ph lc 10.16. nh lng N,N-Dimethylanilin

Xc nh bng phng php sc k kh.

Phng php 1

Dung dch chun ni

Ha tan 50 mg N,N-diethylanilin trong 4 ml acid hydrocloric 0,1 N, pha long bng nc ti 50 ml. Pha long 1 ml dung dch thu c ti 100 ml bng nc.

Dung dch th

Ha tan 0,50 g ch phm trong 30 ml nc, thm 1 ml dung dch chun ni. iu chnh nhit ca dung dch ti 26 oC-28 oC. Thm 1ml dung dich natri hydroxyd 40%(TT). Lc cho tan hon ton. Thm 2 ml trimethylpentan (TT). Lc 2 pht, yn cho tch lp, dng lp trn.

Dung dch i chiu

Ha tan 50 mg N,N-dimethylanilin trong 4 ml acid hydrocloric 0,1 N, pha long bng nc ti 50 ml. Pha long 1 ml dung dch thu c ti 100 ml bng nc. Tip tc pha long 1 ml dung dch thu c ti 30 ml bng nc, thm 1 ml dung dch chun ni, 1 ml dung dch natri hydroxyd 40% (TT), 2 ml trimethylpentan (TT). Lc 2 pht, yn cho tch lp, dng lp trn.

iu kin sc k

Ct mao qun thu tinh , di 25m x 0,32 mm ng knh trong, ph lp polymer lin kt mng polymethylphenylsiloxan dy 0,52 mm

Kh mang : Heli dng cho sc k kh, t l chia dng 1:20, p sut u ct 5 kPa vi lu lng 20 ml /pht.

Detector ion ha ngn la.

B chia dng (spit liner) l mt ct di khong 1 cm, nhi t diatomit dng cho sc k kh tm 10 % (kl/kl) poly(dimethyl)siloxan).

Nhit : Duy tr nhit ct 150 oC trong 5 pht, sau tng n 275 oC vi tc 20 oC/ pht, ri gi 275 oC trong 3 pht. Nhit detector 300 oC, nhit bung tim 220 oC.

Th tch tim: 1 ml.

Thi gian lu ca N,N-dimethylanilin khong 3,6 pht; ca N,N diethylanilin khong 5,0 pht.

Phng php 2

Dung dch chun ni

Dung dch naphtalen 0,005 % trong cyclohexan (TT).

Dung dch th

Ha tan 1,00 g ch phm vi 5 ml natri hydroxid 1N trong ng thy tinh c nt mi, thm 1 ml dung dch chun ni. y kn, lc mnh trong 1 pht. Ly tm nu cn, dng lp trn.

Dung dch i chiu

Thm 2 ml acid hydrocloric m c v 20 ml nc vo 50,0 mg N,N-dimethylanilin, lc cho tan v pha long bng nc ct ti 50 ml. Pha long 5 ml dung dch ny ti 250 ml bng nc. Cho 1 ml dung dch thu c vo ng thy tinh c nt mi, thm 5 ml natri hydroxyd 1 N v 1 ml dung dch chun ni. y kn, lc mnh trong 1 pht, ly tm nu cn v dng lp trn.

iu kin sc k‎‎

Ct thy tinh di 2m x 2mm ng knh trong, c nhi bng t iatomit silan ha v c tm 3 % (kl/kl) polymethylphenylsiloxan.

Kh mang: Nitrogen dng cho sc k kh, vi lu lng 30 ml/ pht.

Detector ion ha ngn la.

Duy tr nhit ct 120 oC, nhit detector v bung tim 150 oC.

Th tch tim: 1 ml.