Gas Gas ChromatographyChromatography

(GC)(GC)

Instruments for gas-Instruments for gas-liquid chromatographyliquid chromatography

1- Carrier gas supply1- Carrier gas supply2- Sample injection system2- Sample injection system3- Column configuration3- Column configurationand column ovensand column ovens4- Detection systems4- Detection systems

2- Sample injection 2- Sample injection systemsystem

3- Column configurations 3- Column configurations and ovensand ovens

3-1 Open tubular columns3-1 Open tubular columns 3-2 Packed columns3-2 Packed columns 3-3 Temperature programming 3-3 Temperature programming

3-1 Open tubular 3-1 Open tubular columnscolumns

Wall-coated open tubular (WCOT)Wall-coated open tubular (WCOT) Support-coated open tubular Support-coated open tubular

(SCOT)(SCOT) Fused-silica open tubular (FSOT)Fused-silica open tubular (FSOT)

3-2 Packed columns3-2 Packed columns

Solid support materialsSolid support materials Particle size of supportsParticle size of supports

3-3 Temperature 3-3 Temperature programmingprogramming

4- Detection systems4- Detection systems

Flame Ionization detectors (FID)Flame Ionization detectors (FID) Thermal conductivity detectors Thermal conductivity detectors

(TCD)(TCD) Electron-capture detectors (ECD)Electron-capture detectors (ECD) Flame photometric detector (FPD)Flame photometric detector (FPD)

Flame Ionization Flame Ionization detectors (FID)detectors (FID)

Thermal conductivity Thermal conductivity detectors (TCD)detectors (TCD)

Electron-capture Electron-capture detectors (ECD)detectors (ECD)

Flame photometric Flame photometric detector (FPD)detector (FPD)

The stationary phaseThe stationary phase

Polydimethyl siloxane [OV-1,SE-30]Polydimethyl siloxane [OV-1,SE-30] Poly(phenylmethyldimethyl)siloxane Poly(phenylmethyldimethyl)siloxane

(10% phenyl) [OV-3,SE-52](10% phenyl) [OV-3,SE-52] Poly(trifluoropropyldimethyl)siloxan Poly(trifluoropropyldimethyl)siloxan

[OV-210][OV-210] Poly(phenylmethyl)siloxane(50% Poly(phenylmethyl)siloxane(50%

phenyl) [OV-17]phenyl) [OV-17] Polyethylene glycol [Carbowax 20M]Polyethylene glycol [Carbowax 20M] Poly(dicyanoallyldimethyl)siloxanePoly(dicyanoallyldimethyl)siloxane

Typical chromatograms Typical chromatograms with different stationary with different stationary phasesphases

Application of GCApplication of GC

Qualitative analysisQualitative analysis Quantitative analysisQuantitative analysis

Stir-Bar Sorptive Extractionof Trace Organic Compounds Stir-bar sorptive extraction is a new

solventless sample preparation method for the extraction and enrichment of organic compounds from aqueous matrices.

Stir bar sorptiveStir bar sorptive

SBSE-GC-ECD/FPD in the SBSE-GC-ECD/FPD in the Analysis of Pesticide Residues Analysis of Pesticide Residues in Passiflora alata Dryander in Passiflora alata Dryander Herbal TeasHerbal Teas SBSE in combination with GC-ECD/FPD SBSE in combination with GC-ECD/FPD

analysis is here applied to the analysis is here applied to the determination of 11 pesticides determination of 11 pesticides (hexachlorobenzene,lindane,chlorothal(hexachlorobenzene,lindane,chlorothalonil,parathion methyl,parathion onil,parathion methyl,parathion ethyl,fenitrothion,malathion,dieldrin,ethyl,fenitrothion,malathion,dieldrin,αα- - and and ββ-endosulfan,and tetradifon) in -endosulfan,and tetradifon) in herbal teas prepared with Passiflora herbal teas prepared with Passiflora alata Dryander spicked leaves.alata Dryander spicked leaves.

Experimental procedureExperimental procedure

Materials and reagentsMaterials and reagents Sample preparationSample preparation Capillary GC-ECD/FPD analysisCapillary GC-ECD/FPD analysis Thermal desorption-capillary Thermal desorption-capillary

GC/MS analysisGC/MS analysis

Results and discussionResults and discussion

SBSE-GC-ECD/FPD analysis of SBSE-GC-ECD/FPD analysis of spiked waterspiked water

SBSE-GC-ECD/FPD analysis of SBSE-GC-ECD/FPD analysis of spiked P. alata Herbal teasspiked P. alata Herbal teas

SBSE-GC-ECD/FPD analysis of P. SBSE-GC-ECD/FPD analysis of P. alata Herbal teas prepared with alata Herbal teas prepared with spiked plant materialspiked plant material

Fig 1. GC-ECD & GC-FPD profiles of the SBSE extract from a Fig 1. GC-ECD & GC-FPD profiles of the SBSE extract from a water sample spiked with 0.5 pg/water sample spiked with 0.5 pg/µl of OC pesticides & 1.5 µl of OC pesticides & 1.5 pg/pg/µl µl of OP pesticides:(1)hexachlorobenzene;(2)lindane;of OP pesticides:(1)hexachlorobenzene;(2)lindane;(3)chlorothalonil;(4)parathion methyl;(5)fenitorthion;(3)chlorothalonil;(4)parathion methyl;(5)fenitorthion;(6)malathion;(7)parathion ethyl;(8)(6)malathion;(7)parathion ethyl;(8)αα-endosulfan;(9)dieldrin;-endosulfan;(9)dieldrin;(10)(10)ββ-endosulfan;(11)tetradifon.-endosulfan;(11)tetradifon.

Fig 2.GC-ECD & GC-FPD profiles of the SBSE extract from a Fig 2.GC-ECD & GC-FPD profiles of the SBSE extract from a P.alata herbal tea spiked with 0.5 P.alata herbal tea spiked with 0.5 pg/pg/µl of OC pesticides & µl of OC pesticides & 1.5 1.5 pg/pg/µl of OP pesticides. µl of OP pesticides.

Table 3.Octanol/Water Partitioning Coefficients(Ko/w),Water Table 3.Octanol/Water Partitioning Coefficients(Ko/w),Water Solubility,Recoveries(R%),RSD% from Spiked Herbal Teas and Solubility,Recoveries(R%),RSD% from Spiked Herbal Teas and from Herbal Teas Made from Spiked Plant Material for the OC from Herbal Teas Made from Spiked Plant Material for the OC and OP Pesticides Investigated.and OP Pesticides Investigated.

Fig 3.GC-ECD & GC-FPD profiles of the SBSE extract from a Fig 3.GC-ECD & GC-FPD profiles of the SBSE extract from a P.alata herbal tea prepared with plant material spiked with 50 P.alata herbal tea prepared with plant material spiked with 50 ng/g of OC pesticides & 150 ng/g of OP pesticides.ng/g of OC pesticides & 150 ng/g of OP pesticides.

Table 5.Intermediate Precision Expressed as RSD(%),LOD,LOQ Table 5.Intermediate Precision Expressed as RSD(%),LOD,LOQ for Each OC & OP Pesticide Investigated.for Each OC & OP Pesticide Investigated.

ReferencesReferences

SKOOG,HOLLER,NIEMAN;’’ SKOOG,HOLLER,NIEMAN;’’ PRINCIPLES OF INSTRUMENTAL PRINCIPLES OF INSTRUMENTAL ANALYSIS “;FIFTH EDITION,(701-ANALYSIS “;FIFTH EDITION,(701-718),1999718),1999

J. Agric. Food Chem.,51,27-J. Agric. Food Chem.,51,27-33,200333,2003

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