Sample Preparation in Chromatography

VII

Table of Contents Part 1. Introduction and General Considerations 1. Preparatory Information 1.1. 1.2. 1.3. 1.4. 1.5. 1.6. 1.7. 1.8. 1.9. 1.10. 1.11. 1.12.

2.

Sampling and Its Connection with Sample Preparation 2.1. 2.2. 2.3. 2.4.

3.

Overview of a Chemical Analysis 3 Types of Operations Used in Sample Preparation 10 Some Theoretical Aspects of Phase Transfers 16 Introductory Approach to Theory of Distribution Equilibria 24 Some Aspects of Mass Transfer Processes 33 Characterization of Chromatographic Separations 43 General Characteristics of Separations 61 Elementary Discussion on Thermodynamic and Kinetic Factors in Chemical Reactions 66 Brief Survey on Molecular Interactions 69 Empirical and Estimated Parameters for Sample Preparation Problems... 77 Introductory Discussion on Precision, Accuracy, Sensitivity, and Limit of Detection in Chemical Analysis 94 Validation of an Analytical Method 107 References 1 108

Relation of Sampling to Sample Preparation Representative Samples Techniques for Sample Collection Handling, Preservation, and Storage of Samples References 2

113 114 118 130 132

Overview on Sample Preparation for Chromatography 3.1. 3.2. 3.3. 3.4. 3.5. 3.6. 3.7. 3.8. 3.9.

The Role of Sample Preparation The Use of Preliminary Information for the Choice of a Sample Preparation Procedure Sample Homogenization and Dissolution Sample Cleanup, Fractionation, and Concentration Chemical Modifications of the Sample Other Types of Sample Modifications Differences in Sample Preparation for Different Chromatographic Techniques Quantitation Techniques in Chromatography and Their Relation to Sample Preparation Method Development in Sample Preparation References 3

137 141 146 147 152 153 154 156 159 163

viii

Table of Contents 4.

Chromatography as the Core Step in an Analytical Process 4.1. 4.2. 4.3. 4.4.

The Choice of the Core Analytical Technique Gas Chromatography as a Core Step in the Analytical Process Conventional High Performance Liquid Chromatography as a Core Analytical Technique Other Chromatography Types Used as a Core Analytical Technique References 4

165 169 182 201 209

5. Data Processing in Chromatographic Methods 5.1. 5.2.

6.

Information Gain from Chromatographic Data Qualitative and Quantitative Data from the Chromatographic Process References 5

213 214 218

Automation in Sample Preparation 6.1. 6.2.

Automation in the Instrumentation Used in Sample Preparation Computer Assisted Method Development References 6

219 221 221

Part 2. Sample Preparation Techniques Using Physical Processes 7.

Mechanical Processing in Sample Preparation 7.1. 7.2. 7.3.

8

225 238 241

Phase Transfer Separations Applied in Sample Preparations 8.1. 8.2.

9.

Grinding, Sieving, and Blending Filtration, Microfiltration, and Ultrafiltration Centrifugation References 7

Distillation, Vaporization, and Drying Dissolution, Crystallization, and Precipitation References 8

243 255 265

Headspace Sampling Techniques in Gas Chromatography 9.1. 9.2. 9.3.

Static Headspace Techniques Dynamic Headspace Other Headspace Techniques References 9

267 272 283 285

ix

Table of Contents 10. Solvent Extraction 10.1. 10.2. 10.3. 10.4. 10.5. 10.6.

Liquid-Liquid Extraction Conventional Liquid-Solid Extraction Accelerated Solvent Extraction Microwave-Assisted Solvent Extraction Simultaneous Distillation and Extraction Supercritical Solvent Extraction References 10

287 304 310 314 317 322 334

11. Sorbent Extraction 11.1. 11.2. 11.3. 11.4.

Solid Phase Extraction Procedures Solid Phase Microextraction Matrix Solid Phase Dispersion Other Solid Phase Sample Preparation Techniques References 11

341 373 394 396 399

12. Chromatographic Procedures as Preliminary Separation 12.1. 12.2. 12.3.

Gas Chromatography as a Sample Preparation Technique and Bidimensional GC Liquid Chromatography as a Sample Preparation Technique Size Exclusion Used in Sample Preparation References 12

403 408 415 420

13. Membrane Separations 13.1. 13.2.

Gas Diffusion through Membranes and Stripping Reverse Osmosis and Dialysis References 13

423 425 431

14. Electroseparation Techniques in Sample Preparation 14.1. 14.2.

Electrophoretic Techniques Other Electroseparation Techniques References 14

433 440 441

15. Other Separation Techniques in Sample Preparation 15.1. 15.2.

Ion Exchange in Sample Preparation Other Techniques in Sample Preparation References 15

443 459 460

X

Table of Contents Part 3. Sample Preparation Techniques Involving Chemical Modifications 16. Chemical Modifications for Dissolution and Fractionation 16.1. 16.2.

Chemical Modifications for Sample Dissolution 463 Changes in pH and Chemical Modifications for Fractionation Purposes... 466 References 16 470

17. Purpose of Derivatization in Chromatographic Analysis 17.1. 17.2. 17.3. 17.4. 17.5. 17.6. 17.7.

General Aspects Regarding Derivatization Preparation of the Sample for Derivatization and Common Derivatization Labware Derivatization for Improving Gas Chromatographic Process Derivatization for Improving Detection in GC Derivatization for Improving Mass Spectral Identification Derivatization for Improving Detection in HPLC and TLC Derivatization for Chiral Separations References 17

473 476 478 486 493 502 514 523

18. Chemical Reactions Used in Derivatization 18.1. 18.2. 18.3. 18.4. 18.5. 18.6. 18.7. 18.8.

Reactions with Formation of Alkyl or Aryl Derivatives Silylation Reactions Acylation Reactions Reactions of Addition to Carbon-Heteroatom Multiple Bonds Used for Derivatization Derivatization Reactions with Formation of Cyclic Compounds Other Derivatization Reactions Derivatization Reactions Involving Solid Phase Reagents Derivatization on a Solid Support References 18

525 545 569 581 591 .613 623 629 631

19. Derivatization Reactions for Analytes with Various Functional Groups 19.1. 19.2. 19.3. 19.4. 19.5. 19.6. 19.7. 19.8.

Derivatization of Compounds with Alcohols, Epoxide, or Ether Groups.... 639 Derivatization Reactions for Phenols 669 Derivatization Reactions for Thiols and Sulfides 675 Derivatization of Compounds with Amino and Other Nitrogen-Containing Groups 683 Derivatization of Aldehydes and Ketones 724 Derivatization of Carboxylic Acids 739 Derivatization of Amides, Esters, and Other Derivatives of Carboxylic Acids, and of Carbonic Acid 761 Derivatization of Other Types of Organic Groups and of Organometallic and Inorganic Compounds 776

XI

Table of Contents 19.9. Derivatization of Carbohydrates 19.10. Derivatization of Amino Acids and Related Compounds 19.11. Derivatization of Other Multifunctional Compounds References 19

788 798 814 823

20. Chemical Degradation of Polymers and Pyrolysis 20.1. 20.2. 20.3. 20.4. 20.5. 20.6. 20.7.

Chemical Degradation of Polymeric Carbohydrates Chemical Degradation of Proteins for Analytical Purposes Chemical Degradation of other Macromolecular Compounds Overview of Analytical Pyrolysis Pyrolysis as a Chemical Modification Technique Instrumentation Used in Analytical Pyrolysis Application of Analytical Pyrolysis References 20

847 859 864 869 877 895 901 913

Symbols, Units, and Constants

919

Index

923

923

INDEX

absolute capacity factor absolute retention time accuracy acid digestion acidity constants activation energy activity coefficient acyi halides

45 44 95,98 464 540, 684, 739, 799 69 22 761

adaptability to analyte volatility addition to a double bond adsorption constant AED (atomic emission detector) affinity sorbents Ag/AgCt electrode alcohols ALD (aroyl-luminescence detector) aldehydes Allyl-TMS (altyltrimethylsilane) alumina amides

62 613 30 180, 486 357 196 639 180 724 546 276 761

amines amino acids

683 710, 798

amino alcohols amino phenols amino sugars analysis of volatiles analytes anhydrides

815 815 792 267 3 761

APCI (atmospheric pressure ionization) aromatic ring substitutions Arrhenius reaction rate equation artifact formation in trimethytsilylation reactions artifacts in acylation

166, 199 620 69 564

artifacts in alkylation artifacts in distillation artifacts in liquid solid extraction artifacts in dynamic headspace ASE (accelerated solvent extraction) average azeotropic composition

541 247 256,265 272 310 95 22

580

azeotropic distillation

247

azides azines azoles

761 604 600

B B.E.T. isotherms basicity constants BASTFA (N.Obis(allyldimethylsilyl)tnfluoro-acetamide) batch extraction batch sample processing BDSA(bis(dimethylsilyl)acetamide) bidimensional GC bile acids binomial experiment blank sample blending boiling point bond energies bond energies for Si-X BOP (benzotriazol-1-yl-oxytris(dimethylamino)-phosphonium hexafluorophosphate) bottom (in distillation) breakthrough volume Vb BSA (N,0-bis(trimethylsilyl)-acetamide) BSB(N,0-bis(trimethylsilyl)-benzamide) BSC (N,0-bis(thmethylsilyl)-carbamate) BSF(N,N-bis(trimethylsilyl)formamide) BSS (bis(trimethylsilyl)sulfate) BSTFA (N,0-bis(trimethylsilyl)trifluoroacetamide) BSU(N,N'-bis(trimethylsilyl)urea) buffer solutions bulk chromatographic phases

31 684 554 287 219 555 113 667 117 159 225 80 872 561 520

244 276, 278, 343 546 546 546 547 547 547 547 466 178

C C8 (silica base octyl sorbent) C18 (silica base octadecyl sorbent) X2 distribution CA (cellulose acetate) calibration standard capacity factor carbamates or urethanes

185 93, 185 98 233 156 28,48 772

Index

924

carbohydrates carbonyl azides in derivatization carbonyl compounds carborane stationary phase in GC carboxylic acids CCBBT(6-chloro-1-pchlorobenzensulfonyloxybenzotriazole) CD! (N.N'-carbodiimidazole) CE (capillary electrophoresis) CEDMSDEA (2cyanoethyldimethyl(diethyl)aminosilane) chain scission in pyrolysis charcoal sorbents charge transfer interactions chelating resins chemical potential chemiluminescencedetection in HPLC chemilumjnescence efficiency chirai chromatographic columns chiral reagents chirality

661, 735, 788 579 582, 724 177 739 534 534 9 554

crystallization

263

cumulative frequency distribution cyclic boronates cyclic phosphothionates cyclic siliconides cyclopropane containing carboxylic acids

96 610 610 606 759

D Dalton's law DCCI (dicydohexylcarbodiimide)

denuder tube 882 deproteinization 276 74 derivatization labware desiccants 455 14 detection limit determination limit 195,510 Dialog Corp. 195 519 dialysis _ diastereoisomers 520 Diazald (N-nitroso-N-methyl-p514 toluenesulfonamide) chloroformates 577 diazomethane generator dienes 157 chromatographic standard differential migrating processes chromatographic stationary phases (GC) 178 diffusion coefficient CI+ (positive ions chemical ionization) 217 Clausius-Clapeyron equation diffusive sampler 18,89, 252 closed-loop stripping 284 dimethyl polysiloxane diois CMDMCS 554 ((chloromethyl)dimethylchlorosilane) dipole-dipole interactions CMTMDS (1,3-bis(chloromethyl)-1,1,3,3- 554 tetramethyldisilazane) colloid solutions 263, 238 disaccharides concentration polarization 230, 427 dispersion interactions dissociation energies concentration process 148 dissolution concurrent sequential sample processingI 219 distribution constant conformers 516 distribution equilibrium in SPME continuous extraction 291 distribution process in gas convenience sampling 115 chromatography distribution process in HPLC core analytical process (step) 3,8 dithionic acid esters countercurrent separations 65 DMCS (dimethyldichlorosilane) countercurrent-with-reflux separations 66 DMCTMS (trimethylsilyl N,Ncritical point 18 dimethylcarbamate) 18,324 critical temperature DMF (dimethylformamide) DMIPCS (isopropyldimethylchlorosilane) crosscurrent processes 65 DMMCS (dimethylmonochlorosilane) 527 cryptands DMSO (dimethylsulfoxide) 177 cyanopropyl polysiloxane

19 534 124 266 477 254 103 107 6 427 514 530 531 776 66 41,80 127 178,376 658 71 789 72 872 256 25 378 43 46 761 555 548 526 556 666 525

925

Index

DNA (deoxyribonucleic acid)

821, 866

DNA sequencing dry ashing dry weight basis drying dynamic gas sampling

867 464 253 253,279 121

F distribution FAB (fast atom bombardment) Fick's first law Fick's second law FID (flame ionization detector)

dynamic headspace dynamic separations

272 65

filter materials filter properties filtration finite interaction

EA (electron affinities) EA (electron affinity) ECD (electron capture detector)

489 488 180,492

14 68 586

EDAC (1 -(3-dimethyiaminopropyl)-3ethylcarbodiimide) Edman degradation effective plate number El+Jpqsitive ions electron ionization) electrochemical detection in HPLC electrochromatography electrode potential electrodialysis electrophoretic mobility ELSD (evaporative light-scattering detector) elutropic strength Emerson reaction

535

first law of thermodynamics first order reaction rate FLOROX (O-(pentafluorobenzyl)hydroxylarnine hydrochloride) fluorescence detection in HPLC

862 51 217 195,512 209 196 440 435 200

fluorescence efficiency Florisii FPD (flame photometry detector) fraction of moles in the mobile phase fractional distillation fractionation fractionation capacity frequency factor FTIR (Fourier transform IR)

194 277 180 44 246 148 61 69 181

48, 189 673

F 98 200 33 34 166,180, 486 231 229 226 77

193, 506

G

emulsion formation enantiomers enrichment factor EPA (United States Environmental Protection Agency) epoxides equilibrium constant error-function error-function complement ES (electrospray) esters of carbonic acids estimation of distribution constants estimation of solubility ethers

298 514 149 133

gamma function gas-liquid equilibrium gas-liquid partition gas-solid adsorption

37 19 27 29

668 67, 451 37 37 166, 199 761 88,90 85 669

35 8 174, 177 171 173 179 403 17 424

ETSA (ethyl trimethylsilylacetate) extensive variables external calibration standard external information extraction of ionic species extrathermodynamic estimations

547 17 156 141 289 81

Gaussian bell curve GC (gas chromatography) GC columns GC injection techniques GC oven GC detectors GC-GC (bidimensional GC) Gibbs phase rule GIME (gas injection membrane extraction) glycosidic linkage GPC (gel permeation chromatography) gradient elution gradient temperature GC grinding guanidines

855 202,416 57 58 225 773

Index

926 166 half wave potential Hall (electrolytic conductivity detector)

197 180

HCB (hexachlorobenzene) headspace height equivalent to a theoretical plate Henry's constant Henry's law heterocyclic amines HFBA (heptafluorobutyric anhydride) HID (helium ionization detector) HMDS (hexamethyldisilazane) HMDSO (hexamethyldisiloxane)

321 267 51 90, 378 27 718 492, 572 180 547 547

Hofmann degradation homogenization

622 146

HPLC (high performance liquid chromatography) HPLC columns hydrazides hydrazines

182

keto acids

816

185 769 722

ketones KovSts retention index Kuderna Danish (KD) evaporative concentrator

724 60, 176 252

hydrogen bond hydrolysis

74 619

hydroxamic acids hydroxy acids hydroxylamines

771 816 723

1 IC (ion chromatography) ICP (inductively coupled plasma) imino ethers immunoaffinity chromatography Immunoelectrophoresis indoles informational entropy inorganic compounds instrumentation in pyrolysis intensive variables internal standard

125,202 200 761 207 439 715 213 782 895 17 157

ion exchange capacity ion exchange resins ion exchange SPE sorbents ion pair chromatography ionic strength intermolecular forces IPOTMS ((isopropenyloxy)trimethyl-

448 443 357 204 429 71 547

silane

IRD (infrared detector) ISO International Standardization Organization isocyanates isocyanates in derivatization isoelectric focusing isokinetic sampling isolated (closed) system isotachophoresis isothermal GC isothiocyanates in derivatization isotope labeling IUPAC (International Union of Pure and Applied Chemistry)

180 107 776 579, 587 171 122 66 169 58 579, 587 498 4»o

9

K

L Langmuir adsorption isotherm large volume sample introduction system LC (liquid chromatography) LC-GC (liquid chromatography-gas chromatography) LC-LC (liquid chromatography-liquid chromatography) least-squares fitting Lenard-Jones equation LIF (laser induced fluorescence) lignin limiting current intensity linearity of response lipids liquid membranes liquid sample collection liquid-liquid partition liquid-liquid partition of compounds simultaneously in ionic and nonionic form liquid-liquid partition of ion pairs liquid-solid equilibrium LLE (liquid-liquid extraction) load capacity LSE (liquid-solid extraction) LTPRI index lyophilization (freeze-drying)

30 171 182 412 409 100 73 194 865 199 102, 108 773 430 128 24 32 31 23 287 62 304 60 255

927

Index

nttriles

761

315 33 39

nitrogen chemiluminescent detector NMR (nuclear magnetic resonance) non-Gaussian peaks

180 200 54

3 574

nonaromatic cycle formation nonelectrolytes

591 256

233 176,485 95

nonpolar SPE sorbents normal distribution NPD (nitrogen phosphorus detector)

352 96 166, 180, 487 792 263 821 821

M MAE (microwave assisted extraction) mass transfer by diffusion mass transfer by diffusion and convection matrix MBTFA (2,2,2-trifluoro-N-methyl-N(2,2,2-trifluoroacetyl)acetamide) MCE (mixed cellulose esters) McReynolds constant mean

mean of the population 95 membrane materials 231 membrane properties 229 MESI (membrane extraction with sorbent 424 interface) 4 method Methyl-8 (N,N-dimethylformamide dimethyl acetal) microti Itration MIMS (membrane introduction mass spectrometry) MMTSP (1-methoxy-2-methyl-1trimethylsiloxypropene) modifiers in SFE moisture removal in SPE molar volume mole fraction molecular distillation molecular imprinted sorbents monosaccharides MOPAC (molecular orbital calculation package) moving boundary electrophoresis MS (mass spectroscopy or spectrometry) MSA (N-methyl-N-trimethylsilylacetamide) MSD (mass selective detector) MSDP (matrix solid phase dispersion) MSHFBA (N-methyl-Ntrimethylsilylheptafluorobutyr-amide) MSTFA (N-methyl-N-trimethylsilyltrifluoroacetamide) MTBSTFA (N-methyl-N-(tertbutyldimethylsilyl)-trifluoroacetamide)

532

number of peaks separated in a chromatogram NYL (nylon)

226 424

61 233

O

547

octanol/water partition coefficients

81

327 358 26, 259 17 251 358 789 479,559

ODS columns (octadecyl silica) on-line instrumentation OPA (o-phthalaldehyde) operational aspects of separations organometallic compounds OTT (open tubular trapping) overpotential oxidations and reductions

185 220 597 64 782 398 198 615

437 487,514 548

oximes

723

180 394 548

PAH (polycyclic aromatic hydrocarbons) parachor parameters for solvent characterization

372 80 87

548

partition coefficient

25

554

PB (particle beam)

200,513

PBM (probability based matching of mass spectra) PCB (polychlorinated biphenyls)

494

PDMS (polydimethylsiloxane) peak broadening peak capacity peak separation

177,395 49 61 55

N NCI (negative chemical ionization) Nernst equation NH2 sorbent (column) NHE (standard hydrogen electrode)

neuraminic acid nucleation nucleosides nucleotides

490 197 349 196

P

308

Index

928 peak width

50

PEEK (polyetheretherketone) peptide bond formation peptides performance of SPE phases

184 573 813, 861 351

quantitation limit quaternary ammonium compounds

peracids permeate PES (polyethersutfone) PFPA (pentafluoropropionic anhydride) pH modification phase phase ratio phenols phosphate esters phosphonates

761 235 233 492, 572 466, 476 12 46 669 778 778

PID (phototonization detector) Pirkle chiral chromatographic columns plate height polar SPE sorbents polarity parameter P' polarizability polymeric carbohydrates polyols population porous polymers precipitation precision prostaglandins proteins PS-DVB-EVB (polystyrenedivinylbenzne/ethylvinylbenzene) PS-DVB-NVP (polystyrenedivinylbenzne/N-vinytpyrrolidone) PTFE (potytretrafluoroethylene, teflon) PTV (programmed temperature vaporizer) purge and trap (P&T)

166, 200 519 52 354 86 72,479 797, 847 658 95 270, 278 265 95, 101 818 813, 859 350

random error random sampling Raoult's (aw RCF (relative centrifugal force) reaction rate recovery reduced parameters refractive index rejection characteristic of membranes relative frequency of occurrence of random errors relative humidity repeatability representative samples representativeness of sampling reproducibility resolution response factor retention index in gas chromatography retention time retention volume reverse osmosis

273

salting out

purpose of analysis PVDF (polyvinylidene fluoride) pyridine pyrolytic elimination pyrolysis in the presence of reactants pyrolysis with derivatization pyrolysis of natural organic polymers pyrolysis of small molecules pyrolysis of synthetic polymers pyrroles

142 233 721 879 888 898 901 912 905 715

sample sample capacity sample cleanup sample collection saturated solution SAX columns (strong anion exchange) SBSE (stir bar sorptive extraction) SCE (saturated calomel electrode) SCX columns (strong cation exchange) SDE (simultaneous distillation and extraction)

350

Q 107 721

R 94 113 15,21 238 68 108, 149 324 80, 191 230 96

RH (relative humidity) RNA (ribonucleic acid) robustness

253 108 114 115 108 56, 437 159 60 44 44 226,425 48 131 821,866 108

ruggedness

108

Rf

126 58,171

S 260, 275, 297 95 57 147 118 256 185 396 196 185 318

929

Index

SDS-PAGE (sodium dodecyl sulfate polyacrylamide gels electrophoresis) SDVB (styrene-divinylbenzene, polymer) SEC (size exclusion chromatography) sensitivity separation factor

438

93 201, 416 102 21, 29, 55 , 289 sequential sample processing 219 SFC (supercritical fluid chromatography) 208 323 SFE (supercritical fluid or solvent extraction) short path thermal desorption 284 side group reactions is pyrolysis 886 sieving 225 105 signal to noise ratio S/N 346 silica base sorbents 277 silica gel 181 SIM (single ion monitoring) 65 single contact separations SN1 mechanism 540 540, 560 SN2 mechanism solid sample collection 129 85,256 solubility solubility parameter 26, 259 solubility product 261 427 solute loss in reverse osmosis 86, 260, solvent polarity 298, 363 86, 298, solvent properties 363,476 188 solvent solubility in water 139 solvent-free sample preparation 852 solvolysis solvophobic interactions 75 Soxhlet extraction Soxtec extractor SPE (solid phase extraction)

307 309 153, 341

SPE accessories (formats)

365

SPE fibers

377

specific rotation specificity/selectivity

517 108

SPME (solid phase microextraction)

271, 374, 899 284 108, 260 267

spray and trap stability static headspace (SHS)

standard addition in quantitation

158

standard deviation standard electrochemical potential standard error static and trapped headspace (S&THS)

95 196 96 284

static gas sampling static separations steam distillation

121 65 248

steam distillation and extraction stereoisomers steroids derivatization STOX (hydroxylamine hydrochloride) stratified sampling Student function sublimation substituted amides sugar acids sugar phosphates sulfates sulfides sulfonic acids sulfonyt derivatives sulfur chemiluminescence detector supersaturation

318 514 665,818 586 114 97 264 761 792 792 780 675 780 578 180 262

syn-anti isomers

514

systematic errors systematic sampling

94 114

T 98 t-test TBDMCS(tert-butyldimethylchlorosilane) 554 554 TBDMS triflate (tert-butyldimethylsilyl trifluoromethanesulfonate) TBDMSacac(4-tert-butyldimethylsiloxy-3 - 5 5 4 penten-2-one) 554 TBDMSI (1-(terfbutyldimethylsilyl)imidazole) TBDPCS (terf-butyldiphenyichlorosilane) 554 168, 178. TCD (thermal conductivity detector) 486 322 TCDD (tetrachlorodibenzo-p-dioxin) TCEP (1,2,3-tris(2-cyanoethoxy)propane;) 176 270 teabag headspace 4 technique

930

Index

techniques for gas collection TFAA (trifluqroacetic anhydride) theoretical plate height theoretical plate number

120 492,572 53 51

ureas UV-Vis (ultraviolet-visible)

thermochemolysis thermodynamic distribution constant tertiary amines THF (tetrahydrofuran) thiocyanates thiohydantoins thiols THT (total heating time) tie line (in distillation) TLC (thin layer chromatography)

890 24 721 476 761 812 675 869 244 207

vacuum distillation validation van Deemter equation van der Waals forces vapor-liquid equilibrium vaporization viscosity VOC (volatile organic compounds)

TMAAc (tetramethylammonium acetate) 536 TMAH (tetramethylammonium hydroxide]) 536 547 TMBS (bromotrimethylsilane) 547 TMCS (chlorotrimethylsilane) TMDS (1,1,3,3-tertamethyldisilazane) 555 547 TMIS (iodotrimethylsilane) I M S (trimethyisilyl) 545 548 TMSA (N-trimethylsilylacetamide) TMSacac((4-trimethylsiloxy-3-pentene-2 - 5 4 8 one or (trimethyisilyl enol of acetylacetone)) 548 TMSCN (trimethyisilyl cyanide) TMSDEA(N,N-diethyl-N-trimethylsilyl547 amine) 547 TMSDMA (N.N-dimethyl-Ntrimethylsilylamine) TMSI (TMSIM) (N-trimethylsilylimidazole) 549 TMSO (3-trimethylsilyl-2-oxazolidinone) 549 TMSPI (N-trimethylsilylpiperidine) 549 TMSTCA (trimethyisilyl trichloroacetate) 549 TMSTF (TMS triflate) (trimethyisilyl 549 trifluoromethanesulfonate) (triflate) 554 TMTBS-CI (cyclotetramethylene-terfbutylchlorosilane) 536 TMTFTH (trimethyttrifluoro-m-tolyl ammonium hydroxide) 556 TPDMDS (1,3-dimethyH, 1,3,3tetraphenyldisifazane) TPSA (triphenylsilylamine) 556 transesterifi cation 537 TRT (temperature rise time) 869 TS (thermospray) 166,200, 513 TsOH (toluenesulfonic acid) 663

ultrafiltration unsaturated acids

226 759

761 191,504

V 247 107 53 70, 480 19 251 41,228 119,267

Z zeolites zeta potential

277 166