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Polycyclic aromatic hydrocarbons ( PAHs ) are besides known as polynuclear aromatic hydrocarbons or poly-aromatic hydrocarbons. They consist of fused aromatic rings and do non incorporate heteroatoms or substituents. The pure PAHs are normally in colourless, white or pale xanthous green coloring material solids. These compounds have their major beginnings in dodo or man-made fuels or are produced as by merchandises from the uncomplete burning or high-temperature reactions of coal, oil and gas, car fumes every bit good as organic stuffs. Furthermore, uncomplete burning of fuel in an internal burning engine non merely causes the formation of PAHs, other gaseous and particulates will besides be emitted. A few PAHs can be used in medical specialties and some can be used to do plastics, pesticides, dyes and so on.

Presents, PAHs is one of the largest groups of environmental carcinogens which are present in air, nutrient and imbibing H2O. As the by-products of debasement and burning of organic stuffs, PAHs has become widespread in the environment. They are pollutants which are carcinogenic, teratogenic and mutagenic. The United State Environment Protection Agency ( EPA ) has selected 32 compounds of PAHs to be chief pollutants. Among these 32 PAHs compounds, the EPA has categorised seven PAH compounds to be the possible carcinogens which can impact human wellness which are benzo ( a ) anthracene, chrysene, benzo ( a ) pyrene, benzo ( B ) fluoranthene, benzo ( K ) fluoranthene, dibenz ( a, H ) anthracene and indeno ( 1,2,3-cd ) pyrene. Therefore, to avoid these 7 PAHs compounds exist overly in the environment and endanger human ‘s wellness, the presence of PAHs has to be monitored on a regular basis in the most environmental section and industrial concern. The rule of this undertaking is to find the concentration of these 7 PAH compounds present in motor oil samples which are from the auto mill and so place whether they are within the bound set by the Department of Environment ( DOE ) . If the concentration of the 7 PAHs in the waste oil exceeds the bound, the waste oil has to be treated before being disposed. Besides that, any penalty may besides be given to the proprietor. Used motor oils which contain PAHs are mutagenic ; particularly from the motor vehicles which utilizing leaded gasoline whereas used oils from vehicles which utilizing leadless gasoline or Diesel fuel are less mutagenic. Since the method used is considered as a new method which is imported from other state. Thus, I was given a opportunity to partly formalize the method whether the recoveries of sample analytes can be obtained through this method.

PAHs are lipotropic, so they are easier to blend with oil instead than H2O. Therefore, PAHs are largely present in dirt and oily substances in the environment when they are in larger sizes, but sometimes, they besides exist in particulate affairs which suspended in the air. PAHs in the dirt can flux into belowground H2O and so pollute the H2O. Furthermore, PAHs can besides come in into H2O through discharges from intervention workss of industrial and sewage H2O. However, most of the PAHs are non soluble in H2O, so they prefer uniting with solid atoms and so settle to the underside of rivers and exist in deposit. Sediments, dirts, H2O and other substances will be contaminated when PAHs is present. After a period of hebdomads or months, PAHs can be broken down by micro-organisms, so they will non be everlastingly.

Toxicity of PAHs depends on the constructions but non on their sizes. With isomers, they can be from non toxic to highly toxic. Although some effects of PAHs have non been seen in human so far, carnal experiments have proved that PAHs are really carcinogenic. After exposing to the PAHs no affair for a short or long period of clip, they can do harmful wellness effects such as on the tegument, organic structure fluids, and besides the ability to contend diseases. For case, research lab animate beings were infected by tegument malignant neoplastic disease when their tegument were exposed to the PAHs for a long clip, lung malignant neoplastic disease when they breathed air which incorporating PAHs every bit good as tummy malignant neoplastic disease when they consumed nutrient incorporating PAHs. Furthermore, in the carnal surveies on mice, the mice which were injected high degree of benzo ( a ) pyrene during gestation would happen troubles when reproducing. Besides that, their progeny besides had higher chance of birth defects, decreased organic structure weights and IQ if they extremely exposed to the benzo ( a ) pyrene before being given birth. These effects may besides happen in human. Fortunately, most of the PAHs which enter the organic structure will go forth through fecal matters and piss within a few yearss.

The undermentioned seven constructions are the seven PAHs which are the possible carcinogens of human existences and they are the mark analytes of this undertaking:

Properties of Polycyclic Aromatic Hydrocarbon

IUPAC Name

Molecular Structure

Molecular Formula

Appearance

Carcinogenicity

Beginnings

Benzo ( a ) anthracene

C18H12

Solid

Carcinogenic

Mineral oil

Benzo ( B ) fluorenthene

C20H12

Whitish to tan pulverization

Strongly carcinogenic

Oysters

Benzo ( K ) fluorenthene

C20H12

Pale xanthous solid ( acerate leafs )

Not carcinogenic

Oysters

Roasted Coffee

Benzo ( a ) pyrene

C20H12

Pale yellow solid

Strongly carcinogenic

Smoked nutrients

Oysters

Cigarettes

Oils

BBQ beef & A ; porc

Wax

Charcoal-broiled steaks

Roasted java

Contaminated H2O

Fruits and veggies

Chrysene

C18H12

Colourless with bluish or red-blue fluorescence orthorhombic bipyramidal home bases

Carcinogenic

Oysters

Wax

Smoked nutrients

Roasted java

Dibenz ( a, H ) anthracene

C22H14

Colourless solid

Strongly carcinogenic

Charcoal-broiled steaks

Indeno ( 1,2,3-cd ) pyrene

C22H12

Yellow home bases

Carcinogenic

Own work

3.3.2 Surrogate

Surrogate is a pure analyte which is non possible to be found in any samples, but its feature is the same as the sample analytes, so that there is no imbrication of keeping clip between the alternate and any sample analytes. Surrogate solution with known concentration is added into the sample prior to extraction and any other procedures. After that, it is determined by utilizing the same processs which are used to mensurate the sample analytes, and so its recovery is measured. The map of the alternate is to supervise the method public presentation of with each sample. Individual alternate recoveries are used to rectify the concentrations of specific analyte harmonizing to the keeping clip. The alternate used in this undertaking is terphenyl-d14.

3.3.3 Internal Standard

An internal criterion is a pure analyte with known concentration and different from sample analyte. It is added into a sample, infusion or standard solution. The map of internal criterion is to mensurate the comparative response or concentration of other method analytes and alternates which are constituents of the same solution with it by comparing the signal from analyte with the signal from the internal criterion.

Internal criterion is really utile for analyzing a sample in which the sample ‘s measure or the response of instrument will somewhat change from tally to run. The right concentration of analyte can be derived, merely if the concentration of internal criterion is known. Besides that, internal criterion is normally used in the chromatography because the small sum of sample solution which is injected into the chromatograph is non really consistent in some trials. In this undertaking, perylene-d12 is used as internal criterion to cipher the concentration of other unknown analytes.

3.4 Principle of Method:

Samples are made up in solution, spiked with alternate ( terphenyl-d14 ) , and so transferred into a silica gel clean-up column. By elution with hexane and dichloromethane/hexane 1:1, samples are fractionated into saturate fractions ( F1 ) and aromatic fractions ( F2 ) . Then, both fractions are concentrated by vaporization under dry N “ blow-down ” setup. The seven compounds of PAHs are in the aromatic fractions ( F2 ) whereas saturate fractions ( F1 ) contains concentrated hydrocarbon. For the intent of finding of PAHs, aromatic fraction ( F2 ) is spiked with internal criterion ( perylene-d12 ) , accurately exceed up to the pre-injection volume and so analyzed by GC/MS in the scan manner.

3.5 Apparatus and Reagent:

3.5.1 Apparatus:

Analytic balance – must be able to accurately weigh 0.0001g

Volumetric flasks – 1mL, 5mL and 10mL

Volumetric flasks must be rinsed with three parts each of DCM/hexane 1:1 and hexane in turn before usage.

Graduated cylinders – 5mL, 10mL and 20mL

Micropipettes – 10AµL-1000AµL

Sample clean-up column – 300mm long x 10.5mm internal diameter plugged with glass wool at the underside and a Teflon turncock. Fritted spectacless phonograph records are non recommended because they will be really hard to be cleaned after high concentration of infusions have been passed through.

15mL Centrifuge tubes – calibrated, graduated and with ground-glass stopper

Centrifuge tubing and its stopper must be rinsed with three parts each of DCM/hexane 1:1 and hexane in turn before usage.

Dry-nitrogen “ blow-down ” device

Phials – 1mL, with Teflon-lined prison guard cap septa

Funnels

Gas chromatograph with mass spectrometer ( GC/MS )

GC column used for analysis is 30m long x 0.25mm internal diameter, 60oC-325oC temperature bound, 0.25Aµm movie thickness capillary DB-5MS ( Durabond-5 Mass Spectrum ) .

Note: All glasswork has to be rinsed with dissolver ( DCM and hexane ) before being used.

3.5.2 Reagents:

Acetone

Methylene chloride

Dichloromethane ( DCM ) /hexane 1:1

Hexane

Glass wool

Before usage, glass wool is placed into a big pre-cleaned column. Then, it is eluted with 2 volume of column of DCM followed by 2 volume of column of hexane. DCM and hexane are so discarded. A beaker is pre-cleaned with DCM and hexane. The clean cotton wool is poured into the beaker, covered slackly with solvent-rinsed aluminium foil. It is so dried overnight in fume goon. After that, the cotton wool is stored in an oven at temperature runing from 160-200oC until ready for usage.

Silica gel

– Before usage, it must be serially rinsed with propanone, DCM and hexane, so wholly dried at 50oC followed by activation for at least 20 hours at 160-180oC in a shallow glass tray, slackly covered with foil.

Anhydrous Na sulfate

Before usage, Na sulfate must be cleaned by utilizing dissolver. The Na sulfate is poured into a pre-cleaned column. Then, it is eluted with 2 volume of column of DCM followed by 2 volume of column of hexane. DCM and hexane are so discarded. A beaker is pre-cleaned with DCM and hexane. The clean Na sulfate is poured into the beaker, covered slackly with solvent-rinsed aluminium foil. It is so dried overnight in fume goon. After that, the Na sulfate is dried in an oven at about 180oC nightlong. Sodium sulfate is stored in an oven at temperature runing from 180A±20oC until ready for usage.

PAH stock mix standard solution – 1000ppm

Internal criterions – Perylene-d12 – 1000ppm

Surrogate – Terphenyl-d14 – 1000ppm

3.6 Procedures:

3.6.1 Preparation of Internal Standard ( Perylene-d12 ) and Surrogate ( Terphenyl-d14 )

The stock internal criterion and alternate solutions which are 1000ppm were diluted with hexane into 100ppm severally.

Then, the 100ppm of internal criterion and foster solutions was farther diluted into the other concentration that was required in the undermentioned stairss.

3.6.2 Calibration

Calibration criterions were prepared from the 1000ppm of PAH stock mix standard solution.

1000ppm of the PAH stock mix standard solution was diluted with hexane to 5ppm, 10ppm, 20ppm, 50ppm and 100ppm in 1mL volumetric flask.

The five volumetric flasks with different concentration of mix criterion were spiked with alternate with the concentrations which are same as their several mix criterion.

Then, each of the volumetric flasks was spiked with 0.2mL of 100ppm of internal criterion to do the concentration of internal criterion to be 20ppm.

Hexane was added to the standardization grade and so the 5 solutions were transferred into 5 different of 1mL phials.

After that, the 5 standardization criterions were analyzed by GC/MS in the scan manner. The status of GC/MS will be indicated at Section3.6.3 ( C ) .

The standardization graphs of 7 PAHs compounds and alternate were printed out and the one-dimensionality of graphs were determined.

3.6.3 Determination of PAHs in waste oil samples

( A ) Waste Oil Sample readying

Sample with alternate but without mix criterion ( Mixture of 7 compounds PAHs )

0.5000g of waste oil sample was weighed and pipette into a 5mL volumetric flask.

Surrogate was spiked into the volumetric flask.

Then, hexane was added to the standardization grade.

The volumetric flask was shaked smartly.

Sample with alternate and blend criterion ( Mixture of 7 compounds PAHs )

0.5000g of waste oil sample was weighed and pipette into a 5mL volumetric flask.

Surrogate followed by mix criterion were spiked into the volumetric flask.

Then, hexane was added to the standardization grade.

The volumetric flask was shaked smartly.

( B ) Sample Cleanup

A 0.5cm bed of cotton wool was placed into a 300mm long, 10.5mm internal diameter of chromatographic column.

Approximately 3g of activated silicon oxide gel was so placed into the column.

The column was tapped gently to settle the silicon oxide gel.

A 0.5cm bed of anhydrous Na sulfate was added on the top of silica gel.

The column was preconditioned with 20mL of hexane, the eluent was discarded.

When hexane has drained to the top of the column bed, 500AµL of concentrated sample and 3mL of hexane were transferred into the column. 3mL of eluent was so discarded.

Before sodium sulfate exposed to the air, 12mL of hexane was added into the column. This eluent was collected in a graduated and calibrated extractor tubing and this fraction was labeled as “ F1 ” .

Before sodium sulfate exposed to the air, 15mL of DCM/hexane 1:1 was added into the column. The eluent was so collected in another calibrated and graduated extractor tubing and this fraction was labeled as “ F2 ” .

After that, both fractions were concentrated gently to about volumes of 0.6-0.8mL by vaporization under dry N in the “ blow-down ” setup.

The concentrated fractions were spiked with 2mL of 100ppm of internal criterion to do the internal criterion to be 20ppm.

Both fractions were topped up to the pre-injection volume of 1 A± 0.1mL and so transferred into 1mL of phials with decently labeled Teflon-lined prison guard cap septa. Phials should be instantly closed to avoid vaporization of dissolver. The fractions have to be stored refrigerated, in the dark, for later analysis.

( C ) Determination of PAHs by GC/MS

The seven compounds of PAHs were analyzed by GC/MS in the scan manner.

The selected characteristic ions used for analysis of PAHs are listed in the Appendix.

The operating conditions of GC/MS are the undermentioned:

Mass scope: 35-500amu

Scan clip: 1sec/scan

Initial temperature: 40oC, clasp for 4 proceedingss

Temperature plan: 40-270oC at 10oC/min

Concluding temperature: 300oC, hold about 15 proceedingss until all compounds elute

Injector temperature: 250-300oC

Transportation line temperature: 250-300oC

Injector: splitless ( usually for low concentration of analyte )

Injection volume: 1AµL

Carrier gas: He at 30cm/sec

After that, the consequences were printed out and analyzed.

3.6.4 Quality Control ( QC ) Protocol

Mid flat concentration of standardization criterions which is 20ppm of PAH stock mix standard solution, spiked with 20ppm of internal criterion was analyzed by GC/MS in the scan manner. This is used to look into the public presentation of instrument. QC has to be analyzed after each 10 samples are run to guarantee that samples are running within the instrument public presentation.

3.7 Consequences and Calculation:

Calculation for the volumes of 1000ppm of stock mix standard solution used to fix 5ppm, 10ppm, 20ppm, 50ppm and 100ppm of mix standard solution:

By utilizing expression,

M1V1=M2V2

For 5ppm, M1V1=M2V2

1000ppm ten V1 = 5ppm x 1mL

V1 = 0.005mL

For 10ppm, 1000ppm ten V2 = 10ppm ten 1mL

V2 = 0.01mL

For 20ppm, 1000ppm ten V3 = 20ppm ten 1mL

V3 = 0.02mL

For 50ppm, 1000ppm ten V4 = 50ppm ten 1mL

V4 = 0.05mL

For 100ppm, 1000ppm ten V5 = 100ppm ten 1mL

V2 = 0.1mL

Calculation for the volume of alternate used in the sample readying

For illustration, 20ppm of alternate was spiked into the sample,

To avoid overloading, no more than 50mg of oil can be placed on the column.

Therefore, we decided to put 50mg of oil on the column. This is because we can salvage the sum of alternate ‘s stock solution used.

Concentration of oil = mass of sample used / volume of solution

=

= 100000 mg/L

1 L: 100000mg where ten be the volume of concentrated sample which is ten L: 50mg spiked into the column

ten =

= 5 ten 10-4 L

= 500AµL

So, to avoid overloading, the maximal volume of concentrated sample can be spiked into the column is 500AµL.

M1V1=M2V2

M1 x 500AµL = 20ppm x 1mL

M1 = 40ppm

M3V3=M4V4

100 ten V3 = 40ppm x 5mL

V3 = 2mL

Where M1 = M4 = Concentration of sample

M2 = Concentration of alternate obtained after sample killing

M3 = Concentration alternate ‘s stock solution ( 100ppm )

V1 = Volume of concentrated sample spiked into column

V2 = Pre-injection volume

V3 = Volume of alternate ‘s stock solution used

V4 = Volume of sample solution prepared

Therefore, 2mL of alternate was used in the sample readying to do a concentration of 20ppm.

Note: To cipher other concentration of alternate and blend criterion spiked into the sample, the same computation stairss are used.

3.7.1 Calibration

The standardization graphs are attached behind.

3.7.1.1 Calculation of Relative Response Factor ( RRF ) for each analyte in the standardization mixtures at each of the concentration degrees

Relative Response Factors, RRF =

Where:

As = Area for the mark analyte to be measured

AIS = Area for the internal criterion ( IS )

CIS = Concentration of the internal criterion ( 20ppm )

Cs = Concentration of the mark analyte

The values of As, AIS and Cs can be referred to the quantitation study attached behind.

Table 3.1: Relative Response Factor for 5ppm mix standard

Name of compound

As ( x106 )

Army intelligence

( x106 )

Commonwealth of independent states

Cesium

RRF

Terphenyl-d14

7.1

30.9

20

4.41

1.042057

Benz ( a ) anthracene

7.3

30.9

20

3.71

1.273563

Chrysene

6.5

30.9

20

3.58

1.175173

Benzo ( B ) fluorenthene

5.3

30.9

20

2.47

1.388834

Benzo ( K ) fluorenthene

10.4

30.9

20

4.5

1.495865

Benzo ( a ) pyrene

4.5

30.9

20

2.16

1.348436

Indeno ( 1,2,3-cd ) pyrene

6.1

30.9

20

4.9

0.805759

Dibenzo ( a.h ) anthracene

4.9

30.9

20

3.5

0.906149

Table 3.2: Relative Response Factor for 10ppm mix standard

Name of compound

As

( x106 )

Army intelligence

( x106 )

Commonwealth of independent states

Cesium

RRF

Terphenyl-d14

18.5

42.1

20

11.42

0.76958

Benz ( a ) anthracene

19.3

42.1

20

9.75

0.940374

Chrysene

19.9

42.1

20

10.85

0.871307

Benzo ( B ) fluorenthene

18.2

42.1

20

8.41

1.028071

Benzo ( K ) fluorenthene

27.2

42.1

20

11.73

1.101587

Benzo ( a ) pyrene

17.1

42.1

20

8.1

1.002903

Indeno ( 1,2,3-cd ) pyrene

17.1

42.1

20

10.06

0.807507

Dibenzo ( a.h ) anthracene

14.5

42.1

20

7.56

0.911159

Table 3.3: Relative Response Factor for 20ppm mix standard

Name of compound

As

( x106 )

Army intelligence

( x106 )

Commonwealth of independent states

Cesium

RRF

Terphenyl-d14

30.5

41.4

20

18.81

0.783323

Benz ( a ) anthracene

39.2

41.4

20

19.81

0.955941

Chrysene

39

41.4

20

21.25

0.886616

Benzo ( B ) fluorenthene

40.2

41.4

20

18.53

1.048046

Benzo ( K ) fluorenthene

49.1

41.4

20

21.14

1.122034

Benzo ( a ) pyrene

37.1

41.4

20

17.56

1.020655

Indeno ( 1,2,3-cd ) pyrene

20.3

41.4

20

12.17

0.805815

Dibenzo ( a.h ) anthracene

30.3

41.4

20

16.01

0.914284

Table 3.4: Relative Response Factor for 50ppm mix standard

Name of compound

As

( x106 )

Army intelligence

( x106 )

Commonwealth of independent states

Cesium

RRF

Terphenyl-d14

92.3

44

20

56.89

0.737468

Benz ( a ) anthracene

91.4

44

20

46.14

0.900422

Chrysene

91.4

44

20

49.79

0.834414

Benzo ( B ) fluorenthene

106.5

44

20

49.08

0.98633

Benzo ( K ) fluorenthene

142.1

44

20

61.13

1.056616

Benzo ( a ) pyrene

93.7

44

20

44.3

0.96142

Indeno ( 1,2,3-cd ) pyrene

83.4

44

20

46.94

0.807607

Dibenzo ( a.h ) anthracene

105.7

44

20

52.54

0.914455

Table 3.5: Relative Response Factor for 100ppm mix standard

Name of compound

As

( x106 )

Army intelligence

( x106 )

Commonwealth of independent states

Cesium

RRF

Terphenyl-d14

156.9

43.4

20

96.68

0.747871

Benz ( a ) anthracene

202.2

43.4

20

102.06

0.91299

Chrysene

183.4

43.4

20

99.84

0.846516

Benzo ( B ) fluorenthene

219.3

43.4

20

101.04

1.000197

Benzo ( K ) fluorenthene

218.7

43.4

20

94.06

1.07148

Benzo ( a ) pyrene

219.3

43.4

20

103.67

0.974823

Indeno ( 1,2,3-cd ) pyrene

180.9

43.4

20

103.1

0.808575

Dibenzo ( a.h ) anthracene

198.3

43.4

20

99.85

0.915198

3.7.1.2 Percent comparative criterion divergence ( % RSD ) for the five RRFs for each analyte

% RSD

=

Standard divergence of the RRFs

Average of the RRFs

X 100 %

Standard divergence =

Where eleven = each RRF value used to cipher the mean RRF

= the mean of N values

n = entire figure of values = 5

All informations is referred to the quantitation study attached behind.

Table 3.6: Percentage comparative criterion divergence ( % RSD ) for the 5 RRFs for each analyte

Name of compound

Relative Response Factor

Average

Standard Deviation

% RSD

5 ppm

10 ppm

20 ppm

50 ppm

100 ppm

Terphenyl-d14

1.042057

0.769580

0.783323

0.737468

0.747871

0.816060

0.12760581

15.64

Benz ( a ) anthracene

1.273563

0.940374

0.955941

0.900422

0.912990

0.996658

0.156336095

15.69

Chrysene

1.175173

0.871307

0.886616

0.834414

0.846516

0.922805

0.142552036

15.45

Benzo ( B )

fluorenthene

1.388834

1.028071

1.048046

0.986330

1.000197

1.090296

0.168603741

15.46

Benzo ( K )

fluorenthene

1.495865

1.101587

1.122034

1.056616

1.07148

1.169516

0.184207691

15.75

Benzo ( a ) pyrene

1.348436

1.002903

1.020655

0.96142

0.974823

1.061647

0.161989879

15.26

Indeno ( 1,2,3-cd )

pyrene

0.805759

0.807507

0.805815

0.807607

0.808575

0.807053

0.001228422

0.15

Dibenzo ( a.h )

anthracene

0.906149

0.911159

0.914284

0.914455

0.915198

0.912249

0.00374513

0.41

3.7.2 Verification of Calculation for PAHs

Concentration of the analyte of involvement in the sample ( Aµg/g ) =

Where:

As = Area for the analyte in the sample

AIS = Area for the internal criterion ( IS )

WIS = Amount of internal criterion added to the sample = 20Aµg

D = Dilution factor ( dimensionless ) = 5

Ws = Weight of sample ( g )

Table 3.7: Calculation of Concentration for 7 PAH in sample waste W

( no alternate spiked and without sample clean-up ) 26 Jun 2010

Name of compound

Area for the mark analyte

( x106 )

Area of IS

( x106 )

Conc. of IS ( ppm )

Conc. of mark analyte ( ppm )

RRF

Conc. ( Aµg/g )

DOE bound ( ug/g )

Terphenyl-d14

0.04

12

20

0.03

2.222222222

0.3

Benz ( a ) anthracene

3.9

12

20

1.99

3.266331658

19.9

100

Chrysene

4

12

20

2.22

3.003003003

22.2

100

Benzo ( B ) fluorenthene

1.4

12

20

0.68

3.431372549

6.8

100

Benzo ( K ) fluorenthene

1.4

12

20

0.61

3.825136612

6.1

100

Benzo ( a ) pyrene

1.4

12

20

0.71

3.286384977

7.1

10

Indeno ( 1,2,3-cd ) pyrene

1.3

12

20

2.69

0.805452292

26.9

100

Dibenzo ( a.h ) anthracene

0.1

12

20

0.21

0.793650794

2.1

10

Table 3.8: Calculation of Concentration for 7 PAHs in sample waste A

( no alternate spiked and without sample clean-up ) 25 Jun 2010

Name of compound

Area for the mark analyte

( x106 )

Area of IS

( x106 )

Conc. of IS ( ppm )

Conc. of mark analyte ( ppm )

RRF

Conc. ( Aµg/g )

DOE bound ( ug/g )

Terphenyl-d14

0.07

37.7

20

0.05

0.74270557

0.5

Benz ( a ) anthracene

0.2

37.7

20

0.11

0.964552689

1.1

100

Chrysene

0.1

37.7

20

0.1

0.530503979

1

100

Benzo ( B ) fluorenthene

0.08

37.7

20

0.04

1.061007958

0.4

100

Benzo ( K ) fluorenthene

0.09

37.7

20

0.04

1.193633952

0.4

100

Benzo ( a ) pyrene

0.1

37.7

20

0.05

1.061007958

0.5

10

Indeno ( 1,2,3-cd ) pyrene

0.01

37.7

20

0.01

0.530503979

0.1

100

Dibenzo ( a.h ) anthracene

0.05

37.7

20

0.03

0.884173298

0.3

10

Table 3.9: Calculation of Concentration for 7 PAHs in waste W1

( 20ppm alternate spiked and with sample clean-up ) 28 Jun 2010

Name of compound

Area for the mark analyte

( x106 )

Area of IS

( x106 )

Conc. of IS ( ppm )

Conc. of mark analytev ( ppm )

RRF

Conc. ( Aµg/g )

DOE bound ( ug/g )

Terphenyl-d14

74.3

44

20

45.81

0.737234824

458.1

Benz ( a ) anthracene

3.9

44

20

2

0.886363636

20

100

Chrysene

2.4

44

20

1.32

0.826446281

13.2

100

Benzo ( B ) fluorenthene

2.9

44

20

1.35

0.976430976

13.5

100

Benzo ( K ) fluorenthene

2.8

44

20

1.25

1.018181818

12.5

100

Benzo ( a ) pyrene

2.9

44

20

1.4

0.941558442

14

10

Indeno ( 1,2,3-cd ) pyrene

1.2

44

20

0.7

0.779220779

7

100

Dibenzo ( a.h ) anthracene

0.1

44

20

0.07

0.649350649

0.7

10

Table 3.10: Calculation of Concentration for 7 PAHs in waste W2

( 20ppm alternate spiked and with sample clean-up ) 30 Jun 2010

Name of compound

Area for the mark analyte

( x106 )

Area of IS

( x106 )

Conc. of IS ( ppm )

Conc. of mark analyte ( ppm )

RRF

Conc. ( Aµg/g )

DOE bound ( ug/g )

Terphenyl-d14

14.3

13.2

20

8.92

2.428998505

89.2

Benz ( a ) anthracene

0.8

13.2

20

0.43

2.81888654

4.3

100

Chrysene

0.4

13.2

20

0.26

2.331002331

2.6

100

Benzo ( B ) fluorenthene

0.3

13.2

20

0.16

2.840909091

1.6

100

Benzo ( K ) fluorenthene

0.5

13.2

20

0.24

3.156565657

2.4

100

Benzo ( a ) pyrene

0.4

13.2

20

0.23

2.635046113

2.3

10

Indeno ( 1,2,3-cd ) pyrene

0.2

13.2

20

0.51

0.594177065

5.1

100

Dibenzo ( a.h ) anthracene

0

13.2

20

0

0

0

10

Table 3.11: Calculation of Concentration for 7 PAHs in waste A1

( 20ppm alternate spiked and with sample clean-up ) 28 Jun 2010

Name of compound

Area for the mark analyte

( x106 )

Area of IS

( x106 )

Conc. of IS ( ppm )

Conc. of mark analyte ( ppm )

RRF

Conc. ( Aµg/g )

DOE bound ( ug/g )

Terphenyl-d14

46.3

39

20

28.53

0.832232378

285.3

Benz ( a ) anthracene

0.05

39

20

0.03

0.854700855

0.3

100

Chrysene

0.06

39

20

0.04

0.769230769

0.4

100

Benzo ( B ) fluorenthene

0.02

39

20

0.01

1.025641026

0.1

100

Benzo ( K ) fluorenthene

-0.002

39

20

0

0

0

100

Benzo ( a ) pyrene

0.1

39

20

0.06

0.854700855

0.6

10

Indeno ( 1,2,3-cd ) pyrene

0

39

20

0

0

0

100

Dibenzo ( a.h ) anthracene

0

39

20

0

0

0

10

Table 3.12: Calculation of Concentration for 7 PAHs in waste A2

( 20ppm alternate spiked and with sample clean-up ) 30 Jun 2010

Name of compound

Area for the mark analyte

( x105 )

Area of IS

( x105 )

Conc. of IS ( ppm )

Conc. of mark analyte ( ppm )

RRF

Conc. ( Aµg/g )

DOE bound ( ug/g )

Terphenyl-d14

423.2

360.1

20

26.38

0.891000078

263.8

Benz ( a ) anthracene

0.3

360.1

20

0.02

0.833101916

0.2

100

Chrysene

0.3

360.1

20

0.02

0.833101916

0.2

100

Benzo ( B ) fluorenthene

0

360.1

20

0

0

0

100

Benzo ( K ) fluorenthene

0.1

360.1

20

0.01

0.555401277

0.1

100

Benzo ( a ) pyrene

1

360.1

20

0.05

1.110802555

0.5

10

Indeno ( 1,2,3-cd ) pyrene

0

360.1

20

0

0

0

100

Dibenzo ( a.h ) anthracene

0

360.1

20

0

0

0

10

Note: The concentrations of analytes which are non noticeable are assumed as nothing.

3.7.3 Determination of the Sample Recovery

Concentration of mark analyte in the mix criterion

= Concentration of mark analyte – Concentration of mark analyte in the space

Recovery per centum of mix criterion =

Concentration of mark analyte in the mix criterion

Concentration of mix criterion spiked

x 100 %

Table 3.13: Calculation of recovery per centum of mix criterion for waste W1+ 10ppm mix criterion ( 20ppm alternate through column ) 30 Jun 2010

Name of compound

Concentration of mark analyte ( ppm )

Concentration of mark analyte in the space ( ppm )

Concentration of mark analyte in the mix criterion ( ppm )

Recovery per centum of mix criterion ( % )

Terphenyl-d14

26.24

0.03

26.21

131.05

Benz ( a ) anthracene

13.34

1.99

11.35

113.50

Chrysene

11.53

2.22

9.31

93.10

Benzo ( B ) fluorenthene

10.36

0.68

9.68

96.80

Benzo ( K ) fluorenthene

11.78

0.61

11.17

111.70

Benzo ( a ) pyrene

10.11

0.71

9.4

94.00

Indeno ( 1,2,3-cd ) pyrene

4.34

2.69

1.65

16.50

Dibenzo ( a.h ) anthracene

4.47

0.21

4.26

42.60

Table 3.14: Calculation of recovery per centum of mix criterion for waste W2 + 10ppm mix criterion ( 20ppm alternate through column ) 1 July 2010

Name of compound

Concentration of mark analyte ( ppm )

Concentration of mark analyte in the space ( ppm )

Concentration of mark analyte in the mix criterion ( ppm )

Recovery per centum of mix criterion ( % )

Terphenyl-d14

43.16

0.03

43.13

215.65

Benz ( a ) anthracene

12.84

1.99

10.85

108.50

Chrysene

12.24

2.22

10.02

100.20

Benzo ( B ) fluorenthene

10.81

0.68

10.13

101.30

Benzo ( K ) fluorenthene

11.66

0.61

11.05

110.50

Benzo ( a ) pyrene

10.42

0.71

9.71

97.10

Indeno ( 1,2,3-cd ) pyrene

6.96

2.69

4.27

42.70

Dibenzo ( a.h ) anthracene

6.72

0.21

6.51

65.10

Note: The concentration of mark analyte in the space of waste W is taken from the concentration of mark analyte in the tabular array 3.1.

Table 3.15: Calculation of recovery per centum of mix criterion for waste A1 + 20ppm mix criterion ( 40ppm alternate through column ) 1 July 2010

Name of compound

Concentration of mark analyte ( ppm )

Concentration of mark analyte in the space ( ppm )

Concentration of mark analyte in the mix criterion ( ppm )

Recovery per centum of mix criterion ( % )

Terphenyl-d14

84.77

0.05

84.72

211.80

Benz ( a ) anthracene

18.77

0.11

18.66

93.30

Chrysene

20.26

0.1

20.16

100.80

Benzo ( B ) fluorenthene

18.39

0.04

18.35

91.75

Benzo ( K ) fluorenthene

20.33

0.04

20.29

101.45

Benzo ( a ) pyrene

17.64

0.05

17.59

87.95

Indeno ( 1,2,3-cd ) pyrene

10.91

0.01

10.9

54.50

Dibenzo ( a.h ) anthracene

11.26

0.03

11.23

56.15

Table 3.16: Calculation of recovery per centum of mix criterion for waste A2 + 20ppm mix criterion ( 40ppm alternate through column ) 1 July 2010

Name of compound

Concentration of mark analyte ( ppm )

Concentration of mark analyte in the space ( ppm )

Concentration of mark analyte in the mix criterion ( ppm )

Recovery per centum of mix criterion ( % )

Terphenyl-d14

88.11

0.05

88.06

220.15

Benz ( a ) anthracene

21.5

0.11

21.39

106.95

Chrysene

21.04

0.1

20.94

104.70

Benzo ( B ) fluorenthene

19.54

0.04

19.5

97.50

Benzo ( K ) fluorenthene

21.23

0.04

21.19

105.95

Benzo ( a ) pyrene

18.88

0.05

18.83

94.15

Indeno ( 1,2,3-cd ) pyrene

14.67

0.01

14.66

73.30

Dibenzo ( a.h ) anthracene

15.22

0.03

15.19

75.95

Note: The concentration of mark analyte in the space of waste A is taken from the concentration of mark analyte in the tabular array 3.2.

Table 3.17: Summary of Recovery per centum of mix criterion

Name of compound

Recovery per centum of mix criterion ( % )

Waste W1

Waste W2

Waste A1

Waste A2

Terphenyl-d14

131.05

215.65

211.8

220.15

Benz ( a ) anthracene

113.50

108.50

93.30

106.95

Chrysene

93.10

100.20

100.80

104.70

Benzo ( B ) fluorenthene

96.80

101.30

91.75

97.50

Benzo ( K ) fluorenthene

111.70

110.50

101.45

105.95

Benzo ( a ) pyrene

94.00

97.10

87.95

94.15

Indeno ( 1,2,3-cd ) pyrene

16.50

42.70

54.50

73.30

Dibenzo ( a.h ) anthracene

42.60

65.10

56.15

75.95

3.7.4 Quality Control

Table 3.18: Calculation of recovery per centum of mix criterion for QC 20ppm

( no alternate spiked ) 29 Jun 2010

Name of compound

Concentration of mark analyte ( ppm )

Recovery per centum of mix criterion ( % )

Benz ( a ) anthracene

21.62

108.1

Chrysene

22.67

113.35

Benzo ( B ) fluorenthene

22.16

110.8

Benzo ( K ) fluorenthene

22.16

110.8

Benzo ( a ) pyrene

20.18

100.9

Indeno ( 1,2,3-cd ) pyrene

15.3

76.5

Dibenzo ( a.h ) anthracene

17.34

86.7

3.8 Observations:

3.8.1 The eluent in the F2 which contains PAHs was in xanthous coloring material whereas the eluent in F1 which contains saturated aliphatic hydrocarbon was colourless.

Fraction 1: colourless Fraction 2: xanthous coloring material

3.8.2 When the fractions were exposed to the UV visible radiation, there was fluorescence occurred in F2 but non in F1. This is the preliminary identifying for the presence of PAHs in the waste oil sample. This can be shown by the undermentioned images:

Fraction 1: fluorescence did non happen Fraction 2: fluorescence occurred

3.8.3 The strength of xanthous coloring material of F2 in waste W is higher than in waste A.

3.9 Discussions:

3.9.1 Discussion on chromatograph

Refer to the chromatograph of 20ppm of PAHs mix criterions attached behind, there are 9 extremums represent to the 7 PAHs, internal criterion and alternate. It shows the keeping clip of the 7 mark PAHs every bit good as internal criterion ( perylene-d12 ) and foster ( terphenyl-d14 ) . The keeping clip of the 7 PAHs, internal criterion and alternate are:

Terphenyl-d14: 24.46 min

Benz ( a ) anthracene: 26.82 min

Chrysene: 26.91 min

Benzo ( B ) fluorenthene: 29.25 min

Benzo ( K ) fluorenthene: 29.30 min

Benzo ( a ) pyrene: 29.90 min

Perylene-d12: 30.02 min

Indeno ( 1,2,3-cd ) pyrene: 32.48 min

Dibenzo ( a, H ) anthracene: 32.56 min

From the chromatograph, we can detect that the splitting of the 9 extremums is moderate but they are still acceptable. There are somewhat overlapping of some extremums such as benzo ( B ) fluorenthene with benzo ( K ) fluorenthene and indeno ( 1,2,3-cd ) pyrene with dibenzo ( a, H ) anthracene because their keeping clip is rather close. If the extremums are overlapping excessively much, response of the several analyte will be really hard to be calculated and mistakes will besides happen. This is because response is calculated from the country occupied by a extremum, so if 2 extremums are overlapping, it is really hard to find the existent country of each extremum and the response obtained will merely be an estimate. This will indirectly act upon our consequences. To better the splitting, temperature scheduling can be increased.

3.9.2 Linearity of Calibration

The standardization cheque of the five different concentration of PAHs mix criterion can be used to set up the instrument ‘s additive dynamic scope. From the consequences above, we found that the comparative response factors of each analyte for the points are changeless because the per centum RSD is less than 20 over the on the job scope. Besides that, based on the standardization graphs obtained, the sample coefficient of finding ( r2 ) of all the analytes except benzo ( K ) fluorenthene which is 0.976 are greater than 0.99, so they are considered as the best least-squares tantrum. Although r2 of benzo ( K ) fluorenthene is non greater than 0.99, its value ( 0.976 ) is merely somewhat different from 0.99, so it can still be accepted as a good least-squares tantrum. Due to these two grounds, the instrument can be considered to hold additive response over the scope of lower limit to maximal concentration. Calibration should be checked at the beginning of every undertaking.

3.9.3 Verification of Calculation for PAHs

From the tabular array 5.7 to postpone 5.12, I can verify that the concentration of each analyte ( unit of Aµg/g ) in every sample which I calculated by utilizing the expression given above lucifers with the consequences obtained from the GC/MS. As a consequences, I can vouch that the concentration of analyte calculated by the GC/MS itself does non hold mistake and it is dependable. Furthermore, I found that the concentrations of each analyte in the unit of Aµg/g which are calculated from the expression are 10 times of that concentration given by the GC/MS which is in the unit of Aµg/mL. To change over the unit of Aµg/mL to Aµg/g, the value obtained from the GC/MS has to be multiplied with the volume of sample solution prepared which is 5mL and divided by the mass of waste oil sample used which is 0.5g. Since 5mL divided by 0.5g will obtain 10mL/g, the concentration in the unit of Aµg/g will be 10 times of the concentration in the unit of Aµg/mL. By and large, the consequences obtained from the GC/MS must be converted into the unit of Aµg/g because the bounds of concentration of PAHs nowadays in the waste oil which are given by the Department of Environment ( DOE ) are all in the unit of Aµg/g. Hence, it will be more convenient for us to compare the consequences with the DOE bounds.

Based on the tabular array 5.7 and table 5.8, we can preliminarily cognize the concentrations of the seven PAHs compounds in waste W and blow A samples and we besides found that they are within the DOE bounds. This is because the waste oil samples were straight run with GC/MS and they were non gone through the column, so we assumed that there is no loss or addition of any sum of compounds when being analysing in the GC/MS. The consequences can be farther confirmed by making sample recovery which will be discussed in the Section 5.9.4. On the other manus, the consequences from the tabular array 5.9 to postpone 5.12 can non be used to find the concentration of PAHs in the two samples because the samples did travel through the sample clean-up column, nevertheless, the recoveries of alternate obtained are non good as the recoveries are already out of the scope ( 80-120 % ) . Therefore, the consequences obtained are non dependable because we do non cognize whether the recoveries of sample analytes are good or non by mentioning the foster recovery. Based on the recovery of alternate, we can foretell that there might be loss or addition of some sum of PAHs during the sample clean-up procedure.

Furthermore, compared the concentration of each analyte in waste W to blow A in the tabular array 5.7 and table 5.8 severally, we found that the concentration of each PAH compound in waste W is higher than in waste A. This explains why the coloring material of eluent in waste W is more intense than in waste A. The higher the concentration of PAHs in the oil sample, the more intense the coloring material is.

3.9.4 Sample Recovery

Since the recoveries of alternates from the tabular array 5.9 to postpone 5.12 are non good, we can non guarantee that whether the recoveries of samples are good or non. Therefore, we used another manner to find the recoveries of samples. We spiked the known concentration of mix criterion into the waste oil sample and so followed by the sample clean-up procedure. After that, the consequences obtained minus with the concentration of each analyte in the waste oil samples in order to acquire the recoveries of mix criterion. The concentration of each analyte in the waste W and blow A can be obtained from the tabular array 5.7 and table 5.8 severally. From finding the recoveries of mix criterion, we can besides cognize the recoveries of oil samples.

Harmonizing to the consequences above ( table 5.17 ) , we found that the recovery per centum of the first five analytes ( Benz ( a ) anthracene, Chrysene, Benzo ( B ) fluorenthene, Benzo ( K ) fluorenthene and Benzo ( a ) pyrene ) in the mix criterion are considered good which is 87.95 % – 113.50 % , so we can reason that the recovery of these analytes in the samples is besides good, and we assumed that there is no or a small loss or addition of the sum of samples throughout the procedure. However, the recoveries of indeno ( 1,2,3-cd ) pyrene and dibenzo ( a, H ) anthracene in the mix criterion are non good, there recovery per centums are less than 80 % . This might be because these two analytes are non suited for being extracted at the concentration of mix criterion that we spiked. For waste W sample in which the concentration of mix criterion spiked is 10ppm, the recovery of these two analytes is lower than waste A sample in which the concentration of mix criterion spiked is 20ppm. This means that the recovery of these two compounds might be increased if we increase the concentration of mix criterion spiked into the samples.

In add-on, the recovery of alternate for the samples is besides non good but the recovery per centum is rather consistent. The bad recovery of alternate might be caused by the glasswork such as column that we used during the experiment. The column might non be cleaned decently with methylene chloride and hexane after antecedently used. Hence, there might be some contaminations or alternate of the old experiments left on the column. This will impact our consequences and do us can non obtain a good recovery of alternate. Besides that, the concentration of alternate itself ( 100ppm ) before being spiked into the sample might be altered. This is because the 100ppm of alternate was diluted from the 1000ppm of alternate stock solution with hexane, so there might be some hexane evaporated when exposed to the air before being spiked. If hexane evaporates, the concentration of alternate will be increased, so the recovery per centum of alternate will be really high.

3.9.5 Quality Control

From the tabular array 5.18, we observed that the recovery of the 20pppm of mix criterion is good plenty because it is within the scope from 80 % to120 % . Therefore, we can guarantee that the public presentation of instrument is good and there is no any escape of gas in the gas chromatography. If the recovery is out of the scope, jobs have to be discovered and solved before samples are run.

3.9.6 Others

Both fraction 1 and 2 can non be over concentrated by vaporization under dry N in the “ blow-down ” setup until being wholly dry because this may take to loss of sum of PAHs and so our consequences will be affected.

Hexane is used to pull out saturated aliphatic hydrocarbons which is the eluent collected in the Fraction 1 ( F1 ) . This is because hexane is a non-polar dissolver and saturated aliphatic hydrocarbons are besides non-polar. Therefore, when the column is eluted with hexane, non-polar compounds such as aliphatic hydrocarbons will come out together with the hexane. On the other manus, 1:1 DCM/hexane is used to pull out aromatic hydrocarbon compounds which are collected in F2. This is because 1:1 DCM/hexane has an intermediate mutual opposition which is similar to the mutual opposition of PAHs so they are eluted with 1:1 DCM/hexane.

In the portion of reagents, I mentioned that prior to utilize, glass wool, silica gel and Na sulfate have to be rinsed with dissolver. This is because drosss can be removed and they can pre-adapt the environment after rinsing with the dissolver. Besides that, during the sample clean-up, we should guarantee that the silica column is packed. If non, the silicon oxide column will be cracked when dissolver and samples pass through the column. Our consequences will be affected if column is cracked. In add-on, both fractions 2 which contain PAHs were fluorescent when exposed to ultraviolet ( UV ) visible radiation. This is because when the molecules of PAHs absorb UV visible radiation, they will be excited, and so breathing characteristic wavelengths of visible radiation.

Furthermore, internal criterion has to be added after sample clean-up and nitrogen blowing but non added when the sample readying like alternate and blend criterion. This is because the add-on of internal criterion is used to cipher the concentration of other unknown analytes. If it is added into the sample during the sample readying and so travel through sample clean-up, sum of internal criterion might be lost during the procedure. Hence, the concentration of analytes which is calculated depending on the concentration internal criterion will be affected. To avoid this job occur, internal criterion is added after sample clean-up.

3.10 Decision

The recoveries of benz ( a ) anthracene, chrysene, benzo ( B ) fluorenthene, benzo ( K ) fluorenthene and benzo ( a ) pyrene in waste oil samples are equally good which is from 87.95 % – 113.50 % . This per centum scope is within the credence standard ( 80 % -120 % ) . Therefore, we can guarantee that these five analytes can be determined by utilizing this method without any loss of sum. However, the recoveries of indeno ( 1,2,3-cd ) pyrene and dibenzo ( a, H ) anthracene are hapless. Thus, alteration has to be applied to increase the recovery such as increasing the concentration of mix criterion spiked into the samples.

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