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UK Upland Waters Monitoring Network

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UK UWMN Water Chemistry Methods

Water chemistry dip sampling, River Etherow

At all stream sites water samples for chemical analysis are collected monthly. At lake sites, where the chemistry is more stable, sampling is undertaken on a quarterly basis. All dip samples are collected in acid-rinsed bottles.

The chemical determinands recorded at each site are those recommended by the Acid Waters Review Group (Warren et al. 1986). Accuracy requirements were established in accordance with Water Research Centre (WRc) recommendations and UK water industry practice. The UK UWMN laboratories regulary participate in ICP Waters international water chemistry intercalibration exercises (eg. Hovind H., 2004; Hovind H., 2005; Hovind H., 2006; Hovind H., 2007; Hovind H., 2009; Dahl I. and Hagebo E., 2011; Dahl I., 2012; Escudero-Onate C., 2013; Escudero-Onate C., 2014). The more stable determinands are analysed at the Centre for Ecology and Hydrology, Lancaster. Those determinands which are considered to require prompt analysis are analysed at two local laboratories; Marine Scotland, Pitlochry and the Centre for Ecology and Hydrology, Bangor. To enhance efficiency and minimise disruption, the local laboratories follow their own routine analytical methods which have a proven performance record. The tables below summarise the methods utilised and detection limits for the analysis of each determinand.

Centre for Ecology and Hydrology Lancaster Methods and Detection Limits

Determinand Minimum Detection Limit (mg l -1) Method
Alkalinity   Dual end-point Gran titration. Mettler-Toledo DL53 autotitrator
Dissolved Organic Carbon 0.5 Shimadzu TOC-Vcph analyser
Ca 0.0029 Perkin Elmer DV 4300 ICP-OES
Mg 0.0010 Perkin Elmer DV 4300 ICP-OES
Na 0.0025 Perkin Elmer DV 4300 ICP-OES
K 0.0094 Perkin Elmer DV 4300 ICP-OES
Fe 0.0003 Perkin Elmer DV 4300 ICP-OES
Al 0.0024 Perkin Elmer DV 4300 ICP-OES
V 0.00002 Perkin Elmer DRCII ICP-MS
Cr 0.00004 Perkin Elmer DRCII ICP-MS
Mn 0.000006 Perkin Elmer DRCII ICP-MS
Fe 0.0003 Perkin Elmer DRCII ICP-MS
Co 0.000006 Perkin Elmer DRCII ICP-MS
Ni 0.00001 Perkin Elmer DRCII ICP-MS
Cu 0.000002 Perkin Elmer DRCII ICP-MS
Zn 0.001 Perkin Elmer DRCII ICP-MS
As 0.000008 Perkin Elmer DRCII ICP-MS
Se 0.000043 Perkin Elmer DRCII ICP-MS
Sb 0.00013 Perkin Elmer DRCII ICP-MS
Cd 0.000012 Perkin Elmer DRCII ICP-MS
Pb 0.000059 Perkin Elmer DRCII ICP-MS
Al 0.00059 Perkin Elmer DRCII ICP-MS

CEH Lancaster accredited to ISO/IEC 17025:2005. United Kingdom Accreditation Service (UKAS) laboratory details available here (pdf).

Marine Scotland Laboratory Methods and Detection Limits

Determinand Minimum Detection Limit (mg l -1) Method
pH   Radiometer TTT81
H+   Derived
Alkalinity   Radiometer TTT81
Conductivity   Conductivity Meter
TON 0.062 Ion Chromatography (Dionex ICS 1000)
PO4 0.001 Colourimetrically (Molybdate Ascorbic Acid)
Soluble Monomeric Al 0.003 Colourimetrically (Catechol Violet)
Soluble Non-Labile Monomeric Al 0.003 Colourimetrically (Catechol Violet)
Soluble Labile Monomeric Al 0.003 Derived by Difference
Dissolved Organic Carbon 1.000 Continous Flow Analyser
Ca 0.100 Ion Chromatography (Dionex DX120)
Mg 0.024 Ion Chromatography (Dionex DX120)
Na 0.023 Ion Chromatography (Dionex DX120)
NH4 0.018 Ion Chromatography (Dionex DX120)
K 0.039 Ion Chromatography (Dionex DX120)
SO4 0.048 Ion Chromatography (Dionex ICS 1000)
Cl 0.070 Ion Chromatography (Dionex ICS 1000)
Br 0.040 Ion Chromatography (Dionex ICS 1000)
Excess SO4   Derived

Marine Scotland accredited to ISO/IEC 17025:2005. United Kingdom Accreditation Service (UKAS) laboratory details available here (pdf).

Centre for Ecology and Hydrology Bangor Methods and Detection Limits

Determinand Minimum Detection Limit (mg l -1) Method
pH   Metrohm Auto-titration
H+   Derived
Alkalinity 0.001 Metrohm Auto-titration
Conductivity   Jenway 4320 Conductivity Meter
TON 0.013 Thermo-oxidation
PO4 0.004 Discrete Colorimetric (880 nm)
Dissolved Organic Carbon 0.200 Thermo-oxidation

References

Hovind H. International Cooperative Programme on Assessment and Monitoring of Acidification of Rivers and Lakes. Intercomparison 0418: pH,K25,HCO3, NO3+NO2, Cl, SO4, Ca, Mg, Na, K, Fe, Mn, Cd, Pb, Cu, Ni and Zn. 1-69. (2004). Oslo, Norway, NIVA.

Hovind H. International Cooperative Programme on Assessment and Monitoring of Acidification of Rivers and Lakes. Intercomparison 0519: pH, Cond, HCO3, NO3+NO2, C1, SO4, Ca, Mg, Na, K, Fe, Mn, Cd, Pb, Cu, Ni, and Zn. 1-70. (2005). Oslo, Norway, NIVA.

Hovind H. International Cooperative Programme on Assessment and Monitoring of Acidification of Rivers and Lakes. Intercomparison 0620: pH, Cond, HCO3, NO3+NO2, Cl, SO4, Ca, Mg, Na, K, Fe, Mn, Cd, Pb, Cu, Ni and Zn. 1-69. (2006). Oslo, Norway, NIVA.

Hovind H. International Cooperative Programme on Assessment and Monitoring of Acidification of Rivers and Lakes. Intercomparison 0721: pH, Cond, HCO3, NO3-N, C1, SO4, Ca, Mg, Na, K, Fe, Mn, Cd, Pb, Cu, Ni, and Zn. 1-68. (2007). Oslo, Norway, NIVA.

Hovind H. International Cooperative Programme on Assessment and Monitoring of Acidification of Rivers and Lakes. Intercomparison 0923: pH, Cond, HCO3, NO3-N, Cl, SO4, Ca, Mg, Na, K, TOC, Al, Fe, Mn, Cd, Pb, Cu, Ni, and Zn. 1-73. (2009). Oslo, Norway, NIVA.

Hovind H. International Cooperative Programme on Assessment and Monitoring of Acidification of Rivers and Lakes. Intercomparison 1024: pH, Cond, HCO3, NO3-N, Cl, SO4, Ca, Mg, Na, K, TOC, Al, Fe, Mn, Cd, Pb, Cu, Ni, and Zn. 1-77. (2010). Oslo, Norway, NIVA.

Dahl I, Hagebo E. International Cooperative Programme on Assessment and Monitoring of Acidification of Rivers and Lakes. Intercomparison 1125:pH, Conductivity, Alkalinity, NO3-N, Cl, SO4, Ca, Mg, Na, K, TOC, Al, Fe, Mn, Cd, Pb, Cu, Ni and Zn. 1-77. (2011). Oslo, Norway, NIVA.

Dahl I. International Cooperative Programme on Assessment and Monitoring of Acidification of Rivers and Lakes. Intercomparison 1226:pH, Conductivity, Alkalinity, NO3-N, Cl, SO4, Ca, Mg, Na, K, TOC, Al, Fe, Mn, Cd, Pb, Cu, Ni and Zn. 1-92. (2012). Oslo, Norway, NIVA.

Escudero-Onate C. International Cooperative Programme on Assessment and Monitoring of Acidification of Rivers and Lakes. Intercomparison 1327:pH, Conductivity, Alkalinity, NO3-N, Cl, SO4, Ca, Mg, Na, K, TOC, Al, Fe, Mn, Cd, Pb, Cu, Ni and Zn. 1-93. (2013). Oslo, Norway, NIVA.

Escudero-Onate C. International Cooperative Programme on Assessment and Monitoring of Acidification of Rivers and Lakes. Intercomparison 1428:pH, Conductivity, Alkalinity, NO3-N, Cl, SO4,Ca, Mg, Na, K, TOC, Al, Fe, Mn, Cd, Pb, Cu, Ni and Zn. 1-88. (2014). Oslo, Norway, NIVA.

Warren, S. C., Bache, B. W., Edmunds, W. M., Egglishaw, H. J., Gee, A. S., Hornung, M., Howells, G. D., Jordan, C., Leeming, J. B., Maitland, P. S., Pugh, K. B., Sutcliffe, D. W., Wells, D. E., Cape, J. N., Ellis, J. C., Hunt, D. T. E., Wilson, R. B. & Watson, D. C. (1986) Acidity in United Kingdom fresh waters. United Kingdom Acid Waters Review Group interim report. Department of the Environment, London.

Page last modified: 18th February, 2015
Page published: 12 March 2010