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Chromatographic scince series - Cazes J.

Cazes J. Chromatographic scince series - Marcel Dekker, 1996. - 1098 p.
ISBN 0-8247-9454-0
Download (direct link): сhromatography1996.pdf
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Simazine, atrazine, trietazine, propazine, terbutylazine, and sebutylazine belong to the group of symmetric triazines characterized by the structure XIV; prometon and atraton are characterized by structure XV; and simetryn, prometryn, desmetryn, methoprotryn, and terbutryn by structure XVI. Triazines can be determined without thorough cleanup using detection by the Hill reaction (see Section V.C.l), but several other sensitive methods are also known.
In this section only methods dealing with the triazine-type herbicides will be reviewed. Multiresidue methods covering the determination of triazines among others will be treated in Section UI.G. For the separation of triazines there is a large variety of quite different thin-layer sorbents. Both silica gel GF254 (74) and alkaline zinc carbonate sheets were used for the separation of simazine, atrazine, promazine, prometon, desmetrine, amethrine, and terbutryn (75) (Table 5). Silica gel H, G, or LSL sorbents were investigated for the analysis of triazines in milk (76).
The separation of triazine herbicides was investigated on aminoplast, cellulose, and acetyl cellulose layers. All the ^-triazines investigated were resolved on different layers, but aminoplast gave the lowest limit of detection (76a) (Table 5).
Another detailed investigation was carried out on the separation of s-triazines and phenylurea herbicides. The optimization of the mobile phase was achieved by the ELUO method for their OPLC separation, and the following two-component solvent systems were studied: diethyl ether-ben-zene, diethyl ether-dichloromethane, dichloromethane-ethyl acetate, chloroform-ethyl acetate. These compounds were mixed in (9:1), (7:3), (1:1), (3:7), (1:9) ratios. The elution strength of all the solvents was calculated. The ELUO and PRISMA optimization methods were also compared (76b) (Table 5).
Silica gel G and GF254 (12,74) stationary phases were applied in water analysis (Table 5). In studies on the reversed-phase TLC of these compounds, a good correlation was found between the organic solvent content of the mobile phase and Rm values: the higher the organic solvent ratio, the
Cl OCH3
RNh/ N \HR2 R1 NH N NHR* NN|)R2
XIV
XV
XVI
Figure 4 Triazines, X1V-XVI. R1, R2: -alkyl, i-alkyl
Table 5 Triazines
Compound
Stationary
phase
Mobile phase
Six triazine
Simazine
Atrazine
Promazine
Prometon
Desmetryne
Ametryne
Terbutryne
Chloridazon
Bentazon
Atrazine
Simazine
Prometryne
Propazine
Simazine
Atrazine
Prometryne
Simazine
Atrazine
Propazine
Silica gel
Zn carbonate
Silica gel H
Silica gel G
Silica gel LSL Kieselgel G Kieselgel GF25J
(a) Kieselgel 60 F;5, (Merck)
(b) RPTI C V( paraffin oil in hexane
Hexane-butyl acetate (60:40)
(1) Benzene
(2) Benzene-acetone (98:2)
(3) Benzene-acetone (95:5)
(4) Benzene-acetone (92 :8)
(1) Toluene-acetone
(85: 15)
(2) Benzene-CHCl,-EtOAc
(2:2:1)
(1) Butylacetate-fl-hexane
(30:70)
(2) Ben/ene-CHCli-acetic
acid (40:40:20)
(1) H,0-Me0H-|a-
cyclodextrine (20: 10:2)
(2) H;0-MeC)H-/3-eyclo-
dextrine-LiCIH-O
(20:10:2:27)
(1)
6
15
20
0
4
8
10
20
7
46
39
63
56
20
37
43
(a-1) 71
64
s
Limit of detection
Rf x 100 Detection <Mg)
(2) (3) (4) Fluorescence (a) (b)
quenching
23 40 46 (a) UV 0.5 0,05
36 58 64 (b) 0.1 N AgNO, 1.0 0.10
52 77 84 in 3 N HNO, 1.0 0.10
7 11 2.0 0.50
12 21 28 0.5 0.50
19 33 45 0.5 0.50
31 51 64 0.5 0.50
Cl2. (Molidine 0.1-
AgNO,
lb
30 AgNO, 0.1 Water 12
42 UV 0.2
60 0.1
(b-2)
80 78
39
21
istlcldes
Table 5 (continued)
Compound
Stationary
phase
Mobile phase
Terbuthylazine
Trietazine
Atraton
Prometone
Etazine
Ametryne Prometryne Terbutryne Five other subst.
derivs.
Atrazine
Simazine
Ametryne
Atraton
Atrazine
HO-atrazine
Prometryne
Prometon
Propazine
(3) MeOH-/3-cyclodextrine (15:2)
Silica gel G
K4 (Whatman or Analtech), predevelopment CHCI MeOH (1:1) and impregnation with AgNO,-NH40H
(a) Kieselgel HF2M
(b) Kieselgel HF254
impregnated with 5% paraffin in hexane
CHCb-acetone (9:1)
(1) Benzene-MeOH (3:2)
(2) Me0H-H20 (1:1)
(3) MeOH-1 N NaCI (1:1)
68
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