11. DEFINATION OF SOLID PHASE EXTRACTION (SPE): “A solid phase extraction consists of bringing a liquid or gaseous test sample in contact with a solid phase, whereby the analyte is selectively adsorbed on the surface of the solid phase” Other solvents (liquids or gases)added to remove possible adsorbed matrix components Eluting solvent added to desorb analyte selectively 4
16. Principle of Solid Phase Extraction: Partitioning of compounds between two phases of solid and liquid Must having greater affinity for the solid phase than for the sample matrix Compounds retained on the solid phase can be removed by eluting solvent with a greater affinity for the analytes pH changes can be useful 8
17. In modern SPE the adsorbent is packed between two flitted disks in polypropylene cartridgeand liquid phases are passed through the cartridge either by suction or by positive pressure 9
26. Examples of selective stationary phases Reaction of phenobarbitone with pentafluorobenzyl bromide onto the adsorbent Amphetamine by Chiral derivatization of solid Phases Doxorubicin by the metal-loaded phases in which metal cation is loaded onto a reagent-labelled phase Molecularly imprinted polymers synthetic polymeric materials with specific cavities designed for a template molecule 16
27. Technical Data - Solid Phase Extraction (SPE) Media Product Sorbent Abbreviations Description  ODS Octadecyl silica 5% carbon load ODS-4 Octadecyl silica 14% carbon load, end capped* ODS-5 Octadecyl silica 18% carbon load, end capped C-8 Octyl silica 8.5% carbon load, end capped FLO Florisil™ Magnesium silicate NH2 Weak anion exchanger Primary amine SAX Strong anion exchanger Quaternary amine (-NR3+) SCX Strong cation exchanger Aromatic benzene sulfonic acid SIL Normal phase silica   * End capping masks residual silanol groups, reducing ionic affinity for amines. 17
28. Experimental procedure of five steps: Activation of sorbent by appropriate solvent that conditions the surface of the solid 2. Removal of solvent by liquid similar to the sample matrix 3. Application of sample, the analytes retained by the sorbent 4. Removal of interfering compounds retained in step 3 with a solvent, but shouldn’t remove the analytes (washing step) 5.Elution of the analytes with an appropriate solvent (desorption or elution step) and collecting for analysis  18
34. Other technique can be used Supercritical fluid Thermal desorption for analytes of high volatility and thermal stability Thermal desorption with GC for occupational hygiene analysis 24
35. Analyte eluted with an organic, relatively volatile solvent is evaporated to dryness Then residue dissolved in appropriate solvent Due to evaporation step, speed with SPE is lost 25
36. IMMUNOAFFINITY PHASES: Highly selective packings of Immunoaffinity phases of specific antibody immobilised on solid support such as agarose or silica Useful for selective extraction of biological importance Substance Diagnosis of cancer ELISA TEST Â Â 26
38. TRACE ENRICHMENT WITH SPE Sensitivity depends on Physicochemical properties of the Analyte Detection system Selective clean-up Isolation and concentration step 28
39. Solid phase microextraction: SPME is the technique in which by using special instrument, sampling is possible in a vapour state 29
40. Design of SPME Syringe like instrument Fused silica fiber of a small size and cylindrical shape connected to stainless-steel tube for additional mechanical strength and repeated sampling 30
42. Fused silica fibre coated with thin film of several polymeric stationary phases Reusable and replaceable Small size and cylindrical geometry of fiber Placement into sample or headspace is easy Loading in desorption chamber of GC or Interphase of the HPLC without any modification of Plunger 32
43. Working with SPME Fiber is first drawn into the syringe needle Lowered into the vial by pressing the plunger Fiber cleaned before analysis to remove contaminants Cleaning can be performed in the desorption chamber of HPLC by running solvent Cleaned fiber coating is exposed to a sample matrix for a predetermined, fixed period 33
45. Limits of detection at the µg/L level with using a flame Ionization detector Limits of detection as low as ng/ L can be reached with an ion-trap mass spectrometer 35
46. Extraction can be performed in two ways 1) Headspace SPME or HS-SPME Fiber is exposed in the vapour phase above a gaseous, liquid, or solid sample 2) Direct immersion or DI-SPME Fiber is directly immersed in liquid samples 36
47. Available SPME Fibres, by Film Type •Absorption Fibres -Polydimethylsiloxane (PDMS) 7, 30, and 100μm Unpolar -Polyacrylate (PA) Polar -Polyethylene glycol (PEG) Polar  •Adsorption fibres (with particles) -Carboxen-polydimethylsiloxane (CAR-PDMS) Adsorption -Polydimethylsiloxane- divinylbenzene (PDMS-DVB) Adsorption -Divinylbenzene/ Carboxen-Polydimethylsiloxane (DVB-CAR-PDMS) Adsorption   37
48. SPME applied to liquid, gaseous or heavily contaminated samples chemicals like Substituted benzene compounds Polyaromatic hydrocarbons Nitro- and chlorophenols Naphthols volatile organochlorine compounds polychlorinated biphenyl congeners caffeine Metallic ions  38
49. The SPE process can be performed in a two ways: On-line Off-line In offline SPE eluate from the cartridge is introduced into the chromatograph by means of an injection valve In on-line SPE the extraction cartridge is inserted as part of chromatographic equipment, as loops or high pressure stream of the mobile phase 39
58. Advantages of SPE offers over LLE are Higher selectivity Cleaner extracts More reproducibility The avoidance of emulsion formation 48
59. Application of SPE in various fields Impurity profiling of pharmaceuticals Environmental applications Applications in food chemistry Analysis of wines and other alcoholic beverages Application to biological fluids Hair analysis 49
60. Impurity profiling of pharmaceuticals Residual solvent analysis by USP 467 Involves head space solid phase micro extraction with GC and FID detector 50
61. Application to biological fluids: Simultaneous qualitative and quantitative determination of Drugs of abuse opiates, cocaine, or amphetamines Prescribed drugs tricycle antidepressants,phenotiazines, benzodiazepines in biological fluids was developed Eg. A Weak Cation-Exchange Monolithic SPE Column for Extraction and Analysis of Caffeine and Theophylline in Human Urine 51
62. Urinary Excretion Pattern of Benzophenone-3 and its Metabolite 2,4-Dihydroxybenzophenone in Human Urine 52
63. Hair analysis It is used for the long-term monitoring of drug and alcohol 53