Application
News
No.J118
Inductively Coupled Plasma Mass Spectrometry
Analysis of River Water by ICPMS-2030
LAAN-A-CP-E031
Q Introduction
The normal daily water consumption of adults is
thought to be around 2 liters, almost all of which
consist of drinking water such as tap water or mineral
water. Sources of this drinking water include river water
and ground water. Each country has regulations that
require testing of the safety and condition of river
water and ground water. Countries also stipulate
environmental standards for the protection of our living
environment that also require testing. These include
tests for high concentration elements such as sodium
and calcium that are present at 10 mg/L or higher, and
trace elements such as arsenic and lead that are present
at 10 μg/L or lower. We describe using Shimadzu's
ICPMS-2030 inductively coupled plasma mass
spectrometer to analyze river water for the presence of
these elements.
Q Sample
・River water reference material: JSAC 0301-3, 0302-3
p Instrument
Shimadzu's ICPMS-2030 inductively coupled plasma
mass spectrometer was used for analysis. In addition to
being highly sensitive, the ICPMS-2030 uses a helium
gas collision system that greatly reduces the spectral
interference caused by argon and chlorine. Use of Eco
mode and a mini-torch drastically reduces running costs
associated with gas usage, compared to previous ICP-
MS systems.
p Analysis
A calibration curve method was used to measure trace
amounts of 19 constituents: lead (Pb), chromium (Cr),
cadmium (Cd), selenium (Se), arsenic (As), copper (Cu),
Iron (Fe), manganese (Mn), zinc (Zn), boron (B),
aluminum (Al), nickel (Ni), barium (Ba), molybdenum
(Mo), uranium (U), potassium (K), sodium (Na),
magnesium (Mg), and calcium (Ca).
p Removal of Spectral Interference
(Collision System)
The sensitivity of ICP-MS is reduced by spectral
interferences arising from polyatomic ions and errors in
results are found. For water quality analysis, these
polyatomic ions include
40
Ar
16
O that interferes with
measurement of
56
Fe,
40
Ar
35
Cl that interferes with
measurement of
75
As, and
40
Ar
38
Ar that interferes with
measurement of
78
Se.
Fig. 1 and 2 show the calibration curves for Fe and Se
without using the collision system (No-Gas mode) and
while using the collision system (CC mode). The
collision system removes spectral interference, which
increases the detection limit.
p Analytical Results
Table 1 shows Japan's drinking water quality standards
and results obtained from analysis of river water
reference material. Good quantitative results were
obtained that matched the certified values, even when
analyzing trace concentrations that were below
reference values.
0 50
0
5000
10000
15000
Intensity
Fe 56 (3N)
0 50
0
250
500
750
1000
1250
Intensity
Fe 56 (2G)
Calibration Curve of
56
Fe (No-Gas Mode)
BEC = 97 μg/L Detection Limit = 2 μg/L
Calibration Curve of
56
Fe (CC Mode)
BEC = 0.3 μg/L Detection Limit = 0.04 μg/L
Concentration
(μg/L)
Concentration
(μg/L)
Fig. 1
56
Fe Calibration Curves
[References]
・Ministerial ordinance on water quality standards (Ministry of Health,
Labour and Welfare ordinance No. 101, May 30, 2003; Revised by
Ministry of Health, Labour and Welfare ordinance No. 15, February
28, 2014) [In Japanese]
・Methods determined by Minister of Health, Labour and Welfare
based on regulations of the ministerial ordinance on water quality
standards (Ministry of Health, Labour and Welfare notification No.
261, July 22, 2003; Revised by Ministry of Health, Labour and
Welfare notification No. 56, March 12, 2015) [In Japanese]
Internal reference standard elements (Co, Ga, Y, In, Tl)
were added to each sample to a concentration of 5 μg/L.
Since this study examines a tap water source, analysis
was performed based on the ministerial ordinance on
water quality standards issued by the Ministry of Health,
Labour and Welfare.
