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Appendix C: Commonly used analytical methods



C1. Commonly used analytical methods

The following Table gives details of the commonly used analytical methods for a range of determinants described in main body of the report. Also given is an indication of the limits of detection (LoDs) and precision that are quoted for the methods in the referenced texts. In addition, for some substances LoD’s that can be routinely achieved in good analytical laboratories (by gas-chromatography mass-spectrometry techniques) are given in brackets. The Tables should be used as a guide when aggregated monitoring data are assessed during the implementation phase of the proposed networks. Also given as examples are references for standard methods drawn up by the UK’s Standing Committee of Analysts (SCA). There are of course international organisations such as the European Standardisation Committee (CEN) and the International Standards Organisation (ISO) producing similar standard methods which would be equally relevant.


Table C.1 Commonly used analytical methods

Determinant

LoD

Precision

Methods

water temperature

 

+/- 0.08oC (Pt resist)

All waters - liquid in glass thermometer, thermocouple, resistance thermometer, typically used, (20).

pH

n/a

function of equipment used

Fresh/marine/river/ lake waters - Electrochemical potential of a cell which is responsive to the hydrogen ion activity and which contains the test solution analyte (4).

conductivity

Depends on cell construction

1.5%

Fresh/Marine/Lake/River waters - Electrical resistance of the sample in a cell of known dimensions (4).

dissolved oxygen

0.08-0.46 mg L-1

0.5-5%

Fresh/marine/lake/river waters - titrimetric method - DO in solution oxidises freshly precipitated manganous hydroxide. Acidification in the presence of iodide liberates iodine in stochiometric equivalence to DO content. The free iodine is measured titrimetrically (5).

colour

   

River/lake/fresh waters - the colour difference between a filtered water sample and a deionised water is determined by transmission measurement (400-700nm) in CIELAB units - can be converted to CHUs if required (26).

suspended matter

2 mg L-1

5-10%

Fresh/river/lake/marine waters - Filtration through pre-weighed glass fibre filter/ drying and weighing (14, 37)

turbidity

0.1 NTU

<3%

All waters - Nephelometric method using formazine suspensions as primary standards (36).

Table C.1 contd

Determinant

LoD

K

0.08 mg L-1

4%

Fresh/river/lake waters - flame photometry (9)

Mg

0.06 mg L-1

<5%

Fresh/river/lake waters - Acidified sample, treated with lanthanum salt and aspirated into flame AAS (38) also Ion Chromatography.

Na

0.03 mg L-1

1%

Fresh/river/lake waters - flame photometry (8)

Cl

   

All waters - Conductivity

SO4

0.1 mg L-1

0.1 mg L-1

2 mg L-1

<10%

<5%

<10%

All waters - ICP-OES, 180.73nm (32)

- Ion chromatography (32)

- Automated methylthymol blue colorimetric (32)


Table C.1 contd

Determinant

LoD

Precision

Methods

aluminium

0.01-0.1 mg L-1

13 mg L-1

0.5-3%

1-20%

Fresh/River/Lake waters - ICP-MS (2)

- Pyrocatechol violet/colorimetry (6)

total phosphorus

0.003 mg L-1

 

40 m g L-1

<1%

 

<5%

All waters - various pretreatments e.g. persulphate, followed by molybdate spectrophotometry as for phosphate (33).

All waters - ICP-OES (33)

PO4P

0.003 mg L-1

<1%

All waters-Phosphomolybdenum blue - continuous flow spectrophotometry (33).

Kjeldahl nitrogen

0.093 mg N L-1

1-10%

River/lake/fresh/marine waters - digestion with conc. sulphuric acid/peroxide, dilution and determination of ammonia by continuous flow (23)

oxidised nitrogen

0.02-0.56 mg L-1

0.02 -36 mg L-1

1-5%

1-5%

Saline waters-Copperised Cd/continuous flow spectrophometry

River/lake/fresh waters - Cu/hydrazine continuous flow (11)

ammoniacal nitrogen

0.009 mg L-1

0.0013 mg L-1

0.5-3%

0.5-3%

Fresh/River/Lake waters - continuous flow spectrophometry using salicylate or phenol/DIC

Marine waters - continuous flow Phenol/DIC spectrophometry (12)


Table C.1 contd

Determinant

LoD

Precision

Methods

silica

0.03 mg L-1

0.01 mg L-1

2.5%

<5%

Fresh/River/Lake/Marine waters using molybdate/spectrophotometric determination (10)

All waters - ICP-OES (33)

chlorophyll a

ca. 1 mg L-1

ca. 10%

Fresh/river/lake/marine waters - Extraction of pigment into organic solvent (acetone or methanol) - spectrophotometry/fluorimetry (17).

Secchi disc transparency

n/a

n/a

All water - visually detectable turbidity (36).

cadmium

0.01-0.1 m g L-1

0.1 m g L-1

0.5-3%

5-10%

Fresh/lake/river waters - ICP-MS (2)

Fresh/Lake/river waters - GF-AAS (21)

chromium

0.01-0.1 m g L-1

0.44-7.4 m g L-1

0.5-3%

1-5%

Fresh/River/Lake waters - ICP-MS (2)

- GF AAS (7,30)

copper

0.01-1 m g L-1

0.52 m g L-1

0.5-3%

<5%

Fresh/lake/river waters - ICP-MS (2)

- GF-AAS (30)

iron

0.1-10 m g L-1

0.5-3%

Fresh/lake/river waters - ICP-MS (2)

mercury

2 ng L-1

10% at 25 ng L-1

Fresh/Marine/Lake waters - cold vapour AAS (3)

manganese

5 m g L-1

1-5%

 

Table C.1 contd

Determinant

LoD

Precision

Methods

nickel

0.01-0.1 m g L-1

1.0 m g L-1

0.5-3%

<10%

Fresh/lake/river waters - ICP-MS (2)

- GF-AAS (30)

lead

1.0 m g L-1

0.01-0.1 m g L-1

3-20%

1-5%

Fresh/lake/river waters - Solvent extraction AAS (1), GF-AAS (21)

- ICP-MS (2)

zinc

0.01-0.1 m g L-1

2 m g L-1

0.5-3%

<5%

Fresh/lake/river/marine waters - ICP-MS (2)

- Flame AAS (31)

solvents

- PAH


- PCB

- chlorophenols

- organo-Cl-pesticides

 

0.02-0.2 m g L-1

 

1-2 ng L-1

0.1-0.9 mg L-1

0.021-0.1 m g L-1

 

5-10%

 

4% at 10 ng L-1

1-5%

<10%

 

Fresh/lake/river waters - phenanthrene/naphthalene pentane extraction/floisil clean-up, GC-FID (22)

Fresh/lake/river waters - Extraction with cyclohexane HPLC-fluorimetry (23) - routine method

Fresh/lake/river waters-Solvent extraction/derivatisation-GC (13)

Fresh/lake/river waters-deriv with PFB esters/extraction GC-ECD (25)


Table C.1 contd

Determinant

LoD

Precision

Methods

Trifluralin

1-2 ng L-1

<10%

Fresh/river/lake waters - Extraction with cyclohexane HPLC-fluorimetry (23) - routine method

Endosulfan

   

River/lake/fresh waters - Extraction into hexane, column clean up GC-ECD (34). Also GC-MS

Simazine

6.8 m g L-1

(5 ng L-1)

 

DCM extraction GC-ECD (39). Also GC-MS (43).

Atrazine

2.4 m g L-1

(5 ng L-1)

 

DCM extraction GC-ECD (39) Also GC-MS (43).

Azinphos ethyl

<01 m g L-1

(10 ng L-1)

 

River/lake/fresh waters - Hexane/DCM extraction GC-MS

Azinphos methyl

<0.1 m g L-1

(10 ng L-1)

 

River/lake/fresh waters - Hexane/DCM extraction GC-MS

Fenitrothion

0.03 m g L-1

10-20%

River/lake/fresh waters - extraction into hexane or DCM - GC-FPD (15). Also GC-MS (43).

Fenthion

   

All waters- Extraction GC-TID, or GC-MS.


Table C.1 contd

Determinant

LoD

Precision

Methods

Malathion

0.13 m g L-1

(5 ng L-1)

10-20%

River/lake/fresh waters - extraction into hexane or DCM - GC-FPD (15). Also GC-MS (43).

Parathion

0.1 m g L-1

(10 ng L-1)

10-20%

River/lake/fresh waters - extraction into hexane or DCM - GC-FPD (15) also GC-MS (43).

Parathion methyl

<0.1 m g L-1

(10 ng L-1)

 

River/lake/fresh waters - Hexane/DCM extraction GC-MS

Dichlorvos

0.04 m g L-1

10-20%

River/lake/fresh waters - extraction into hexane or DCM - GC-FPD (15) Also GC-MS (43).

Drins

3-14 ng L-1

 

3-14 ng L-1

up to 50%


ca. 50%

Turbid river/lake/fresh water samples - extraction with ethyl acetate, hexane, clean up using alumina-silver nitrate, column chromatography/GC-ECD (19).

River/lake/fresh waters - Extraction into hexane, column clean up GC-ECD (34).

DDT

15 ng L-1

 

15 ng L-1

(5 ng L-1)

up to 50%


up to 50%

Turbid river/lake/fresh water samples - extraction with ethyl acetate, hexane, clean up using alumina-silver nitrate, column chromatography/GC-ECD (19).

River/lake/fresh waters - Extraction into hexane, column clean up GC-ECD (34).

(Each individual isomer)


Table C.1 contd

Determinant

LoD

Precision

Methods

Chloridazon

<0.1 m g L-1

 

All waters extraction with polar solvent - or solid phase extraction, HPLC-UV detection (43).

Cyanazine

20 m g L-1

 

All waters - DCM extraction column switching HPLC-UV detection (43).

1,3-dichloropropene

<0.1 m g L-1

 

All waters - Purge and trap GC-MS (43, 44).

Diuron

0.7 m g L-1

0.05 m g L-1

<10%

 

All waters - Liquid/liquid extraction - filament off LC-TSP-MS (43).

Also solid phase extraction LC-UV (43).

Dimethoate

<0.1 m g L-1

 

All waters - Extraction GC-MS (43).

Disulfoton

0.3

Determinant

LoD

Precision

Methods

Metholachlor

0.7 m g L-1

 

All waters - DCM extraction - GC-NPD (40)

Metoxuron

<0.1 m g L-1

 

Extraction (methanol/acetonitrile) -HPLC (43).

Mevinphos

5 m g L-1

 

All waters - DCM extraction - GC-NPD (40)

Propachlor

0.5 m g L-1

 

River/lake/fresh waters - DCM extraction, solvent substitution with MTBE - GC-ECD (41)

Trichloroethylene

1.0 m g L-1

ca. 10%

River/lake/fresh waters - headspace GC-ECD (22)

Tetrachloroethylene

1.6 m g L-1

ca. 10%

River/lake/fresh waters - headspace GC-ECD (22)

Trichlorobenzene

 

<0.1 m g L-1

(50 ng L-1)

<20%

All waters - Extraction clean up - GC-ECD or GC-MS

(Each isomer)

1, 2 Dichloroethane

<1 m g L-1

<20%

All waters - cryogenic trapping GC-ECD.

1,1,1,- Trichloroethane

0.6 m g L-1

ca. 10%

River/lake/fresh waters - headspace GC-ECD (22)

Dioxins

ca. 0.01 ng L-1

ca. 20%

River/lake/fresh waters - extraction-GC-MS.

HCH

12 ng L-1

 

12 ng L-1

(1 ng L-1)

up to 50%

 

up to 50%

Turbid river/lake/fresh water samples - extraction with ethyl acetate, hexane, clean up using alumina-silver nitrate, column chromatography/GC-ECD (19).

River/lake/fresh waters - Extraction into hexane, column clean up GC-ECD (34).

(Each isomer)


Table C.1 contd

Determinant

LoD

Precision

Methods

HCB

0.6 ng L-1

20%+

River/lake/fresh waters -separation of HCB by column chromatography-capillary GC-ECD (19)

Carbon tetrachloride

0.13 m g L-1

ca. 10%

River/lake/fresh waters - headspace GC-ECD (22)

Chloroform

0.66 m g L-1

ca. 10%

River/lake/fresh waters - headspace GC-ECD (22)

PCP

0.08 m g L-1

 

River/lake/fresh waters - hydrolysis at pH 12, solvent wash, acidification, extraction into diethyl ether, derivatise with diazomethane - GC-ECD (42).

TBT

1 ng L-1

4 ng L-1

30% at LOD

All waters - derivatisation (sodium borohydride) GC-AAS

Solvent extraction AAS (total organic tin)

Also GC-MS (43).

TPT

1ng L-1

30% at LOD

All waters - derivatisation (sodium borohydride) GC-AAS

Also GC-MS (43).

total coliform

   

All waters - No./100ml multiple test tube

- No./100ml membrane filtration

faecal coliform

   

All waters - No./100ml multiple test tube

- No./100ml membrane filter


Table C.1 contd

Determinant

LoD

Precision

Methods

faecal streptococci

   

All waters - No./100ml multiple tube fermentation

- No./100ml membrane filter

Salmonella

   

River/lake/fresh/marine waters - ="JUSTIFY">(1) SCA blue book method: Lead in potable waters by atomic absorption spectrometry - 1976

(2) Manufacturers data - Environmental Analysis Applications of ICP-MS in the water industry. VG elemental, Technical information PQ 701.

(3) Blake S. (1985) Method for the determination of low concentrations of mercury in fresh and saline waters. Water research Centre TR 229, WRc, Henley Rd, Marlow, SL7 2HD, UK.

(4) SCA ‘blue book’ method: The measurement of electrical conductivity and the laboratory determination of the pH value of natural, treated and waste waters, HMSO, 1978.

(5) SCA ‘blue book’ Dissolved oxygen in natural and waste waters - 1979, HMSO, UK.

(6) SCA ‘blue book’ Acid soluble aluminium in raw and potable waters by spectrometry, 1979, HMSO, UK.

(7) SCA ‘blue book’ Chromium in raw and potable waters and sewage effluents, 1980, HMSO, UK.

(8) SCA ‘blue book’ Dissolved sodium in raw and potable waters - tentative methods, 1980, HMSO, UK.

(9) SCA ‘blue book’ Dissolved potassium in raw and potable waters - tentative methods, 1980, HMSO, UK.

(10) SCA ‘blue book’ Silicon in waters and effluents, 1980, HMSO, UK.

(11) SCA ‘blue book’ Oxidised nitrogen in waters, 1981, HMSO, UK.

(12) SCA ‘blue book’ Ammonia in waters, 1981, HMSO, UK.

(13) SCA ‘blue book’ Phenols in waters and effluents by GC, 4 aminoantipyrine or 3-methly-2-benzothiazolinone hydrazone, 1981, HMSO, UK.

(14) SCA ‘blue book’ Suspended, settleable and total dissolved solids in waters and effluents, 1980, HMSO, UK.

(15) SCA ‘blue book’ Organo-phosphorus pesticides in river and drinking water, 1980, HMSO, UK.

(16) SCA ‘blue book’ Methods for the isolation and identification of salmonellae (other than salmonella typhi) from water and associated materials, 1982, HMSO, UK.

(17) SAC ‘blue book’ The determination of chlorophyll a in aquatic environments, 1980, HMSO, UK.

(18) SCA ‘blue book’ Measurement of alpha and beta activity of water and sludge samples, 1985-1986, HMSO, UK.

(19) SCA ‘blue book’ Chlorobenzenes in water, organochlorine pesticides and PCBs in turbid waters, halogenated solvents and related compounds in sewage sludge and waters, 1985, HMSO, UK.

(20) SCA ‘blue book’ Temperature measurement for natural, waste and potable waters and other items of interest in the water and sewage disposal industry, 1986, HMSO, UK.

(21) SCA ‘blue book’ Lead and Cadmium in Fresh waters by atomic absorption spectrophotometry (second edition), 1986, HMSO, UK.

(22) SCA ‘blue book’ Determination of very low concentrations of hydrocarbons and halogenated hydrocarbons in waters, 1984-5, HMSO, UK.

(23) SCA ‘blue book’ The determination of 6 specific polynuclear aromatic hydrocarbons in waters, 1985, HMSO, UK.

(24) SCA ‘blue book’ Kjeldahl nitrogen in waters, 1987, HMSO, UK.

(25) SCA ‘blue book’ The determination of microgram and submicron amounts of individual phenols in rivers and potable waters, 1988, HMSO, UK.

(26) SCA ‘blue book’ The determination of colour of waters and wastewaters. A supplement, 1988, HMSO, UK.

(27) SCA ‘blue book’ 5 day biochemical oxygen demand - second edition, 1988, HMSO, UK.

(28) SCA ‘blue book’ Determination of radioactivity in water by multinuclide gamma ray spectrometry, 1989, HMSO, UK.

(29) SCA ‘blue book’ The determination of alkalinity and acidity in waters, 1981, HMSO, UK.

(30) SCA ‘blue book’ Sb, As, Be, Cr, Co, Cu, Ga, Ge, In, Ni, Se, Ag, Tl, V, Zn by electrothermal AAS, 1988, HMSO, UK.

(31) SCA ‘blue book’ Zinc in potable waters by atomic absorption spectrometry, 1980, HMSO, UK.

(32) SCA ‘blue book’ Sulphate in waters, effluents and solids, second edition, 1988, HMSO, UK.

(33) SCA ‘blue book’ Phosphorus and silicon in waters, effluents and sludges, 1992, HMSO, UK.

(34) SCA ‘blue book’ Organochlorine insecticides and PCBs in waters, 1978, HMSO, UK.

(35) SCA ‘blue book’ The instrumental determination of total organic carbon, total oxygen demand and related determinants, 1979, HMSO, UK.

(36) SCA ‘blue book’ Colour and Turbidity of waters, 1981, HMSO, UK.

(37) Yeats P.A. and Brugmann L. (1990) Suspended particulate matter, collection methods for gravimetric and trace metal analysis. International Council for the Exploration of the sea, No. 7, ISSN 0903-2606.

(38) SCA ‘blue book’ Li, Mg, Ca, Sr, Ba in waters and sewage effluents by AAS, 1987, HMSO, UK.

(39) EPA Method 505, USA.

(40) EPA Method 507, USA.

(41) EPA Method 508, USA.

(42) EPA Method 515.1, USA.

(43) Techniques and instrumentation in analytical chemistry - Vol 13. Environmental analysis, Techniques, applications, and quality assurance, edited by D Barcelo, Elsevier, ISBN 0-444-89648-1, 1993.

(44) EPA Method 524.2, USA.

 

 


   
 

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