Metal analysis in water based on EPA method 200.8
The analytical methods described here allow for the quantitaion of dissolved or total elements in samples such as ground waters, surface waters, and drinking water. Analysis of appropriately prepared samples is conducted by inductively coupled plasma mass spectrometry (ICP-MS). The analytes shown in Table I constitute the usual suite of trace elements included in method 200.8 analyses; however, additional non-trace elements (such as calcium, iron, magnesium, potassium, sodium) may be determined in aqueous matrices as appropriate. For a full SOP click .
Table I. Typical suite of elements determined by EPA Method 200.8.
| Trace Elements EPA 200.8 Validated | Element Name | Element Symbol | LOD |
| Aluminum | Al | 0.8 |
| Antimony | Sb | 1.5 |
| Arsenic | As | 0.5 |
| Barium | Ba | 0.7 |
| Beryllium | Be | 0.04 |
| Cadmium | Cd | 0.5 |
| Chromium | Cr | 0.8 |
| Cobalt | Co | 2.0 |
| Copper | Cu | 1.5 |
| Lead | Pb | 0.4 |
| Manganese | Mn | 1.4 |
| Mercury | Hg | |
| Molybdenum | Mo | 0.8 |
| Nickel | Ni | 0.8 |
| Selenium | Se | 0.8 |
| Silver | Ag | 0.8 |
| Thallium | Tl | 1.0 |
| Thorium | Th | 0.8 |
| Uranium | U | 0.8 |
| Vanadium | V | 1.0 |
| Zinc | Zn | 0.7 |
| Non-Trace Elements
| Calcium | Ca | 70 |
| Iron | Fe | 20 |
| Magnesium | Mg | 20 |
| Potassium | K | 30 |
| Sodium | Na | 26 |
Internal standards (IS) contains Li6, Sc, Ge, Y, In, Tb, and Bi at 10 ppm for use as internal standards. Continuous calibration verification (CCV) and calibration blank verification (CB) are performed continuously during measurements (~ each 10th sample). International standard “NIST 1643” is measured at least each month.
Values measured for NIST standard 1643 and deviation from true value (%)
Table II true concentration and measured concentration of NIST 1643 standard (November 2007)
| Element | concentration | Measured n=4 | Dev |
| | μg/kg | μg/kg | % |
| Ag / 107 | 7.6 | 8.4 | 11 |
| Al / 27 | 52.0 | 51.8 | 0 |
| As / 75 | 26.7 | 26.0 | -3 |
| Ba / 137 | 148.0 | 145.2 | -2 |
| Be / 9 | 34.9 | 34.0 | -3 |
| Cd / 114 | 22.8 | 22.5 | -1 |
| Co / 59 | 20.3 | 20.5 | 1 |
| Cr / 52 | 38.6 | 34.3 | -11 |
| Cu / 63 | 85.2 | 84.3 | -1 |
| Fe / 56 | 34.3 | 42.3 | 23 |
| K / 39 | 994.0 | 1035.1 | 4 |
| Mn / 55 | 121.5 | 123.7 | 2 |
| Mo / 98 | 46.8 | 46.8 | 0 |
| Ni / 60 | 27.4 | 27.8 | 1 |
| Pb / 208 | 27.9 | 27.7 | -1 |
| Sb / 121 | 13.8 | 14.4 | 5 |
| Se / 78 | 22.0 | 18.8 | -14 |
| Th / 232 | Nd | | |
| Tl / 205 | Nd | | |
| U / 238 | Nd | | |
| V / 51 | 13.0 | 13.5 | 4 |
| Zn / 66 | 53.2 | 52.1 | -2 |
| | mg/kg | mg/kg | |
| Ca / 40 | 7.0 | 6.8 | 3 |
| Mg / 24 | 5.8 | 5.9 | 2 |
| Na / 23 | 29.4 | 30.3 | 3 |
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HCl-HNO3-H2O2 digests are performed following standard method SW 3050B. The elements are diluted 1:1000 or higher for measurement on ICPMS. Measurement is performed using internal standard and 7 level calibration (see 200.8). Blanks are recorded for each step of the digestion and dilution procedure.
Metal Analysis of total dissolved solutes in water:
This method is an acid digestion procedure used to prepare surface and ground water samples for analysis by inductively coupled argon plasma mass spectroscopy (ICP-MS) with reaction cell. The entire sample is acidified at the time of collection with nitric acid. At the time of analysis the sample is heated with acid and reduced in volume. The digestate is filtered and diluted to volume, and is then ready for analysis. Measurement is performed using internal standard and 7 level calibration (see 200.8). Blanks are recorded for each step of the digestion and dilution procedure.
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