U.S. Department of the InteriorU.S. Geological Survey

Fact Sheet 2016–3043June 2016

Elemental Analysis Using a Handheld X-Ray Fluorescence SpectrometerThe U.S. Geological Survey is collecting geologic samples from

local stream channels, aquifer materials, and rock outcrops for studies of trace elements in the Mojave Desert, southern California. These samples are collected because geologic materials can release a variety of elements to the environment when exposed to water. The samples are to be analyzed with a handheld X-ray fluorescence (XRF) spec-trometer to determine the concentrations of up to 27 elements, includ-ing chromium (see “Periodic Table of the Elements” on back page).

Why are These Data Collected?The purpose of the XRF data is to determine the presence and

concentration of elements in local geologic materials. These data are used for the following purposes:• As a screening tool to guide further data collection and detailed

mineralogic and chemical analyses.

• To evaluate whether the alluvial material composing local aquifers and the trace elements in that material are from a local or more distant source.

• For comparison with the known, average compositions of various soils, alluvium, and rocks to evaluate past and present processes that could act on the alluvium and release trace elements to groundwater.

• For comparison to local and regional water-quality data to deter-mine which of the elements present could be released into ground-water from natural rather than human sources.

How Does it Work?X-ray fluorescence spectrometry works by irradiating a sample

or external standard with an X-ray beam produced by passing an electrical current through an X-ray tube. The X-ray beam dislodges electrons from the inner shells of an element, causing electrons from the outer shells to cascade down to the inner shells to fill in the gaps. The cascading electrons emit energy (‘fluoresce’) at wavelengths that are unique to each element. A detector measures the energy generated by cascading electrons in the sample, producing a pattern (spectrum) similar to that in figure 1. A computer application matches the spectrum to known spectral patterns to calculate element concentrations in milligrams per kilogram (mg/kg). The instrument uses three different filter and electrical current settings, which are optimized for particular suites of elements.

40200Energy, in kiloelectronvolts

Beam 3Beam 2Beam 1

Raw data spectrum

Example data from a granitic sand

EXPLANATION800

400

0

Coun

ts p

er s

econ

d

Fluorescence(emitted energy)

Dislodged electronAtom in sample

Detector

Rock or soilsample

X-ray tube

Concentrations in milligrams per kilogram (mg/kg); ±, plus or minus; <, less than; –, data not available

ElementMeasured

concentration (mg/kg)

Precision (± mg/kg)

Average continental

crust (mg/kg)1

Antimony <13 – 0.2Arsenic 2.7 0.4 1Calcium 9,320 50 53,000Chromium 3.3 1.1 185Iron 2,980 14 7,060Lead 14 0.6 8Manganese 85 1.7 950Selenium 1.0 0.2 0.05Uranium <2.9 – 2

1Hitchon, B., Perkins, E.H., and Gunter, W.D., 1999, Introduction to ground water geo-chemistry: Alberta, Canada, Geoscience Publishing, Ltd., 310 p.

Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Geological Survey.

Figure 1. Basic X-ray fluorescence principles and example data table.

The handheld instrument (fig. 2) uses a 4-watt X-ray tube and is powered by a 7.2-volt lithium-ion battery. Samples either can be measured in place, after removing debris and large pebbles from the measurement area, or can be ground to a fine powder for analysis. Accuracy is verified through the routine measurement of standards that have known elemental compositions.

Figure 2. Handheld X-ray fluorescence spectrometer and external calibration standards.

For more information contact:Krishangi Groover (kgroover@usgs.gov) or John Izbicki (jaizbick@usgs.gov)U.S. Geological Survey California Water Science Center(619) 225-6100http://ca.water.usgs.gov/mojave/http://ca.water.usgs.gov/projects/hinkley/

ISSN 2327-6932 (online)http://dx.doi.org/10.3133/fs20163043

nitrogen

14.007

N7

helium

He4.0026

2

neon

Ne20.180

10fluorine

F18.998

9oxygen

O15.999

8carbon

C12.011

6boron

B10.811

5

argon

Ar39.948

18chlorine

Cl35.453

17sulfur

S32.065

16phosphorus

P30.974

15silicon

Si28.086

14aluminium

Al26.982

13

krypton

Kr83.798

36bromine

Br79.904

35selenium

Se78.96

34arsenic

As74.922

33germanium

Ge72.64

32gallium

Ga69.723

31zinc

Zn65.38

30copper

Cu63.546

29nickel

Ni58.693

28cobalt

Co58.933

27iron

Fe55.845

26manganese

Mn54.938

25chromium

Cr51.996

24vanadium

V50.942

23titanium

Ti47.867

22scandium

Sc44.956

21calcium

Ca40.078

20potassium

K39.098

19

magnesium

Mg24.305

12sodium

Na22.990

11

beryllium

Be9.0122

4lithium

Li6.941

3

hydrogen

H1.0079

1

xenon

Xe131.29

54iodine

I126.90

53tellurium

Te127.60

52antimony

Sb121.76

51tin

Sn118.71

50indium

In114.82

49cadmium

Cd112.41

48silver

Ag107.87

47palladium

Pd106.42

46rhodium

Rh102.91

45ruthenium

Ru101.07

44technetium

Tc[98]

43molybdenum

Mo95.96

42niobium

Nb92.906

41zirconium

Zr91.224

40yttrium

Y88.906

39strontium

Sr87.62

38rubidium

Rb85.468

37

radon

Rn[222]

86astatine

At[210]

85polonium

Po[209]

84bismuth

Bi208.98

83lead

Pb207.2

82

dysprosium

Dy162.50

66terbium

Tb158.93

65gadolinium

Gd157.25

64europium

Eu151.96

63samarium

Sm150.36

62promethium

Pm[145]

61neodymium

Nd144.24

60praseodymium

Pr140.91

59cerium

Ce140.12

58lanthanum

La138.91

57

barium

Ba137.33

56caesium

Cs132.91

55

roentgenium

Rg[272]

111darmstadtium

Ds[271]

110meitnerium

Mt[268]

109hassium

Hs[277]

108bohrium

Bh[264]

107seaborgium

Sg[266]

106dubnium

Db[262]

105rutherfordium

Rf[261]

104radium

Ra[226]

88francium

Fr[223]

87

lutetium

Lu174.97

71ytterbium

Yb173.05

70thulium

Tm168.93

69erbium

Er167.26

68holmium

Ho164.93

67

thallium

Tl204.38

81mercury

Hg200.59

80gold

Au196.97

79platinum

Pt195.08

78iridium

Ir192.22

77osmium

Os190.23

76rhenium

Re186.21

75tungsten

W183.84

74tantalum

Ta180.95

73hafnium

Hf178.49

72

berkelium

Bk[247]

97lawrencium

Lr[262]

103nobelium

No[259]

102mendelevium

Md[258]

101fermium

Fm[257]

100einsteinium

Es[252]

99californium

Cf[251]

98curium

Cm[247]

96americium

Am[243]

95plutonium

Pu[244]

94neptunium

Np[237]

93uranium

U238.03

92protactinium

Pa231.04

91thorium

Th232.04

90actinium

Ac[227]

89

Elements detectable with handheld X-ray fluorescence spectrometer

hydrogen

H1.0079

1Element name

SymbolAtomic weight

Atomic number

Lanthanides

Actinides

Periodic Table of the Elements