5.3 General Procedure

Analytes are enriched by solid phase extraction (SPE) and analysed simultaneously by capillary gas chromatography - nitrogen phosphorus detection (CGC/NPD) and capillary gas chromatography - electron capture detection (ECD).

5.4 Sensitivity

5-70ng/l

Individual compounds are listed in Table 5.1.

Compound Detector Detection Recovery Std. Dev. Compound

Limit (ngA) (%) (±%) no. (figures)

Pentachlorobenzene	ECD	25	42	3	1
Trifluralin	ECD	25	90	13	2
alpha-HCH	ECD	25	86	13	3
Hexachlorobenzene	ECD	25	52	5	4
beta-HCH	ECD	25	88	9	5
gamma-HCH	ECD	25	93	9	6
delta-HCH	ECD	25	78	10	7
Alachlor	ECD	25	88	10	10
Heptachlor	ECD	25	74	16	11
Aldrin	ECD	25	63	10	13
cis-Heptachlorepoxide	ECD	25	99	10	14
trans-Heptachlorepoxide	ECD	25	86	6	15
trans-Chlordane	ECD	25	69	22	16
o,p-DDE	ECD	25	55	7	17
alpha-Endosulfan	ECD	25	86	11	19
cis-Chlordane	ECD	25	72	13	20
p,p-DDE	ECD	25	43	10	21
Dieldrin	ECD	25	98	12	22
o,p-DDD	ECD	25	71	7	23
Endrin	ECD	25	100	9	24

Table 5.1: Quantitative data in the analysis of halogenated pesticides, PCBs, PBrBs and phosphoric acid esters.

128

5 Pesticides, PCBs and PBrBs

Phenols

6.1 Introduction

The environmental aspects of phenolic compounds have become increasingly important in recent years and both the US EPA and the EC have included phenols on their priority pollutants lists. Phenols in water are routinely monitored by using either high pressure liquid chromatography (HPLC) or capillary gas chromatography with mass spectroscopic detection (CGC/MS).

6.2 Compounds
2-chlorophenol	(EC)	2 -ethylphenol
3-chlorophenol	(EC)	3-ethylphenol
4-chlorophenol	(EC)	2,3 -dimethylphenol
2,3-dichlorophenol		2,5 -dimethylphenol
2,4 -dichlorophenol		2,6 -dimethylphenol
2,6 -dichlorophenol		3,4 -dimethylphenol
3,4 -dichlorophenol		3,5 -dimethylphenol
3,5 -dichlorophenol		2 -chloro- 5 -methylphenol
2,3,4 -trichlorophenol	(EC)	4 -chloro- 2 -methylphenol
2,3,5-trichlorophenol	(EC)	4 -chloro- 3 -methylphenol
2,3,6-trichlorophenol	(EC)	2,4 -dibromophenol
2,4,5-trichlorophenol	(EC)	2,6 -dibromophenol
2,4,6 -trichlorophenol	(EC)	2,4,6-tribromophenol
4,6 -dichlororesorcin		2,3,5,6 -tetrachlorophenol

(EC)

2,3,4,5-tetrachlorophenol pentachlorophenol (EC)

(EC) Included on the European Community Priority Pollutants list.

Phenols 6

141

6.3 General Procedure

Phenols are extracted by liquid-liquid or solid phase extraction (SPE) after conversion to their acetates and analysed by capillary gas chromatography/mass spectroscopy (CGC/MS). Alternatively, phenols can be extracted without prior derivatization and analysed by HPLC/diode-array UV detection.

6.4 Sensitivity

5-20ppt by routine CGC/MS. > lppbbyHPLC.

6.5 Detailed Procedures

6.5.1 Procedure 1: Solid phase extraction/CGC/MS

Materials

• Chemicals

• phenol reference compounds

• 2,4,6-trichlorophenol-¹³C_G

• acetic anhydride, 99%

• potassium carbonate, p.a.

• sodium thiosulphate pentahydrate, p.a.

• acetone, p.a.

• methanol, p.a.

• water, HPLC-grade

• Solutions

• sodium thiosulphate pentahydrate in water (50 g/1)

• standard stock solution of reference substances in acetone (20mg/50ml per compound)

• working standards are prepared by appropriate dilution of the standard stock solution with acetone

working standard I 10 ug/ml working standard II 1 ug/ml

• internal standard

2,4,6-trichlorophenol-¹³Cfi in acetone (lug/ml)

142 6 Phenols

Anilines and nitroaromatics