The analytical procedure is given e

The analytical procedure is given elsewhere (Simoneit et al.,2004b) but a brief summary follows. The samples of filter aliquots (1/10) were sonicated twice for 15 min each with DCM/methanol (2:1, v:v). The solvent extract was filtered and concentrated by use of a rotary evaporator and then under blow-down with dry nitrogen gas. Aliquots of the total extracts were reacted with N,O-bis-(trimethylsilyl)- trifluoroacetamide (BSTFA) containing 1% trimethylchlorosilane and pyridine for 3 h at 70 C to convert polar compounds to the trimethylsilyl (TMS) derivatives. This procedure derivatizes COOH and OH groups to the corresponding TMS esters and ethers, respectively. The silylated extracts were dried under N2 blow-down to remove the remaining BSTFA and pyridine, and then dissolved with n-hexane prior to injection.Deuterated tetracosane was added to all samples before extraction.Prior to instrumental analysis, known quantities of internal standard hexamethylbenzene were added to the samples.

ผลลัพธ์ (แอฟริกา) 1:

die analitiese prosedure word elders gegee (simoneit et al., 2004b), maar 'n kort opsomming volg. die monsters van filter aliquots (1/10) is twee keer sonicated vir 15 min elk met DCM / metanol (02:01, v: v). die oplosmiddel uittreksel is gefiltreer en gekonsentreer deur gebruik te maak van 'n roterende verdamper en dan onder blow-af met 'n droë stikstof gas. aliquots van die totale uittreksels is gereageer met n,.o-bis-(trimethylsilyl) - trifluoroacetamide (bstfa) met 1% trimethylchlorosilane en pyridine vir 3 uur op 70 c pool verbindings om te skakel na die trimethylsilyl (TMS) afgeleide instrumente. hierdie prosedure derivatizes COOH en O groepe aan die ooreenstemmende TMS esters en eters, onderskeidelik. die silylated uittreksels is gedroogde onder N2 blow-af in die oorblywende bstfa en piridien te verwyder.en dan ontbind met n-heksaan voor injection.deuterated tetracosane is om al die monsters bygevoeg voordat extraction.prior tot instrumentele analise, bekend hoeveelhede van interne standaard hexamethylbenzene is om die monsters bygevoeg.