20 30 40

Т i me С m i n . )

50

Figure 14.6: Separation of polar agro-chemicals in spiked Rhine river water. For peak identification, see Table 14.1, page 258.

lYends and concerns 14

257

1. aniline

2.carbendazim

3. l-(3-chloro-l-hydroxyphenyl)- 3,3-dimethylurea

4. metamitron

5. chloridazon

6. dimethoate

7. monomethyl metoxuron

8. aldicarb

9. bromacil

10. cyanazine

11. 2-nitrophenol

12. chlorotoluron

13. atrazine

14. diuron

15. metabromuron

16. metazachlor

17. propazine

18. warfarin

19. 3,3-dichlorobenzidine

20. barban

21. alachlor

22. nitralin

23. dinoseb

24. dinoterb

25. phoxim

26. nitrofen

27. trifluralin

Table 14.1: Herbicides and pesticides in Rhine water and tap water.

For some selected solutes, even lower detection levels are possible, as illustrated by the match between the UV-VIS library spectrum and the spectrun obtained from 0.1 ppb of atrazine in a spiked Rhine water sample shown in Figure 14.7.

258

14 Trends and concerns

100 ML OF RHINE WRTER С 13-3-1992, LOBITH) SPIKED WITH MIXTURE OF 2? PESTICIDES, С - 0.1

3

I

E

2001

180:

160:

14B:

120:

100

80:

B0:

40:

20:

0:

		UV	27.ЭЭЭ 28. 172	RTRRZINE CH) of 10
D гг	200-:	л	SPECTRHL	MRTCH	994
E	100-:	n
	200 Wave		1 ength	Cnm)	402

20 T 1 me

30 (mln.

50

Figure 14.7: O.lppb of atrazine in a spiked Rhine water sample and UV-Vis spectrum.

This can lead to the possibility for monitoring drinking water, according to the European Community (EC) concentration limits of O.lppb for individual and 0.5ppb for total pesticides. Figure 14.8 gives a glimpse of a tap water sample spiked with 27 components at low level concentrations.

Trends and concerns 14

259

II

id и

Ш

200:

180:

160-i

140:

120:

100:

80:

60:

40-:

20:

0:

-20:

нкД

00 ML OF TBP WRTER (9-4-1992, RMSTERDRM) SPIKED WITH MIXTURE OF 2? PESTICIDES

10

40

50

20 30

Ti meС m i n .

Figure 14.8: Tap water sample spiked with 27 components at low level concentrations.

Both SAMOS GC/MSD and SAMOS LC/MS can possibly detect lower concentration levels, because of superior sensitivity of mass spectroscopic detection, especially in the ion monitoring mode. In the LC/MS system, a particle beam interface may be used for the structural elucidation of unknowns, while maximum sensitivity for the analysis of target compounds is achieved with either the thermospray or electrospray interfaces.

The HP 7686 PrepStation is a new instrument designed to integrate sample preparation, analysis and data management. Capable of working with either HPLC or GC applications, the PrepStation is depicted in Figure 14.9 mounted on a gas chromatograph.

260

14 Trends and concerns

HP 7673B Injector

HP 7673B Tray

HP G1296A Mixer/Bar Code Reader

HP 7686 PrepStation

HP 5890 Series It ^ Gas Chromatograph

Figure 14.9: The HP 7686 PrepStation.

The sample preparation modules work in conjunction with the vial transport arm of the HP 7673 autosampler, allowing vials to be transferred to the PrepStation, where the different stages of sample preparation are performed. Two modules are available, the basic module and the solid phase extrac­tion/filtration module, both of which are equipped with a combination mixing device/bar code reader. Table 14.2 provides a list of all the sample preparation functions that may be performed using the PrepStation.

Trends and concerns 14

261

Function Applied for

* Basic Module

Dispensing/aspirating Dilution (linear or serial)

Internal standard addition Liquid transfer

Preparation of calibration standards pH adjustment

Evaporatioii/gaspurge Solvent removal

Blowdown and drying Concentration Inert gas blanket

Healing Dcrivalizatioii

Digestion

* SFE / nitration Module (includes all die functions of the basic module plus )

SPE Selective enrichment

Paniculate removal Filtration

* Bar-code reader/mixer module

Mixing Hoinogcnizalion

Blending Solid liquid extraction

Bar-code reading Sample tracking

Sample identification

Table 14.2: Sample preparation functions of the HP 7686 PrepStation.

By chaining different functions together, complete sample preparation methods can be automated, for example, the analysis of micropollutants by selective solid phase extraction followed by derivatization, liquid-liquid fractionation, solvent exchange and cool on-column injection can be performed as one 'method'. The system's multitasking software allows optimization of tasks, using the time a sample is being chromatographed to prepare the next sample, this 'just-in-time' preparation having the added advantage that every sample has exactly the same preparation history.

The latest trends in instrument development will definitely assist analysts who work in compliance with good laboratory practice (GLP) and good automated laboratory practice (GALP). Ideally, environmental contract laboratories should operate under GLP and the ISO-norms. Most countries have an official organisation responsible for monitoring and maintaining laboratory standards

262

14 Trends and concerns

and they may be contacted by laboratories wishing to receive accreditation. Quite recently 2 official organisations have been set up for the coordination and the harmonization of laboratory accreditation in Europe. These are the Western European Calibration Cooperation (WECC) and the Western European Laboratory Accreditation Cooperation (WELAC). Both bodies aim at ensuring the quality and traceability of measurement and test results in industry and trade, and apply European Standards EN45001 and ISO/IEC Guide 25 criteria to accredit laboratories. Accreditation based upon those criteria certify quality system and procedures as well as the technical ability of the laboratory to execute a precise task. Verifications include the laboratory's staff qualification, analytical methods' precision and accuracy and the availability of standard operating procedures and their implementation, for example. WELAC has a contact person available in most European countries and the following list is given, with the courtesy of NAMAS.

Austria

Dr Eva Dolak

Bundesministerium fur

Wirtschaftliche Angelegenheiten

HaupstralSe 55-57

A-1031 Wien

Tel: [phone]

Fax: [phone]

Belgium

Dr G V Merken Organisation Beige des Laboratoires d'Essais (BELTEST) Ministerie van Ekonomische Zaken Central Laboratorium Rue de la Senne 17A B-Bruxelles 1000 Tel: [phone] Fax: [phone]

Denmark

Mr К Т Jakobsen

Danish Accreditation Service (DANAK)

National Agency of Industry & Trade

137, Tagensvej

DK-2200 Copenhagen

Tel: [phone]

Fax: [phone]

Finland

Dr T Hattula

Centre for Metrology & Accreditation

(FINAS)

PO Box 239 (Lonnrotinkatu 37)

SF-0018 I Helsinki

Tel: [phone]

Fax: [phone]

Trends and concerns 14

263

France

Mr R Lavergne

RNE Secretariat Permanent

Reseau National d'Essais

77 rue du Pere Corentin

F-75014 Paris

Tel: [phone]

Fax: [phone]

Germany

Dr В Steffen

Deutscher Akkrediterungs Rat (DAR)

Bundesanstalt fur Materialforschung

und -priifung (BAM)

Unter den Eichen 87

D-12205 Berlin

Tel: [phone]

Fax: [phone]

Greece

Mrs M Pitsika

Hellenic Organisation for

Standardisation (ELOT)

313 Acharnon Street

GR-11145 Athens

Tel: [phone]

Fax: [phone]