Solvent Cut-off wavelengths

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1,2,4-trichlorobenzene. 350. 1,2-dichlorobenzene. 350. 295. 1,2-dichloroethane. 250. 230. 1,2-dimethoxyethane. 300. 220. 2,2,4-trimethylpentane. 230. 210.
   

Solvent Cut-off wavelengths Solvents

L0/nm

L1/nm

1,2,4-trichlorobenzene

350

1,2-dichlorobenzene

350

295

1,2-dichloroethane

250

230

1,2-dimethoxyethane

300

220

2,2,4-trimethylpentane

230

210

2-ethoxyethanol

280

210

2-methoxyethanol

270

200

2-propanol

240

205

4-methylpentanone

375

335

5-methylhexanone

350

330

acetone

340

330

acetonitrile

200

190

benzene

295

280

butan-2-one

345

330

chlorobenzene

310

285

chloroform

260

240

cyclohexane

235

200

cyclopentane

220

195

decalin

250

230

dichloromethane

245

230

diethyl ether

255

220

dimethylsulphoxide

330

285

ethanol

240

205

ethyl acetate

280

260

heptane

230

200

hexane

225

195

isobutanol

250

200

    methanol

240

205

n-butanol

245

215

n-butyl acetate

275

255

nitromethane

>400

380

NN-dimethylformamide

300

270

n-propanol

250

210

o-xylene

325

290

p-dioxane

290

220

pentane

230

200

Pyridine

345

325

s-butanol

285

260

tetrachloroethylene

320

290

tetrahydrofuran

280

220

toluene

315

285

trichloroethylene

>400

water

190

185

In this table, approximate wavelengths (nm) are specified below which the solvent absorbance may be unacceptable. For quantitative work, the cut-off may be set at a wavelength (L0) where the absorbance for 10 nm pathlength of the solvent exceeds 0.05 absorbance units (relative to water), i.e. A1cm>0.05. For qualitative work, it may still be feasible to work at significantly lower wavelengths and most analysts accept a cut-off based on the wavelength (L1) for A1cm > 1.0.