydroxy-9-cis-octadecenoic acid) is unsaturated omega-9 fatty acid that naturally occurs in nature Castor plant (Ricinus communis L, Euphorbiaceae) seeds or in sclerotium of ergot (Claviceps purpurea Tul, Clavicipitaceae). Omega-9 fatty acid that naturally occurs in nature Castor plant (Ricinus communis L,

Euphorbiaceae) seeds or in sclerotium of ergot (Claviceps purpurea Tul, Clavicipitaceae). Ricinoleic acid is a viscous yellow liquid, with a melting point of < 100C and boiling point of 4160C at 760 mmHg. It is insoluble in water but soluble in most organic solvents. It is prepared by the hydrolysis of castor oil. It used in the textile finishing, in coating, inks and in making soaps [4]. Ricinoleic acid which is the greatest composition of castor oil is a unique fatty acid that is unique, because this fatty acid is oleic acid derivative in which has a hydroxyl group at = 12 and containing the bond at = 9. Ricinoleic acid having 18 carbon atoms with one hydroxyl group on the carbon atom number 12 and double bond at carbon number 9 and 10 with cis structure. Ricinoleic acid has molecular weight is 298.46. Due to the high content of ricinoleic acid in castor oil, it makes the castor oil has high hydroxyl group, iodine and saponification number compare to the other oil. Unlike other oils, castor oil mixed with alcohol and slightly soluble in petroleum ether at room temperature. (Naughton, 1973). Figure 1 shows the molecular structure of ricinoleic acid.

Figure 1. Structure of ricinoleic acid

The objectives of this experiment were to analyze the content of Jarak Kepyar (Ricinus communis L.) biodiesel from GC-MS data.

METHODS

The content of methyl ester in biodiesel made from jarak kepyar (Ricinus communis L.) oil was analyzed by GC-MS Agilent 6890N. The colum used was HP5-MS with length was 30 m and ID was 0,32 mm. The injector was setted at temperature of 260oC and the volume of sample was 1.0L. The temperature of oven was 260oC for 5 minutes and then increased 10oC/minutes until 270oC. It is then keep for 270oC for 5 minutes. The bringing gas was helium with flowing rate of 1 mL per minutes. The detector is MS (Mass spectrophotometer) [2].

RESULTS AND DISCUSSION

The content of methyl ester in biodiesel made from jarak kepyar (Ricinus communis L.) oil

was analyzed by GC-MS Agilent 6890N. The coloum used was HP5-MS with length was 30 m

and ID was 0,32 mm. The injector was setted at temperature of 260oC and the volume of sample

O

OH

OH

was 1.0L. The temperature of oven was 260oC for 5 minutes and then increased 10oC/minutes

until 270oC. It is then keep for 270oC for 5 minutes. The bringing gas was helium with flowing

rate of 1 mL per minutes. Then, the result of GC-MS of jarak kepyar biodiesel can be seen as

follows.

Figure 3. Chromatogram of Jarak Kepyar Biodiesel

The percentage of compound in jarak kepyar biodiesel was calculated by following equation.

% =

100%

The percentage of compound in jarak kepyar biodiesel was calculated in the following table.

Table 2. Result of Chromatogram Analysis Biodiesel Jarak Kepyar

No RT Area Compound Molecular

Formula

Mr

(g/mole)

% Rs

1 19.94 2.17 Methyl hexadecanoate C17H34O2 270 2.17%

2 21.58 8.61 Methyl 9, 12-

octadecadienoate

C19H34O2 294 8.61% 9.316

3 21.63 7.65 Methyl 9-octadecenoate C19H36O2 296 7.65% 0.211

4 21.68 1.35 Methyl 11-

octadecenoate

C19H36O2 296 1.35% 0.252

5 21.84 2.11 Methyl octadecanoate C19H36O2 296 2.11% 0.833

6 23.38 77.57 Methyl 12-hydroxy-9-

octadecenoate

C19H36O3 312 77.57% 4.438

7 23.60 0.44 Methyl eicosanoate C21H42O2 326 0.44% 0.489

8 24.99 0.10 Not identified - - 0.10% 5.148

= 100 = 100%

The molecular structures of each compound in Jarak Kepyar biodiesel were as follow:

1. Methyl Hexadecanoate

CH3O

O

CH3

2. Methyl 9, 12-Octadecadienoate

CH3O

O

CH3

3. Methyl 9-Octadecenoate

CH3O

O

CH3

4. Methyl 11-Octadecenoate

CH3O

O

CH3

5. Methyl Octadecanoate

CH3O

O

CH3

6. Methyl 12-hydroxy-9-Octadecenoate

CH3

OH

O

OCH3

7. Methyl Eicosanoate

O

O

CH3CH3

Figure 4.The molecular structure of each component of Jarak Kepyar

Figure 5. The mass spectrums of component in Jarak Kepyar Biodiesel with retention time of 23.38 minutes

Then, the fragmentation of methyl ester with retention time 23.38 minutes in order to prove the

molecular structure of methyl 12-hydroxy-9-octadecenoate as follows.

HO

O

O

Fragmentasi methyl 12-hydroxy-9-octadecenoate (Part 1)

O

O

- H2O (18)

- CH3 (15)

m/e=279

m/e=294

m/e=312

O

O


- CH4 (16)

- CH6 (18)

m/e=245

m/e=263

m/e=279

O

O

O

O

O

O


- H2O (18)

- OCH (29)

m/e=198

m/e=227

m/e=245

O

O

O


- C2H8 (32)

- CH6 (18)

m/e=148

m/e=166

m/e=198

m/e=137

- C2H5 (29)


- CH(13)

- CH2 (14)

m/e=110

m/e=124m/e=137


O

- C16H16OH(225)

m/e=87

H3C

HO

O

O

CH3

m/e=312

CH3

O

O

m/e=74

CH3

O

- CH(13)


- CH(13)

m/e=97m/e=110

- C3H6 (42)

m/e=55

- CH2 (14)

m/e=41m/e=29

- C(12)- CH2(14)

CH3

m/e=15

Figure 6. Fragmentation of methyl 12-hydroxy-9-octadecenoate

CONCLUSIONS

Based on the result and discussion above, it can be concluded that Jarak Kepyar (Ricinus communis, L.) biodiesel contains of eight compounds, namely: methyl hexadecanoate, methyl 9,12-octadecadienoate, methyl 9-octadecenoate, methyl 11-octadecenoate, methyl octadecanoate, methyl 12-hydroxy-9-octadecenoate, methyl eicosanoate. Then, the main compound was methyl 12-hydroxy-9-octadecenoate that has retention time of 23.38 minutes and its percentage was 77.57%.

REFERENCES

1. Muderawan, I. W. 2009. Analisis Instrumen. Undiksha Press: Singaraja. 2. Muderawan, I. W. Jurnal Praktikum Analisis Kimia Instrumen. 3. Pertiwi, L. L. 2013. Purification of Ricinoleic Acod from Castor Oil by Column Chromatography.

Thesis. 4. Sinarsih, K. 2012. Penentuan Waktu OptimumTransesterifikasi dan Komposisi Methyl Ester

Penyusunan Biodiesel Minyak Jarak Kepyar (Ricinicus Communis L.). Skripsi.

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GC MS Report