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 here.

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

Metal analysis in acid digests of sludge, soil and tissue:

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.