METHOD 200.5 DETERMINATION OF TRACE ELEMENTS IN DRINKING 

WATER BY AXIALLY VIEWED INDUCTIVELY COUPLED 

PLASMA - ATOMIC EMISSION SPECTROMETRY 

Revision 4.2

October 2003

Theodore D. Martin

NATIONAL EXPOSURE RESEARCH LABORATORY

OFFICE OF RESEARCH AND DEVELOPMENT

U. S. ENVIRONMENTAL PROTECTION AGENCY

CINCINNATI, OHIO 45268

200.5-1

EPA Document #: EPA/600/R-06/115
METHOD 200.5 

DETERMINATION OF TRACE ELEMENTS IN DRINKING WATER BY AXIALLY 

VIEWED INDUCTIVELY COUPLED PLASMA-ATOMIC EMISSION 

SPECTROMETRY 

1.0 SCOPE AND APPLICATION 

1.1 Axially viewed inductively coupled plasma-atomic emission spectrometry

(AVICP-AES) is used to determine trace elements, as well as water matrix elements, 

in drinking water and drinking water supplies. This method is applicable to the

following analytes: 

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Chemical Abstract Services 

Analyte Abbreviation Registry Numbers (CASRN) 

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Aluminum (Al) 7429-90-5 

Antimony* (Sb) 7440-36-0 

Arsenic* (As) 7440-38-2 

Barium* (Ba) 7440-39-3 

Beryllium* (Be) 7440-41-7 

Boron (B) 7440-42-8 

Cadmium* (Cd) 7440-43-9 

Calcium (Ca) 7440-70-2 

Chromium* (Cr) 7440-47-3 

Copper* (Cu) 7440-50-8 

Iron (Fe) 7439-89-6 

Lead* (Pb) 7439-92-1 

Magnesium (Mg) 7439-95-4 

Manganese (Mn) 7439-96-5 

Nickel (Ni) 7440-02-0 

Selenium* (Se) 7782-49-2 

Silica (SiO2) 7631-86-9 

Silver (Ag) 7440-22-4 

Sodium (Na) 7440-23-5 

Tin (Sn) 7440-31-5 

Vanadium (V) 7440-62-2 

Zinc (Zn) 7440-66-6 

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* Designated primary drinking water contaminant. 

1.2 For reference where this method is approved for use in compliance monitoring 

program (e.g., Safe Drinking Water Act [SDWA]) consult both the appropriate

sections of the Code of Federal Regulation (40 CFR Part 141 § 141.23) and the

latest Federal Register announcements. 

200.5-2
1.3 This method provides a specific procedure utilizing axially-viewed plasma atomic 

emission signals generated only by pneumatic nebulization for the analysis of all

analytes. Some AVICP-AES instruments are so configured that the emitted signal

can also be viewed alternately or simultaneously in a radial manner. Radiallyviewed signals for the determination of drinking water matrix elements (Ca, Mg and

Na) and silica are acceptable. The Ca and Mg data can be used in the calculation of

hardness. 

1.4 When viewing sodium emission from the axial configuration, the ratio of signal

intensity to analyte concentration is not a linear response. Therefore, sodium should 

be calibrated using multiple standard solutions of increasing concentration to

properly define the response ratio at various levels of concentration (see Sect. 7.8.2). 

1.5 For drinking water compliance monitoring, a “total” element determination 

(dissolved + suspended fractions) is required. When the measured turbidity on an

acid preserved sample is < 1 NTU, direct analysis, without sample digestion, is 

permitted with the use of some approved spectrochemical methods. However, when 

using this method, all samples are digested and preconcentrated prior to analysis

using the total recoverable digestion(1) step described in Section 11.1.

Preconcentrating the sample prior to analysis increases analytical sensitivity for 

meeting the method detection limit (MDL) requirements given in Section 1.12.

Thus, when using this method, the need to measure sample turbidity prior to metal 

analysis is eliminated. 

1.6 Operative matrix effects can occur from elevated dissolved solids. Using this

technique, matrix effects have been observed when the concentration of calcium 

and/or the combined concentrations of the matrix elements (Ca, Mg, and Na) and

silica exceed 125 mg/L and 250 mg/L, respectively. To verify that a matrix effect is 

not operative, an LFM (see Sect. 9.4) must be analyzed when a primary contaminant 

(see Sect. 1.1) concentration exceeds 80% of the established maximum contaminant 

level (MCL) or action level. If the absence of a matrix interference can not be 

verified, the sample must be analyzed by method of standard additions (MSA; see

Sect. 11.3) or another approved method (see Sect. 1.7 for special requirements for 

lead). 

1.7 When determining lead by this method, the instrument must be capable of analyzing

silica as well. Levels of silica that exceed 30 mg/L, when preconcentrated 2X,

cause a suppressive effect on lead determinations. For samples containing silica

above 30 mg/L and lead concentrations $ 10 μg/L, lead must be determined by 

method of standard additions (MSA; see Sect. 11.3) or by another approved 

compliance monitoring method. If the laboratory can not determine silica when 

using this method, this method can not be used for compliance monitoring of lead. 

1.8 When determining boron and silica, only plastic or PTFE labware should be used

from time of sample collection to completion of analysis. In this method, glassware

is specifically avoided and only the use of metal-free plastic labware is 

recommended. Borosilicate glass should be avoided to prevent contamination of 

these analytes. 

200.5-3
1.9 The total recoverable sample digestion procedure given in Section 11.1 is suitable

for the determination of silver in aqueous samples containing concentrations up to

0.1 mg/L. Also, samples prepared using the procedure may be analyzed for thallium

using EPA Method 200.9(2). 

1.10 Compliance monitoring data for metal contaminants are normally reported in units

of mg/L; however, the data for the total recoverable analytes in this method are 

noted in units of μg/L. This difference is done to reduce or eliminate the listing of

non-significant zeros. When data are reported for compliance monitoring, the data

should be reported in the same units used to express the established MCL and to the

appropriate numerical level of significance. 

1.11 MDLs for trace elements and linear ranges for the drinking water matrix elements 

will vary with the wavelength selected and the spectrometer configuration and

operating conditions. Table 4 provides determined MDLs for the listed wavelengths

utilizing the instrument operating conditions given in Table 3. These values are 

provided for comparative purposes for user self-evaluation when completing the 

mandatory initial demonstration of performance. Meeting the exact same limits 

listed in Table 4 is not necessarily a requirement for the use of this method. Users 

of this method must document and have on file the required initial demonstration 

performance data described in Section 9.2 prior to using the method for analysis

(see Sect. 1.12). 

1.12 Users of this method for the purpose of SDWA compliance monitoring must achieve 

and document MDLs for As, Be, Cd, Sb, Se, and Pb that are # a value of 1/5 their

respective MCL or action level. 

2.0 SUMMARY OF METHOD 

2.1 A 50 mL aliquot of a well-mixed, non-filtered, acid preserved aqueous sample is 

accurately transferred to a clean 50-mL plastic disposable digestion tube containing 

a mixture of nitric and hydrochloric acids. The aliquot is heated to 95 °C (± 2 °C),

evaporated to approximately 25 mL, covered with a ribbed plastic watch glass and

subjected to total recoverable solubilization with gentle refluxing for 30 minutes. 

The sample is allowed to cool and diluted to 25 mL with reagent water to effect a 

2X preconcentration. The sample is capped, mixed and now ready for analysis (The

time required to complete the sample preparation step is approximately 2.5 hours). 

2.2 The analytical determinative step described in this method involves multi-elemental 

determinations by AVICP-AES using sequential or simultaneous instruments. The 

instruments measure characteristic atomic-line emission spectra by optical 

spectrometry. Standard and sample solutions are nebulized by pneumatic 

nebulization and the resulting aerosol is transported by argon carrier-gas to the

plasma torch. Element specific emission spectra are produced by a radio-frequency

inductively coupled plasma. The spectra are dispersed by a grating spectrometer, 

and the intensities of the line spectra are monitored at specific wavelengths by a

photosensitive device. Photo currents from the photosensitive device are processed

and controlled by a computer system. A background correction technique is 

200.5-4
required to compensate for variable background contribution to the determination of 

the analytes. Background should be measured adjacent to the analyte wavelength

during analysis. Possible interferences that can occur must be considered and 

addressed appropriately as discussed in Section 4. 

3.0 DEFINITIONS 

3.1 CALIBRATION BLANK - A volume of reagent water acidified with the same acid 

matrix reagents as in the calibration standards. The calibration blank is a zero 

standard and is used to calibrate the AVICP instrument (Sects. 7.9.1). 

3.2 CALIBRATION STANDARD (CAL) - A solution prepared from the dilution of 

stock standard solutions. The CAL solutions contain the acid matrix reagents and

are used to calibrate the instrument response with respect to analyte concentration

(Sect. 7.8.1). 

3.3 DISSOLVED ANALYTE - The concentration of analyte in an aqueous sample that 

will pass through a 0.45-:m membrane filter assembly prior to sample acidification. 

3.4 FIELD REAGENT BLANK (FRB) - An aliquot of reagent water that is placed in a 

sample container in the laboratory and treated as a sample in all respects, including

shipment to the sampling site, exposure to the sampling site conditions, storage, acid

preservation, and all analytical procedures. The FRB is used to determine if method 

analytes or interferences are present in the field environment (Sect. 8.2). 

3.5 INSTRUMENT DETECTION LIMIT (IDL) - The concentration equivalent to the

analyte signal which is equal to three times the standard deviation of a series of ten 

replicate measurements of the calibration blank signal at the same wavelength. 

3.6 INSTRUMENT PERFORMANCE CHECK (IPC) SOLUTION - A solution of 

method analytes in the acid matrix reagents used to evaluate the performance of the 

instrument system with respect to a defined set of method criteria (Sects. 7.10.3 &

9.3.4). 

3.7 LABORATORY DUPLICATES (LD1 and LD2) - Two aliquots of the same sample 

taken in the laboratory and analyzed separately with identical procedures. Analyses

of LD1 and LD2 indicates precision associated with laboratory procedures, but not

with sample collection, preservation, or storage procedures. 

3.8 LABORATORY FORTIFIED BLANK (LFB) - An aliquot of LRB to which known

quantities of the method analytes are added in the laboratory. The LFB is analyzed

exactly like a sample, and its purpose is to determine whether the methodology is in

control and whether the laboratory is capable of making accurate and precise 

measurements (Sects. 7.9.3 & 9.3.2). 

3.9 LABORATORY FORTIFIED SAMPLE MATRIX (LFM) - An aliquot of a

drinking water or drinking water supply sample to which known quantities of the 

method analytes are added in the laboratory. The LFM is analyzed exactly like a 

200.5-5
sample, and its purpose is to determine whether the sample matrix contributes bias 

to the analytical results. The background concentrations of the analytes in the 

sample matrix must be determined in a separate aliquot and the measured values in 

the LFM corrected for background concentrations (Sects. 1.6, 1.7 & 9.4). 

3.10 LABORATORY REAGENT BLANK (LRB) - An aliquot of reagent water that is

treated exactly as a sample including exposure to all labware, equipment, and 

reagents, that are used with other samples. The LRB is used to determine if method 

analytes or other interferences are present in the laboratory environment, reagents,

or apparatus (Sects. 7.9.2 & 9.3.1). 

3.11 LINEAR DYNAMIC RANGE (LDR) - The concentration range over which the

instrument response to an analyte is linear (Sect. 9.2.2). 

3.12 MAXIMUM CONTAMINANT LEVEL (MCL) - The maximum permissible level 

of a contaminant in water which is delivered to any user of a public water system. 

3.13 METHOD DETECTION LIMIT (MDL) - The minimum concentration of an analyte

that can be identified, measured, and reported with 99% confidence that the analyte

concentration is greater than zero (Sects. 1.11, 1.12, 9.2.5 and Table 4). 

3.14 PLASMA SOLUTION - A solution used to determine the nebulizer argon flow rate

or gas pressure that will produce the optimum net-signal-to-noise (S-B/B) needed

for the most requiring analyte included in the analytical scheme (Sects. 7.11 &

10.2). 

3.15 QUALITY CONTROL SAMPLE (QCS) - A solution of method analytes of known

concentrations which is used to fortify an aliquot of LRB or sample matrix. The 

QCS is obtained from a source external to the laboratory and different from the 

source of calibration standards. It is used to check either laboratory or instrument 

performance (Sects. 7.10.4 & 9.2.4). 

3.16 SPECTRAL INTERFERENCE CHECK (SIC) SOLUTION - A solution of selected 

method analytes of higher concentrations which is used to evaluate the procedural

routine for correcting known interelement spectral interferences with respect to a

defined set of method criteria (Sects. 4.1 & 9.3.5). 

3.17 STANDARD ADDITION - The addition of a known amount of analyte to the 

sample in order to determine the relative response of the detector to an analyte

within the sample matrix. The relative response is then used to assess either an

operative matrix effect or the sample analyte concentration (Sects. 1.6 & 11.3). 

3.18 STOCK STANDARD SOLUTION - A concentrated solution containing one or 

more method analytes prepared in the laboratory using assayed reference materials 

or purchased from a reputable commercial source (Sect. 7.7). 

3.19 TOTAL RECOVERABLE ANALYTE - For this method, the concentration of 

analyte determined by the analysis of an unfiltered acid preserved drinking water 

200.5-6
sample following digestion by refluxing with hot dilute mineral acid(s) as specified

in the method (Sects. 1.5 & 11.1). Data are reported as a “total” element 

determination - the combined concentrations of the dissolved and suspended

fractions of the sample. 

4.0 INTERFERENCES 

4.1 Spectral interferences are caused by background emission from continuous or 

recombination phenomena, stray light from the line emission of high concentration

elements, overlap of a spectral line from another element, or unresolved overlap of 

molecular band spectra. Except for interference from background emission and 

possible stray light, which can usually be compensated for by subtracting the

background emission adjacent to the analyte wavelength peak, spectral interferences

associated with the analysis of drinking water are minimal. However, the absence of 

interelement spectral interference should be verified. Criteria for determining an

interelement spectral interference is an apparent positive or negative

concentration on the analyte that is outside the 3-sigma control limits of the

calibration blank for the analyte. When an instrument equipped with a

conventional diffraction grating that provides 0.016 nm first order resolution is used 

with the wavelengths in the noted spectral order and background correction

locations given in Table 1, no detectable concomitant interelement spectral

interferences occurs between the trace element analytes listed in this method at 

concentrations # 20 mg/L. Since concentrations of trace elements in drinking water

and drinking water supplies are far below the level of 20 mg/L, an interelement 

correction routine for trace analytes would be unnecessary for an instrument so 

configured. On the other hand, the concentration of the water matrix elements can 

be in excess of 100 mg/L. Fortunately, the matrix elements are not spectrally rich

and have few prominent lines to cause interelement spectral interference. Using this 

method and analyzing single element solutions of 300 mg/L Ca, 200 mg/L Mg, 200 

mg/L Na, and 100 mg/L Si, no spectral enhancement of other method analytes were

observed, thus not requiring interelement corrections. However, there are three 

concerns worth noting: (1) yttrium, a commonly used internal standard, proved an

interference in the spectral region recommended for background correction on the

listed Ag wavelength (328.068 nm), (2) a similar situation occurs from molybdenum

on the spectral region recommended for background correction on the V wavelength

(292.402 nm), and (3) the listed Fe wavelength (271.441 nm) experiences an

apparent concentration increase of approximately 8% from cobalt (271.442 nm)

when the two analytes are present in equal concentration. Therefore, a quality

control check sample containing both iron and cobalt or both vanadium and 

molybdenum should not be used to confirm the calibration standards when the Fe 

271.441 nm and V 292.402 nm wavelengths are utilized. 

Note: If wavelengths, noted spectral order, and background correction locations

different from those listed in Table 1 are used with this method, and/or the optical

resolution of the instrument utilized does not provide 0.016 nm first order resolution 

or better, the absence of interelement spectral interference must be confirmed by 

completing spectral scans over the wavelength area and background correction

locations to be utilized. The spectral scans should be completed using single 

200.5-7
element solutions of both trace and water matrix elements of concentrations noted 

above that will verify nonexistent apparent analyte concentrations. If an 

interelement spectral interference is detected, a correction routine that is operative

during analysis must be used with daily verification using SIC solutions, to

demonstrate that the routine meets the above criteria. 

4.2 Physical interferences are effects associated with the sample nebulization and 

transport processes. Changes in viscosity and surface tension can cause significant

inaccuracies, especially in samples containing high dissolved solids or high acid

concentrations. Physical interferences of the types described above have not been

evident in the analysis of most drinking waters. However, the use of a peristaltic 

pump to regulate solution uptake rate and the use of mass flow controllers that 

provide better control of the argon flow rates, especially for the nebulizer, improve

instrument stability and precision. 

4.3 Chemical interferences include molecular-compound formation, ionization effects, 

and solute-vaporization effects. In general, chemical interferences are highly

dependent on matrix type and the specific element. In radial ICP-AES, one way of

controlling these effects is careful selection of the observation height in the plasma. 

However, for increased sensitivity, the total emission of the plasma is observed in 

AVICP-AES, thus eliminating this useful option. To counteract ionization and 

matrix interferences in AVICP-AES, some laboratories routinely use an ionization

buffer along with an internal standard added to both standards and samples alike in 

the sample train using a peristaltic pump and mixing tee. Use of an ionization buffer 

is permitted with this method provided the addition does not cause an interelement 

spectral interference with a method analyte. However, in drinking water analyses

the use of an internal standard with pneumatic nebulization is discouraged because it

is not necessary and adds additional variance to the determination. The above stated 

chemical interferences have not been observed using this method for drinking water

analyses when the operating conditions and preparations procedures are followed as

written. 

4.4 Memory interferences result when analytes in a previous sample contribute to the 

signals measured in a new sample. Memory effects can result from sample 

deposition on the uptake tubing to the nebulizer and from the buildup of sample 

material in the plasma torch and spray chamber. The site where these effects occur 

is dependent on the element and can be minimized by flushing the system with a 

rinse blank between samples (Sect. 7.9.4). The rinse times necessary for a particular

element should be estimated prior to analysis. For the water matrix elements this 

may be achieved by aspirating a single element standard solution corresponding to

their LDRs (Sect. 3.11), while for the trace contaminants single element solutions 

containing 10 mg/L are sufficient. The aspiration time should be the same as a 

normal sample analysis period, followed by analysis of the rinse blank at designated

intervals. The length of time required to reduce analyte signal to within a factor of

10 times the calibration blank should be noted. Until the required rinse time is 

established, this method requires a rinse period using the rinse blank of at least

30 sec between samples and standards. If a memory interference is suspected, the 

sample should be re-analyzed after a long rinse period. 

200.5-8
5.0 SAFETY 

5.1 The toxicity or carcinogenicity of each reagent used in this method have not been 

fully established. Each chemical should be regarded as a potential health hazard and

exposure to these compounds should be as low as reasonably achievable. Each 

laboratory is responsible for maintaining a current awareness file of OSHA

regulations regarding the safe handling of the chemicals specified in this method (3-5). 

A reference file of material data handling sheets should also be made available to all 

personnel involved in the chemical analysis. Specifically, concentrated nitric and

hydrochloric acids are moderately toxic and extremely irritating to skin and mucus 

membranes. Use these reagents in a fume hood whenever possible and if eye or skin

contact occurs, flush with large volumes of water. Always wear safety glasses or a

shield for eye protection, protective clothing and observe proper mixing when

working with these reagents. 

5.2 Acidification of samples should be done in a fume hood. 

5.3 The inductively coupled plasma should only be viewed with proper eye protection

from the ultraviolet emissions. 

5.4 It is the responsibility of the user of this method to comply with relevant disposal

and waste regulations. For guidance see Sections 14.0 and 15.0. 

6.0 EQUIPMENT AND SUPPLIES 

6.1 Axially viewed inductively coupled plasma emission spectrometer: 

6.1.1 Computer-controlled emission spectrometer with background-correction

capability. The spectrometer must be capable of meeting and complying

with the requirements described and referenced in Section 2.2. 

6.1.2 Radio-frequency generator compliant with FCC regulations. 

6.1.3 Argon gas supply - High purity grade (99.99%). When analyses are

conducted frequently, liquid argon is more economical and requires less

frequent replacement of tanks than compressed argon in conventional

cylinders. 

6.1.4 A variable speed peristaltic pump is required to deliver both standard and 

sample solutions to the nebulizer. 

6.1.5 (optional) A mass flow controller to regulate or monitor the argon flow

rate of the aerosol transport gas is highly recommended. Use of a mass 

flow controller will provide more exacting control of reproducible plasma 

conditions. 

6.2 An analytical balance with capability to measure to 0.1 mg, for use in preparing 

200.5-9
standards and for weighing samples as may be required. 

6.3 A temperature adjustable hot plate for preparing stock standard solutions. 

6.4 A temperature adjustable block digester capable of maintaining a temperature of 

95 o

C for use with 50-mL plastic disposable digestion tube. 

6.5 A gravity convection drying oven with thermostatic control capable of maintaining

180 o

C ± 5 oC. 

6.6 Air displacement pipetters capable of delivering volumes ranging from 50 :L to 

10.0 mL with an assortment of high quality disposable pipet tips. 

6.7 Labware - For determination of trace levels of elements, contamination and loss are 

of prime consideration. Potential contamination sources include improperly cleaned

laboratory apparatus and general contamination within the laboratory environment 

from dust, etc. A clean laboratory work area designated for trace element sample 

handling should be used. Sample containers can introduce positive and negative

errors in the determination of trace elements by (1) contributing contaminants 

through surface desorption or leaching, and (2) depleting element concentrations 

through adsorption processes. All reusable labware (polyethylene,

polymethylpentene, PTFE, FEP, etc.) and plastic disposable digestion tubes, caps,

and watch glasses should be sufficiently clean for the task objectives. Several 

cleaning procedures can provide clean labware. The procedure recommended for 

reusable labware includes washing with a detergent solution, rinsing with tap water,

and soaking for 4 h or more in a mixture of 5% (v/v) HNO3 and 5% (v/v) HCl,

rinsing with reagent water and storing clean. (If digested LRBs indicate random 

contamination, the plastic disposable digestion tubes, caps, and watch glasses should

be cleaned with 2% (v/v) HNO3 and rinsed with reagent water prior to use.)

Chromic acid cleaning solutions must be avoided because chromium is an analyte. 

6.7.1 Plastic volumetric labware - PMP (polymethylpentene) or equivalent 

metal free plastic volumetric flasks (50-mL to 500-mL capacities),

graduated cylinders (50-mL), and disposable metal-free plastic digestion

tubes with caps and watch glass covers. 

6.7.2 (optional) PTFE Griffin beakers, 250-mL with PTFE covers for preparing

stock standards and reagents. 

6.7.3 Narrow-mouth storage bottles, FEP (fluorinated ethylene propylene) and

LDPE (low density polyethylene) with screw closure, 60-mL to 500-mL 

capacities. 

6.7.4 One-piece stem FEP wash bottle with screw closure, 125-mL capacity. 

7.0 REAGENTS AND STANDARDS 

7.1 Reagents may contain elemental impurities which might affect analytical data. Only 

200.5-10
high-purity reagents that conform to the American Chemical Society specifications 

must be used whenever possible. If the purity of a reagent is in question, analyze for 

contamination. All acids used for this method should be of ultra high-purity grade

or equivalent. Trace metal grade acid may also be used if it can be verified by

analysis to be free of contamination. Suitable acids are available from a number of 

manufacturers. Redistilled acids prepared by sub-boiling distillation are acceptable. 

7.2 Hydrochloric acid, concentrated (sp.gr. 1.19) - HCl. 

7.2.1 Hydrochloric acid (1+1) - Add 250 mL concentrated HCl to 200 mL 

reagent water and dilute to 500 mL. 

7.2.2 Hydrochloric acid (1+20) - Add 10 mL concentrated HCl to 200 mL 

reagent water. 

7.3 Nitric acid, concentrated (sp.gr. 1.41) - HNO3. 

7.3.1 Nitric acid (1+1) - Add 250 mL concentrated HNO3 to 200 mL reagent

water and dilute to 500 mL. 

7.3.2 Nitric acid (1+2) - Add 100 mL concentrated HNO3 to 200 mL reagent water. 

7.3.3 Nitric acid (1+5) - Add 50 mL concentrated HNO3 to 250 mL reagent water. 

7.3.4 Nitric acid (1+9) - Add 10 mL concentrated HNO3 to 90 mL reagent water. 

7.4 Reagent water. All references to reagent water in this method refer to ASTM Type I

grade water(6). 

7.5 Ammonium hydroxide, concentrated (sp. gr. 0.902). 

7.6 Tartaric acid, ACS reagent grade. 

7.7 Standard Stock Solutions - Stock standards may be purchased or prepared from

ultra-high purity grade chemicals (99.99 to 99.999% pure). All compounds must be 

dried for 1 h at 105 oC, unless otherwise specified. It is recommended that stock 

solutions be stored in acid-cleaned, never-used LDPE bottles for storage. Replace

stock standards when succeeding dilutions for preparation of calibration standards

can not be verified (see Sect. 9.2.4). 

CAUTION: Many of these chemicals are extremely toxic if inhaled or

swallowed (Sect. 5.1). Wash hands thoroughly after handling. 

Typical stock solution preparation procedures follow for 500-mL quantities, but for

the purpose of pollution prevention, the analyst is encouraged to prepare smaller 

quantities when possible. Concentrations are calculated based upon the weight of

the pure element or upon the weight of the compound multiplied by the fraction of

the analyte in the compound. 

200.5-11
7.7.1 Aluminum solution, stock, 1 mL = 1000 :g Al: Dissolve 0.500 g of

aluminum metal, weighed accurately to at least three significant figures, in

an acid mixture of 4.0 mL of (1+1) HCl and 1.0 mL of concentrated HN03 

in a beaker. Warm beaker slowly to effect solution. When dissolution is 

complete, transfer solution quantitatively to a 500-mL PMP flask, add an 

additional 5.0 mL of (1+1) HCl and dilute to volume with reagent water. 

7.7.2 Antimony solution, stock, 1 mL = 1000 :g Sb: Dissolve 0.500 g of

antimony powder, weighed accurately to at least three significant figures,

in 10.0 mL (1+1) HNO3 and 5.0 mL concentrated HCl in a beaker. Add 

50 mL reagent water and 0.75 g tartaric acid. Warm solution slightly to

effect complete dissolution. Cool solution and add reagent water to

volume in a 500-mL PMP volumetric flask. 

7.7.3 Arsenic solution, stock, 1 mL = 1000 :g As: Dissolve 0.660 g of As2O3 

(As fraction = 0.7574), weighed accurately to at least three significant

figures, in 50 mL of reagent water containing 5.0 mL concentrated 

NH4OH in a beaker. Warm the solution gently to effect dissolution.

Acidify the solution with 10.0 mL concentrated HNO3 and dilute to 

volume in a 500-mL PMP volumetric flask with reagent water. 

7.7.4 Barium solution, stock, 1 mL = 1000 :g Ba: Dissolve 0.719 g BaCO3 

(Ba fraction = 0.6960), weighed accurately to at least three significant

figures, in a beaker containing 75 mL (1+2) HNO3 with heating and

stirring to degas and dissolve compound. Let solution cool and dilute with 

reagent water in 500-mL PMP volumetric flask. 

7.7.5 Beryllium solution, stock, 1 mL = 1000 :g Be: DO NOT DRY. Dissolve 

9.823 g BeSO4•4H2O (Be fraction = 0.0509), weighed accurately to at

least four significant figures, in reagent water, add 5.0 mL concentrated 

HNO3, and dilute to volume in a 500-mL PMP volumetric flask with 

reagent water. 

7.7.6 Boron solution, stock, 1 mL = 1000 :g B: DO NOT DRY. Dissolve 

2.859 g anhydrous H3BO3 (B fraction = 0.1749), weighed accurately to at

least four significant figures, in reagent water and dilute in a 500-mL PMP 

volumetric flask with reagent water. 

7.7.7 Cadmium solution, stock, 1 mL = 1000 :g Cd: Dissolve 0.500 g Cd 

metal, acid cleaned with (1+9) HNO3, weighed accurately to at least three

significant figures, in 25 mL (1+1) HNO3 in a beaker with heating to

effect dissolution. Let solution cool and dilute with reagent water in a

500-mL PMP volumetric flask. 

7.7.8 Calcium solution, stock, 1 mL = 1000 :g Ca: Suspend 1.249 g CaCO3 

(Ca fraction = 0.4005), dried at 180 °C for 1 h before weighing, weighed

accurately to at least four significant figures, in reagent water and dissolve 

200.5-12
cautiously with a minimum amount of (1+1) HNO3. Add 5.0 mL 

concentrated HNO3 and dilute in a 500-mL PMP volumetric flask with 

reagent water. 

7.7.9 Chromium solution, stock, 1 mL = 1000 :g Cr: Dissolve 0.962 g CrO3 

(Cr fraction = 0.5200), weighed accurately to at least three significant

figures, in 60 mL (1+5) HNO3. When dissolution is complete, dilute in a 

500-mL PMP volumetric flask with reagent water. 

7.7.10 Copper solution, stock, 1 mL = 1000 :g Cu: Dissolve 0.500 g Cu metal, 

acid cleaned with (1+9) HNO3, weighed accurately to at least three

significant figures, in 25 mL (1+1) HNO3 in a beaker with heating to

effect dissolution. Let solution cool and dilute in a 500-mL PMP 

volumetric flask with reagent water. 

7.7.11 Iron solution, stock, 1 mL = 1000 :g Fe: Dissolve 0.500 g Fe metal, acid 

cleaned with (1+1) HCl, weighed accurately to three significant figures, in

50 mL (1+1) HCl in a beaker with heating to effect dissolution. Let 

solution cool and dilute in a 500-mL PMP volumetric flask with reagent 

water. 

7.7.12 Lead solution, stock, 1 mL = 1000 :g Pb: Dissolve 0.799 g Pb(NO3)2 

(Pb fraction = 0.6256), weighed accurately to at least three significant

figures, in a minimum amount of (1+1) HNO3. Add 10.0 mL (1+1) HNO3 

and dilute in a 500-mL PMP volumetric flask with reagent water. 

7.7.13 Magnesium solution, stock, 1 mL = 1000 :g Mg: Dissolve 0.500 g of

cleanly polished Mg ribbon, accurately weighed to at least three

significant figures, in slowly added 2.5 mL (1+1) HCl (CAUTION: 

reaction is vigorous). Add 10.0 mL (1+1) HNO3 and dilute in a 500-mL 

PMP volumetric flask with reagent water. 

7.7.14 Manganese solution, stock, 1 mL = 1000 :g Mn: Dissolve 0.500 g of 

manganese metal, weighed accurately to at least three significant figures,

in 25 mL (1+1) HNO3 and dilute to volume in a 500-mL PMP volumetric 

flask with reagent water. 

7.7.15 Nickel solution, stock, 1 mL = 1000 :g Ni: Dissolve 0.500 g of nickel 

metal, weighed accurately to at least three significant figures, in 10.0 mL 

hot concentrated HNO3, cool, and dilute in a 500-mL PMP volumetric 

flask with reagent water. 

7.7.16 Selenium solution, stock, 1 mL = 1000 :g Se: Dissolve 0.703 g SeO2 

(Se fraction = 0.7116), weighed accurately to at least three significant

figures, in 100 mL reagent water and dilute to volume in a 500-mL PMP 

volumetric flask with reagent water. 

7.7.17 Silica solution, stock, 1 mL = 1000 :g SiO2: DO NOT DRY. Dissolve 

200.5-13
1.482 g (NH4)2SiF6, weighed accurately to at least four significant figures,

in 100 mL (1+20) HCl in a beaker with heating at 85 °C to effect

dissolution. Let solution cool and dilute in a 500-mL PMP volumetric 

flask with reagent water. 

7.7.18 Silver solution, stock, 1 mL = 1000 :g Ag: Dissolve 0.500 g Ag metal, 

weighed accurately to at least three significant figures, in 50 mL (1+1)

HNO3 in a beaker with heating to effect dissolution. Let solution cool and 

dilute in a 500-mL PMP volumetric flask with reagent water. 

7.7.19 Sodium solution, stock, 1 mL = 1000 :g Na: Dissolve 1.271 g NaCl

(Na fraction = 0.3934), weighed accurately to at least four significant

figures, in reagent water. Add 5.0 mL concentrated HNO3 and dilute to 

volume in a 500-mL PMP volumetric flask with reagent water. 

7.7.20 Tin solution, stock, 1 mL = 1000 :g Sn: Dissolve 0.500 g Sn shot,

weighed accurately to at least three significant figures, in an acid mixture 

of 5.0 mL concentrated HCl and 1.0 mL (1+1) HNO3 in a beaker with 

heating to effect dissolution. Let solution cool, add 100 mL concentrated 

HCl, and dilute to volume in a 500-mL PMP volumetric flask with reagent 

water. 

7.7.21 Vanadium solution, stock, 1 mL = 1000 :g V: Dissolve 0.500 g V metal, 

acid cleaned with (1+9) HNO3, weighed accurately to at least three

significant figures, in 25 mL (1+1) HNO3 in a beaker with heating to

effect dissolution. Let solution cool and dilute in a 500-mL PMP 

volumetric flask with reagent water. 

7.7.22 Zinc solution, stock, 1 mL = 1000 :g Zn: Dissolve 0.500 g Zn metal, acid 

cleaned with (1+9) HNO3, weighed accurately to at least three significant

figures, in 25 mL (1+1) HNO3 in a beaker with heating to effect

dissolution. Let solution cool and dilute in a 500-mL PMP volumetric 

flask with reagent water. 

7.8 Calibration Standard Solutions. 

7.8.1 Mixed Calibration Standard Solutions - For total recoverable analyses 

prepare mixed calibration standard solutions by combining appropriate

volumes of the stock solutions in 500-mL PMP volumetric flasks 

containing 20 mL (1+1) HNO3 and 10 mL (1+1) HCl and dilute to volume 

with reagent water. Prior to preparing the mixed standards, each stock 

solution should be analyzed separately to determine possible spectral

interferences or the presence of impurities. Care should be taken when 

preparing the mixed standards to ensure that the elements are compatible 

and stable together. To minimize the opportunity for contamination by the

containers, it is recommended to transfer the mixed-standard solutions to 

acid-cleaned, never-used FEP fluorocarbon (FEP) bottles for storage.

Fresh mixed standards should be prepared, as needed, with the realization 

200.5-14
that concentrations can change on aging. Calibration standards not 

prepared from primary standards must be initially verified using a certified 

reference solution. Recommended wavelengths and calibration

concentrations are listed in Table 1. Typical calibration standard 

combinations are given in Table 2. 

7.8.2 Sodium Multi-point Calibration Standards - To determine elevated 

concentrations of Na in drinking water and drinking water supplies using

the recommended wavelength, Na is determined using a multi-point

analytical calibration usable to 160 mg/L. Prepare in a mixture of 2% 

HNO3 (v/v) and 1% HCl (v/v) a calibration blank and six calibration

standards at concentrations of 5, 10, 20, 40, 80, and 160 mg/L,

respectively. To create the multi-point calibration, curve-fit the response

of the blank and standards and store as a computer file. This calibration is 

standardized before each period of analysis using the calibration blank and

the mixed calibration standard solution containing 20 mg/L Na

(Sect. 7.8.1). A new multi-point calibration should be prepared whenever

there is a change in analytical performance caused by either a change in

instrument hardware or operating conditions. (Of the 990 ground water 

samples analyzed in the National Inorganic Radionuclide Survey, Na was

reported below 90 mg/L in 84% of the samples.) 

7.9 Blanks - Four types of blanks are required for this method. The calibration blank is 

used in establishing the analytical curve, the laboratory reagent blank is used to

assess possible contamination from the laboratory procedure, the laboratory fortified

blank is used to assess routine laboratory performance and a rinse blank is used to 

flush the uptake system to reduce memory interferences. 

7.9.1 The calibration blank is prepared by diluting 20 mL (1+1) HNO3 and 10 

mL (1+1) HCl in a 500-mL PMP volumetric flask to volume with reagent 

water. Store the prepared blank solution to an acid-cleaned, never-used

500-mL FEP bottle. This bottle should be dedicated for reuse and storage

of this solution. 

7.9.2 The laboratory reagent blank (LRB) is prepared by carrying 50 mL of 

reagent water through the entire analytical procedure. The LRB must 

contain all the reagents in the same volumes as used in processing the 

samples. 

7.9.3 The laboratory fortified blank (LFB) is prepared in the same manner as the 

LRB, and fortified by adding 1.0 mL of the fortifying solution (7.10.1) to

50 mL of LRB. The LFB must be carried through the entire analytical

procedure. The analyte concentrations fortified in the LFB are as follows:

4 μg/L Be; 5 μg/L Cd; 6 μg/L Sb; 10 μg/L As; 15 μg/L Pb; 50 μg/L Ag,

Mn, Se, Sn and V; 100 μg/L B, Cr and Ni; 200 μg/L Al; 300 μg/L Fe;

1000 μg/L Ba, Cu and Zn. 

200.5-15
7.9.4 The rinse blank is prepared by acidifying reagent water in an acid-cleaned

LDPE bottle to concentrations of 2% (v/v) HNO3 + 2% (v/v) HCl. 

7.10 Quality Control Solutions. 

7.10.1 Fortifying solution - The fortifying solution is used to prepare the

laboratory fortified blank (LFB) and laboratory fortified matrix (LFM)

solutions. The fortifying solution should be prepared in a 100-mL PMP 

volumetric flask, containing a mixture of 4 mL (1+1) HNO3 and 2 mL 

(1+1) HCl, by combining the following listed aliquot volumes of each 

stock standard and the low-level stock fortifying solution (7.10.2) and

diluting to volume with reagent water: 5 mL Ba, Cu & Zn and the lowlevel stock fortifying solution; 1.5 mL Fe; 1.0 mL Al; 0.5 mL B, Cr & Ni; 

and 0.25 mL Ag, Mn, Se, Sn & V. Store in a new, acid-cleaned LDPE

bottle. The analyte concentrations in the fortifying solution are as follows: 

50 mg/L Ba, Cu & Zn; 15 mg/L Fe; 10 mg/L Al ; 5.0 mg/L B, Cr & Ni;

2.5 mg/L Ag, Mn, Se, Sn & V; 0.75 mg/L Pb; 0.50 mg/L As; 0.30 

mg/L Sb; 0.25 mg/L Cd; and 0.20 mg/L Be. 

7.10.2 Low-level stock fortifying solution - The low-level stock fortifying

solution is used to prepare the fortifying solution described in Section

7.10.1. The low-level stock fortifying solution is prepared in a 50-mL 

PMP volumetric flask, containing a mixture of 2 mL (1+1) HNO3 and 

1 mL (1+1) HCl, by combining the following listed aliquot volumes of 

each stock standard and diluting to volume with reagent water: 750 μL Pb

(15 mg/L); 500 μL As (10 mg/L); 300 μL Sb (6 mg/L); 250 μL Cd

(5 mg/L); and 200 μL Be (4 mg/L). (The concentration in parenthesis is

that of the analyte in the low-level stock.) Store in a new, acid-cleaned 

LDPE bottle dedicated for reuse and repeated storage of this solution. 

7.10.3 Instrument Performance Check (IPC) Solution - The IPC solution is used

to periodically verify instrument performance during analysis. It should 

be prepared by combining method analytes at appropriate concentrations

in the same acid mixture (2% HNO3 + 1% HCl) as the calibration

standards. Silver should be limited to < 100 μg/L; while Al and Fe should

be made to a concentration of 2 mg/L; Ca, Mg, and SiO2 made to 5 mg/L;

and Na to a concentration of 10 mg/L. For all other analytes, a

concentration of 200 μg/L is recommended. The IPC should be prepared

in a PMP (metal-free plastic) volumetric flask to avoid B and SiO2 

contamination. Store the IPC solution in a new, acid-cleaned FEP bottle 

dedicated for reuse and repeated storage of this solution. 

NOTE: If the instrument readout system incorporates the use of a dilution

factor (0.5) to report original sample concentration prior to processing,

and the IPC solution is analyzed in the same manner as the samples, the 

reported IPC concentrations will be half the concentrations listed above. 

7.10.4 Quality Control Sample (QCS) - Analysis of a QCS is required for initial 

200.5-16
and periodic verification of calibration standards or stock standard

solutions in order to verify instrument performance. The QCS must be 

obtained from outside source different from the standard stock solutions 

and prepared in a PMP volumetric flask using the same acid mixture as the 

calibration standards. The concentration of the analytes in the QCS

solution should be sufficient to meet the data quality objectives given in

Section 9.2.4. The concentrations may range from 200 μg/L for sensitive

analytes such as Be and Cd to > 2.0 mg/L for Al, Ca, Fe, Mg, Na, and

SiO2. However, the concentration of Ag should be limited to 0.1 mg/L or

less to ensure complete solubility and stability. The QCS solution should 

be stored in a new, acid-cleaned LDPE bottle and analyzed as needed to 

meet data-quality needs. A fresh solution should be prepared quarterly or 

more frequently as needed. 

7.11 Plasma Solution - The plasma solution is used for determining the nebulizer argon

flow rate or gas pressure that will produce the optimum net-signal-to-background

noise (S-B/B) ratio needed for the most requiring analytes included in the method 

without degrading the performance of the other analytes. The two analytes that

present the greatest challenge are Sb and As because of the low MCLs and limited 

analytical sensitivity. The combined 1 mg/L solution is prepared by adding 100 μL

of the Sb stock standard (7.7.2) and a 100 μL of the As stock standard (7.7.3) to a 

mixture of 4 mL (1+1) HNO3 and 2 mL (1+1) HCL in a 100-mL PMP volumetric 

and diluting to volume with reagent water. Store the solution in a new, acid-cleaned 

LPDE bottle for repeated use as necessary. 

8.0 SAMPLE COLLECTION, PRESERVATION, AND STORAGE 

8.1 For the determination of trace and water matrix elements in drinking water and

drinking water supplies, samples are not filtered, but acidified with (1+1) nitric acid

to a pH < 2 (3 mL of [1+1] acid per liter of sample should be sufficient).

Preservation may be done at the time of collection; however, to avoid the hazards of 

strong acids in the field, transport restrictions and possible contamination, it is 

recommended that the samples be returned to the laboratory within two weeks of

collection and acid preserved upon receipt in the laboratory. Following

acidification, the sample should be mixed, held for sixteen hours, and then verified 

to be pH < 2 just prior to withdrawing an aliquot for sample processing. If for some 

reason, such as high alkalinity, the sample pH is verified to be > 2, more acid must 

be added and the sample held for sixteen hours until verified to be pH < 2. If

properly preserved, the sample can be held up to 6 months. 

8.2 If required by the data user, a field reagent blank (Sect. 3.4) should be prepared and

analyzed in the same manner as a collected sample. Use the same type of container

and acid as used in sample collection. 

9.0 QUALITY CONTROL 

9.1 Each laboratory using this method is required to operate a formal quality control

(QC) program. The minimum requirements of this program consists of an initial 

200.5-17
demonstration of laboratory capability, and the periodic analysis of laboratory

reagent blanks, fortified blanks and other laboratory solutions as a continuing check

on performance. The laboratory is required to maintain performance records that 

define the quality of the data thus generated. 

9.2 Initial Demonstration of Performance (mandatory). 

9.2.1 The initial demonstration of performance is used to characterize instrument 

performance (determination of linear dynamic ranges and analysis of

quality control samples) and laboratory performance (determination of 

method detection limits) prior to analyses conducted by this method. 

9.2.2 Linear dynamic range (LDR) - The upper limit of the LDR must be 

established for each wavelength used for the analysis of the drinking water 

matrix analytes: Ca, Mg and silica. It must be determined from a linear 

calibration prepared using the established instrument operating conditions.

The LDR should be determined by analyzing succeedingly higher standard

concentrations of the analyte until the observed analyte concentration is no 

more than 10% below the stated concentration of the standard. Determined 

LDRs must be documented and kept on file. The LDR which may be used

for the analysis of samples should be judged by the analyst from the 

resulting data. Determined sample analyte concentrations that are greater

than 90% of the determined upper LDR limit must be diluted and 

reanalyzed. The LDRs should be verified as required for certification or

whenever, in the judgment of the analyst, a change in analytical

performance caused by either a change in instrument hardware or operating

conditions would dictate they be redetermined. 

9.2.3 Non-linear dynamic range - The upper limit of the non-linear calibration 

used for the determination of Na is the highest standard used to describe the

calibration curve. The non-linear calibration must be established using the 

same instrument operating conditions used for analysis. Determined 

sample concentrations that are > 10% above the upper limit for Na must be 

diluted and reanalyzed. The upper limit should be verified as required for

certification or whenever, in the judgment of the analyst, a change in

analytical performance caused by either a change in instrument hardware or 

operating conditions would dictate they be redetermined. 

9.2.4 Quality control sample (QCS) - When beginning the use of this method, on 

a quarterly basis, after the preparation of stock or calibration standard

solutions, or as required to meet data-quality needs, verify the calibration 

standards and acceptable instrument performance with the preparation and

analysis of a QCS (Sect. 7.10.4.) To verify the calibration standards, the

determined mean concentrations from 3 analyses of the QCS must be 

within ± 5% of the stated values. If the calibration standard can not be 

verified, performance of the determinative step of the method is 

unacceptable. The source of the problem must be identified and corrected 

before either proceeding on with the initial determination of method 

200.5-18
detection limits or continuing with on-going analyses. 

9.2.5 Method detection limit (MDL) - MDLs must be established for all 

wavelengths utilized for trace element determinations in total recoverable 

digestates. MDLs are determined using reagent water (blank) fortified to a

concentration ranging from the instrument detection limit (IDL) to

approximately two times the IDL(7) (see Table 4 for typical levels). To 

determine MDL values, take seven replicate aliquots of the fortified reagent

water and process through the entire total recoverable analytical procedure.

Perform all calculations defined in the method and report the concentration

values in the appropriate units. Calculate the MDL as follows: 

MDL = (t) x (S) 

where: t = students' t value for a 99% confidence level and 

a standard deviation estimate with n-1 degrees

of freedom (t = 3.14 for seven replicates). 

S = standard deviation of the replicate analyses. 

Note: If the relative standard deviation (RSD) from the analyses of the

seven aliquots is < 10% and neither random nor reagent contamination is 

operative, the concentration used to determine the analyte MDL may have

been inappropriately high for the determination. If so, this could result in 

the calculation of an unrealistically low MDL. In this case the MDL 

determination should be repeated using a lower concentration. Although

data can be reported down to the MDL, the associated variability (RSD 

$ 30%) at the MDL concentration is very high. A more realistic reporting

limit is the estimated upper limit of the 95% confidence interval about the 

MDL. This limit is based on the 97.5 percentile of chi square over

associated 6 degrees of freedom and is computed by multiplying the MDL

by a factor of 2.2(8). Typical single laboratory MDLs and reporting limits 

values using this method are given in Table 4. 

The MDLs must be sufficient to meet data quality needs and detect analytes

at the required levels according to compliance monitoring regulation

(Sect. 1.2). Specifically, the determined MDLs for the analytes: As, Be,

Cd, Sb, Se and Pb must be # 1/5 their respective MCL or action level

before this method can be used for compliance monitoring. MDLs should 

be determined as required for laboratory certification, when a new operator

begins work or whenever, in the judgment of the analyst, a change in

analytical performance caused by either a change in instrument hardware or 

operating conditions would dictate they be redetermined. 

9.3 Assessing Laboratory Performance (mandatory) 

9.3.1 Laboratory reagent blank (LRB) - The laboratory must analyze at least one

LRB (Sect. 7.9.2) with each batch of 20 or fewer samples. LRB data are 

200.5-19
used to assess contamination from the laboratory environment. LRB values 

that exceed the MDL indicate laboratory or reagent contamination should 

be suspected. When LRB values for the trace analytes are above the

calculated reporting limit (2.2 times the analyte MDL), fresh aliquots of the 

samples must be prepared and analyzed again for the affected analytes after

the source of contamination has been corrected and acceptable LRB values

have been obtained. 

9.3.2 Laboratory fortified blank (LFB) - The laboratory must analyze at least one

LFB (Sect. 7.9.3) with each batch of samples. Calculate accuracy as

percent recovery using the following equation: 

LFB 

R = S)))))))))Q X 100 

s 

where: R = percent recovery. 

LFB = laboratory fortified blank determined concentration. 

s = concentration equivalent of analyte added to fortify

the LRB solution. 

If the recovery of any analyte falls outside the required control limits of 

90-110%, that analyte is judged to be out of control, and the source of the

problem should be identified and resolved before continuing analyses. 

9.3.3 The laboratory must use LFB analyses data to assess laboratory

performance against the appropriate required control limits of 90-110% 

(see Sect.9.3.2). When sufficient internal performance data become 

available (usually a minimum of twenty to thirty analyses), optional control

limits can be developed from the mean percent recovery (x) and the

standard deviation (S) of the mean percent recovery. These data can be 

used to establish the upper and lower control limits as follows: 

UPPER CONTROL LIMIT = x + 3S 

LOWER CONTROL LIMIT = x ! 3S 

The optional control limits must be equal to or better than the appropriate

required control limits. After each five to ten new recovery measurements, 

new control limits can be calculated using only the most recent twenty to

thirty data points. Also, the standard deviation (S) data should be used to

establish an on-going precision statement for the level of concentrations 

included in the LFB. These data must be kept on file and be available for

review. 

9.3.4 Instrument performance check (IPC) solution - The laboratory must initially

and periodically verify that the instrument calibration is within required

control limits. For all determinations the laboratory must analyze the IPC

solution (Sect. 7.10.3) and a portion of the calibration blank immediately 

200.5-20
following calibration, after every tenth sample and at the end of the sample 

run. Analysis of the calibration blank should always be less than the

calculated reporting limit (2.2 times the analyte MDL) for the trace

elements. Analysis of the IPC solution immediately following calibration 

must verify that the instrument is within ± 5% of calibration. Subsequent

analyses of the IPC solution must be within ± 10% of calibration. If the 

calibration can not be verified within the specified limits, reanalyze both

the IPC solution and the calibration blank. If the second analysis confirms 

calibration to be outside the limits, sample analysis must be discontinued, 

the cause determined, corrected and/or the instrument recalibrated. All 

samples following the last acceptable IPC solution analysis must be 

reanalyzed. The analyses data of the IPC solution should be kept on file

with the sample analyses data. 

9.3.5 Spectral interference check (SIC) solution - For this method using the listed

wavelengths, the specified background locations, and an instrument with 

first order resolution of 0.016 nm or better, verification of interelement 

spectral interference is not required. However, if method flexibility,

allowing the use of different wavelengths, spectral orders, and background

correction locations requires an interelement correction routine for spectral

interference, it must be verified daily with the use of SIC solutions

(see Sect. 4.1 for listed criteria and description of required testing). 

9.4 Assessing Total Recoverable Analyte Recovery and Data Quality 

9.4.1 Sample non-homogeneity and the chemical nature of the sample matrix can 

affect analyte recovery and the quality of the data. In the analysis of

finished drinking water, these aspects are rarely an issue. However, source 

water for a drinking water supply can have varying turbidity. Taking

separate aliquots from the sample for replicate and fortified analyses can, in 

some cases, assess the effect. Unless otherwise specified by the data user,

laboratory or program, the following laboratory fortified matrix (LFM)

procedure (Sect. 9.4.2) is required. 

9.4.2 The laboratory must add a known amount of each analyte to a minimum of 

10% of the routine samples. The LFM aliquot must be a duplicate of the

aliquot used for sample analysis and fortified prior to sample preparation.

The added analyte concentration must be the same as that used in the 

laboratory fortified blank (Sect. 7.9.3). Over time, samples from all routine 

sample sources should be fortified. 

9.4.3 Calculate the percent recovery for each analyte, corrected for analyte

background concentrations greater than the calculated reporting limit 

measured in the unfortified sample, and compare these values to the 

designated LFM recovery range of 85-115%. Percent recovery may be

calculated using the following equation: 

200.5-21
 Cs - C 

R = S))))))Q x 100 

s 

where: R = percent recovery.

Cs = fortified sample concentration. 

C = sample background concentration (>2.2 X MDL). 

s = concentration equivalent of analyte

added to fortify the sample. 

9.4.4 If the recovery of any analyte falls outside the designated LFM recovery

range, and the laboratory performance for that analyte is shown to be in

control (Sect. 9.3), the recovery problem encountered with the fortified 

sample is judged to be matrix related, not system related. If the analyte in

question is a primary contaminant (Sect. 1.1), under certain circumstances 

additional analyses may be required (see Sects. 1.6 and 1.7). For a primary 

contaminant not requiring additional analysis, for a secondary contaminant, 

or non-regulated analyte, the data user should be informed that the result 

for that analyte is suspect due to matrix effects. 

9.4.5 Where reference materials are available, they should be analyzed to provide

additional performance data. The analysis of reference samples is a 

valuable tool for demonstrating the ability to perform the method 

acceptably. 

10.0 CALIBRATION AND STANDARDIZATION 

10.1 Specific wavelengths and calibration concentrations are listed in Table 1. Other 

wavelengths may be substituted if they can provide the needed sensitivity and are

corrected for spectral interference (see Sect. 4.1). However, because of the 

difference among various makes and models of spectrometers, specific instrument 

operating conditions are not required. The instrument and operating conditions

utilized for determination must be capable of providing data of acceptable quality

(see Sect. 1.12) to the drinking water program and data user. The analyst should

follow the instructions provided by the instrument manufacturer; however, 

instrument operating conditions used to collect the single laboratory performance 

data included in this method are listed in Table 3 and are provided as a 

recommendation. Once operating conditions are established, it is intended that daily

calibration will be accomplished using a calibration blank and a single analyte

concentration. 

10.2 Prior to using this method, optimize the plasma operating conditions. The purpose

of plasma optimization is to provide a maximum net signal-to-background ratio

(S-B/B) for the determination of As and Sb, the most requiring elements in the 

analytical array. The use of a mass flow controller to regulate or monitor the 

nebulizer gas flow rate greatly facilitates the procedure. The following procedure is 

recommended: 

200.5-22
10.2.1 Ignite the plasma, and using the conditions listed in Table 3 as a guide,

select appropriate incident rf power and plasma gas flows. Allow the 

instrument to become thermally stable before beginning. This usually

requires approximately 30 minutes of operation. Set the aerosol argon flow

rate through the nebulizer at approximately 650 mL per minute or at the 

instrument manufacturer’s recommended pressure setting if the flow rate

can not be measured. Following the instrument manufacture’s instructions, 

optically profile the instrument to provide maximum signal for all

wavelengths. While aspirating reagent water and using the As channel

signal, adjust the horizontal and vertical position of the torch to provide 

minimum signal intensity. This should align the optics with the center of

the sample channel of the plasma and minimize background noise. 

10.2.2 After profiling the torch, aspirate the plasma solution (Sect. 7.11) and while

following the instrument manufacturer's instructions, adjust the aerosol

carrier gas flow rate through the nebulizer and collect signal intensity

readings (S) at equal incremental flow settings on either side of the initial 

flow rate setting. Suggested flow rates (mL/min) settings are: 590, 600, 

610, 620, 630, 640, 650, 660, 670, 680, 690 and 700. (NOTE: If nebulizer

flow rates can not be measured, incremental pressure settings that control

flow should be used.) After acid rinsing to eliminate any possible memory

effect, repeat the same operation using an acid blank solution and collect

the blank signal intensity readings (B) at the same respective flow settings.

Calculate the S-B/B ratio for As and Sb at each flow setting. Plot, on the 

same graph, the calculated ratios and the blank intensity readings versus the

argon flow rates. The intensity counts for the blank signal should decrease

at a uniform rate as the argon flow rate increases, while the calculated

S-B/B ratios for Sb should increase. At the lower flow rate settings, the As

ratios should remain nearly constant; however, at some point the As ratio

will start to decrease with an increase in flow rate. The flow rate where the 

As ratio begins to decrease (2% or more) is the limiting flow and the flow

rate just prior to the limiting flow should be selected for routine operation.

Record the nebulizer gas flow rate or pressure setting for future reference.

If the nebulizer is replaced with a new or different nebulizer, repeat this

optimization procedure. 

10.2.3 After establishing the nebulizer gas flow rate, determine the solution uptake

rate of the nebulizer in mL/min by aspirating a known volume calibration 

blank for a period of at least 3 minutes. Divide the spent volume by the

aspiration time (in minutes) and record the uptake rate. Set the peristaltic 

pump to deliver the uptake rate in a steady even flow. 

10.2.4 The final instrument operating condition, selected as being optimum, 

should provide acceptable instrument detection limits and method detection 

limits for all trace analytes. Refer to Table 4 for comparison of IDLs and 

MDLs, respectively. 

10.2.5 Before daily calibration and after the instrument warmup period, the 

200.5-23
nebulizer gas flow should be reset to the determined optimized flow. If a 

mass flow controller is being used, it should be reset to the recorded

optimized flow rate. In order to maintain reliable MDLs, the nebulizer gas

flow rate should be the same from day-to-day (<2% change). 

10.3 Before using the procedure (Sect. 11.0) to analyze samples, there must be data 

available documenting initial demonstration of performance. The required data and

procedures are described in Sections 9.2.2, 9.2.3, 9.2.4, and 9.2.5. These data must 

be generated using the same instrument operating conditions and respective

calibration routines used for sample analysis (see Sect. 11.2). These documented 

data must be kept on file and be available for review by the data user. 

10.4 After completing the initial demonstration of performance, but before analyzing 

samples, the laboratory, if needed, must establish and initially verify the 

interelement spectral interference correction routine to be used during sample 

analysis. A general description concerning spectral interference and the analytical

requirements for background correction are given in Sections 4.1 and 9.3.5. Once 

established, the entire routine must be verified on a daily basis by analyzing SIC

solution(s) resulting in response data that falls within the 3-sigma control limits of 

the calibration blank of the analyte (Sect. 4.1). 

11.0 PROCEDURE 

11.1 Sample Preparation (Total Recoverable Digestion) - For the determination of trace 

analytes and water matrix elements in drinking water and source water supply, using

a 50-mL PMP graduated cylinder, transfer a 50 mL (± 0.5 mL) aliquot from a wellmixed, acid preserved sample to a 50-mL clean digestion tube containing a mixture 

of 1.0 mL (1+1) HNO3 (Sect. 7.3.1) and 0.5 mL (1+1) HCl (Sect. 7.2.1). (The acids

should be added to the digestion tube using an air displacement pipetter - see Sect.

6.6.) Place the digestion tube in the block digester (Sect. 6.4). (The block digester

should be located in a clean fume hood.) Power the digestion block to preselected

settings to evaporate the sample at a temperature of 95 °C (± 2 °C). Preconcentrate 

the sample until the volume has been reduced to approximately 25 mL. Cover the 

digestion tube with a plastic watch glass and reflux the sample for 30 minutes. (The

time required to complete this step should approximate 2.5 h.) Once the refluxing

step is complete, remove the digestion tube from the block digester and allow the 

sample to cool. When cool, using the volume gradation marks on the digestion tube,

adjust the sample volume to 25 mL with reagent water (Sect. 7.4). Cap the digestion

tube and mix. The sample is now ready for analysis. Because the effects of various 

matrices on the stability of analytes in low concentration can not be characterized,

all analyses should be performed as soon as possible after the completed 

preparation. 

11.2 Sample Analysis 

11.2.1 Prior to daily calibration of the instrument, inspect the sample introduction 

system, including the nebulizer, torch, injector tube and uptake tubing, for

salt deposits, dirt and debris that would restrict solution flow and affect 

200.5-24
instrument performance. Clean the system when needed or on a daily basis. 

11.2.2 Configure the instrument system to the selected power and operating

conditions as determined in Sections 10.1 and 10.2. 

11.2.3 The instrument should be allowed to become thermally stable before

calibration and analyses. This usually requires at least 30 minutes of 

operation. After instrument warmup, complete any required optical

profiling or alignment routines particular to the instrument. 

11.2.4 For initial and daily operation, calibrate the instrument according to the

instrument manufacturer's recommended procedures, using mixed 

calibration standard solutions (Sect. 7.8.1) and the calibration blank

(Sect. 7.9.1). A peristaltic pump must be used to introduce all solutions to 

the nebulizer. To allow equilibrium to be reached in the plasma, aspirate

all solutions for 20 sec after reaching the plasma before beginning

integration of the background corrected signal to accumulate data. To 

reduce measurement variance, use the average value of replicate integration

periods of the signal to be correlated to analyte concentration. (Suggested

data collection period for all determinations: 5 replicate 24 sec periods [8

sec on the wavelength peak and 8 sec on each BKGD location] = 120 sec.)

Flush the system with the rinse blank (Sect. 7.9.4) for a minimum of 30 

seconds (Sect. 4.4) between each standard. 

11.2.5 After completion of the initial requirements of this method (Sects. 10.3 and

10.4), samples should be analyzed in the same operational manner used in 

the calibration routine with the rinse blank also being used between all 

sample solutions and quality control check solutions. 

11.2.6 During sample analysis the laboratory must comply with the required

quality control described in Sections 9.3 and 9.4. 

11.2.7 Determined water matrix element concentrations that are 90% or more of 

the upper limit of the analyte LDR, or in the case of Na above the multipoint calibration range, must be diluted with reagent water that has been

acidified in the same manner as the calibration blank and reanalyzed. 

11.2.8 To ensure an accurate determination for compliance monitoring, a primary 

contaminant must be reanalyzed by either method of standard additions 

(see Sect.11.3), or by another approved method, when the concentration of 

that primary contaminant determined by the normal analytical routine

(Sect. 11.2) is $ 80% of the established MCL, or action level, and the 

required LFM analysis does not verify the absence of a matrix interference 

(see Sects. 1.6 & 9.4). 

11.2.9 Report data as directed in Section 12. 

11.3 If the method of standard additions (MSA) is used, standards are added at one or 

200.5-25
more levels to portions of a prepared sample. This technique(9) compensates for 

enhancement or depression of an analyte signal by a matrix. It will not correct for 

additive interferences such as contamination, interelement interferences, or baseline 

shifts. This technique is valid in the linear range when the interference effect is 

constant over the range, the added analyte responds the same as the endogenous

analyte, and the signal is corrected for additive interferences. The simplest version 

of this technique is the single-addition method. This procedure calls for two

identical aliquots of the sample solution to be taken. To the first aliquot, a small 

volume of standard is added, while to the second aliquot, a volume of acid blank is 

added equal to the standard addition. The sample concentration is calculated by the

following: 

S2 x V1 x C 

Sample Conc = S)))))))))))Q

μg/L (S1-S2) x V2 

where: C = Concentration of the standard solution (μg/L)

S1 = Signal for fortified aliquot

S2 = Signal for unfortified aliquot

V1 = Volume of the standard addition (L)

V2 = Volume of the sample aliquot (L) used for MSA 

12.0 DATA ANALYSIS AND CALCULATIONS 

12.1 Sample data for the water matrix elements (Ca, Mg and Na) and silica should be

reported in units of mg/L. For compliance monitoring, total recoverable trace

elements should be reported in the same units used to express the MCL or action

level. If there is no established MCL, the trace element should be reported in μg/L. 

12.2 For water matrix analytes, multiply the solution analyte concentrations by the

dilution factor, 0.5, and report the data with allowance for sample dilution when 

analyte concentrations exceed 90% or more of the LDR upper limit, and in the case 

of Na when the analytical range is exceeded. Round the data to the thousandth place

and report up to three significant figures. Do not report analyte concentrations

below the IDL. 

12.3 For total recoverable trace element analytes, multiply solution analyte

concentrations by the dilution factor 0.5, round off the data values (μg/L) to the

nearest tenths place and report analyte concentrations up to three significant figures.

For drinking water compliance monitoring, do not report data below the analyte

reporting limit calculated from the laboratory determined MDL data (see Sect.

9.2.5). Typical MDLs and calculated reporting limits are given in Table 4. 

12.4 The QC data obtained during the analyses provide an indication of the quality of the 

sample data and should be provided with the sample results. 

200.5-26
13.0 METHOD PERFORMANCE 

13.1 Listed in Table 4 are typical single laboratory total recoverable MDLs for the 

sample procedure given in Sections 11.1, followed by analysis using pneumatic 

nebulization. They were determined for the recommended wavelengths using

simultaneous AVICP-AES and the operating conditions given in Table 3. The 

MDLs were determined in reagent blank matrix (best case situation) fortified with 

the respective analyte concentration also listed in Table 4. 

13.2 Data obtained from single laboratory method testing are summarized in Tables 5 and 

6. Table 5 lists precision (RSD) and average recovery data for SRM 1643c that was

analyzed along with the drinking water samples listed in Table 6. The drinking 

water samples were prepared using the procedure given in Section 11.1. Table 6 

lists data for 4 different tap water matrices (two well water supplies, one surface

water supply, and a home cistern supply). Five unfortified aliquots were prepared to

determine sample background concentrations and four aliquots for each LFM. For 

primary and secondary contaminants, the LFMs were fortified to a concentration 

equivalent to the respective analyte MCL. Data for the analysis of the water matrix 

elements and silica are listed at the bottom of sample data sheet. 

14.0 POLLUTION PREVENTION 

14.1 Pollution prevention encompasses any technique that reduces or eliminates the 

quantity or toxicity of waste at the point of generation. Numerous opportunities for

pollution prevention exist in laboratory operation. The EPA has established a 

preferred hierarchy of environmental management techniques that places pollution

prevention as the management option of first choice. Whenever feasible, laboratory

personnel should use pollution prevention techniques to address their waste

generation (e.g., Sect. 7.7). When wastes cannot be feasibly reduced at the source,

the Agency recommends recycling as the next best option. 

14.2 For information about pollution prevention that may be applicable to laboratories

and research institutions, consult Less is Better: Laboratory Chemical Management

for Waste Reduction, available from the American Chemical Society's Department 

of Government Relations and Science Policy, 1155 16th Street N.W., Washington

D.C. 20036, or on-line at http://membership.acs.org/c/ccs/pub_9.htm. 

15.0 WASTE MANAGEMENT 

15.1 The Environmental Protection Agency requires that laboratory waste management 

practices be conducted consistent with all applicable rules and regulations. The 

Agency urges laboratories to protect the air, water, and land by minimizing and

controlling all releases from hoods and bench operations, complying with the letter

and spirit of any sewer discharge permits and regulations, and by complying with all

solid and hazardous waste regulations, particularly the hazardous waste

identification rules and land disposal restrictions. For further information on waste 

management consult The Waste Management Manual for Laboratory Personnel, 

available from the American Chemical Society at the address listed in the 

200.5-27
Section 14.2. 

16.0 REFERENCES 

1. U.S. Environmental Protection Agency. Sample Preparation Procedure for

Spectrochemical Determination of Total Recoverable Elements - Method 200.2, 

Revision 2.8, May 1994 (EPA-600/R-94/111). 

2. U.S. Environmental Protection Agency. Determination of Trace Elements by

Stabilized Temperature Graphite Furnace Atomic Absorption - Method 200.9,

Revision 2.2, May 1994 (EPA-600/R-94/111). 

3. Carcinogens - Working With Carcinogens, Department of Health, Education, and 

Welfare, Public Health Service, Center for Disease Control, National Institute for 

Occupational Safety and Health, Publication No. 77-206, Aug. 1977. Available from

the National Technical Information Service (NTIS) as PB-277256. 

4. OSHA Safety and Health Standards, General Industry, (29 CFR 1910), Occupational

Safety and Health Administration, OSHA 2206, (Revised, January 1976). 

5. Safety in Academic Chemistry Laboratories, American Chemical Society

Publication, Committee on Chemical Safety, 3rd Edition, 1979. 

6. American Society for Testing and Materials. Standard Specification for Reagent

Water, D1193-77. Annual Book of ASTM Standards, Vol. 11.01. Philadelphia, PA,

1991. 

7. Code of Federal Regulations 40, Ch. 1, Pt. 136 Appendix B. 

8. Glaser, J.A.,D.L. Foerst, G.D. McKee, S.A. Quave, and W.L. Budde, “Trace 

Analyses for Wastewaters,” Environ. Sci. Technol., 15 (1981) 1426-1435. 

9. Winefordner, J.D., Trace Analysis: Spectroscopic Methods for Elements, Chemical 

Analysis, Vol. 46, pp. 41-42. 

200.5-28
17.0 TABLES, DIAGRAMS, FLOWCHARTS, AND VALIDATION DATA 

TABLE 1. WAVELENGTHS, BACKGROUND CORRECTION LOCATIONS, 

AND RECOMMENDED CALIBRATION 

W444444444444444444444444444444444444444444444444444444444444444444444U

Location 

For BKGD. Calibrateb 

Analyte Wavelengtha Correction to 

(nm) (nm) (mg/L) 

Aluminum

Antimony

Arsenic

Barium

Beryllium

Boron

Cadmium

Calcium

Chromium

Copper

Iron

Lead

Magnesium

Manganese

Nickel

Selenium

Silica (SiO2)

Silver

Sodium

Tin

Vanadium

Zinc

308.215 +0.033 5 

206.833x2 -0.009 0.5 

189.042x2 -0.009 0.5 

493.409 +0.033 1 

313.042 +0.033 0.1 

249.678x2 +0.016 1 

226.502x2 +0.016 0.1 

315.887 +0.033 20 

267.716 +0.033 0.5 

324.754 +0.033 2 

271.441 +0.033 5 

220.353x2 +0.016 0.5 

279.079 +0.033 20 

257.610 +0.033 0.5 

231.604x2 +0.016 0.5 

196.090x2 -0.009 0.5 

251.611 +0.033 21.4 

328.068 +0.033 0.1 

330.232 +0.033 20 

189.980 -0.018 0.2 

292.402 +0.033 0.5 

206.200 +0.033 0.5 

W444444444444444444444444444444444444444444444444444444444444444U

a The wavelengths listed in the noted spectral order are recommended because of their 

sensitivity and overall acceptability. Other wavelengths may be substituted if they can

provide the needed sensitivity and are treated with the same corrective techniques for 

spectral interference (see Sect. 4.1). 

b Suggested concentration for instrument calibration. Other calibration limits in the linear 

ranges may be used. 

200.5-29
TABLE 2. MIXED STANDARD SOLUTIONS

Solutiona Analytes 

I As, Be, Cd, Pb, Sb, Se, V, and Zn

II Ba, Cr, Fe, Mn, Ni, Sn, and SiO2

III Al, Cu, Ca, Mg, and Na

IV Ag and B 

a See Section 7.8.1 

TABLE 3. AXIALLY VIEWED INDUCTIVELY COUPLED PLASMA 

INSTRUMENT OPERATING CONDITIONS 

rf power 950 watts 

Argon supply liquid argon 

Argon pressure 60 psi 

Coolant argon flow rate 20 L/min 

Aerosol carrier argon 

pressure 27 psi

flow rate 635 mL/min 

Auxiliary (plasma)

argon flow rate 0.5 L/min 

Sample uptake rate

controlled to 1.6 mL/min 

200.5-30
TABLE 4. DETECTION AND REPORTING LIMITS 

INSTRUMENT(a) MDL METHOD CALCULATED(b) 

DETECT. LIMIT SPIKE DETECTION LIMIT REPORTING 

ANALYTE g/L 

Ag - 0.2 0.5 0.2 0.5 

Al - 3 4.0 2.2 4.9 

As - 2 2.5 1.4 3.1 

B - 0.5 0.8 0.3 0.7 

Ba - 0.03 0.08 0.05 0.2 

Be - 0.03 0.04 0.02 0.1 

Ca 0.02 - - - -

Cd - 0.2 0.4 0.1 0.3 

Cr - 0.2 0.4 0.2 0.5 

Cu - 0.2 0.4 0.3 0.7 

Fe - 5 10 3.3 7.3 

Mg 0.02 - - - - Mn - 0.07 0.08 0.06 0.2 

Na 0.4 - - - - Ni - 0.6 1.3 0.6 1.4 

Pb - 1 3.0 1.1 2.5 

Sb - 1 2.0 0.9 2.0 

Se - 2 3.0 1.3 2.9 

SiO2 0.01 - - - -

Sn - 1 1.0 0.5 1.1 

V - 0.2 0.6 0.2 0.5 

Zn - 0.4 0.6 0.4 0.9 

m μg/L μg/L (MDL), μg/L LIMIT, μg/L 

a Instrument detection limits are used as reporting limits for matrix elements. 

b The listed calculated reporting limits have been rounded up to the tenths place to fully meet the 

2.2 multiple criteria and to eliminate the listing of insignificant numbers. Because of rounding

up to the tenths place, the reporting limits listed for Ba and Be are multiples of 4 and 5 times 

their respective MDLs. 

200.5-31
TABLE 5. SRM(1643c) PRECISION AND ACCURACY DATA 

NIST - 1643c DETERMINED AVERAGE 

CERTIFIED VALUE CONC. STD. RECOVERY RSD 

Ag 2.21 2.1 0.82 95% 

Al 114.6 125 5.1 

As 82.1 83.7 1.9 

B 119.0 114 0.5 96% 

Ba 49.6 49.2 99% 

Be 23.2 22.5 97% 

Cd 12.2 11.9 0.13 

Cr 19.0 18.0 0.21 103% 

Cu 22.3 22.9 99% 

Fe 106.9 106 2.8 99% 

Mn 35.1 34.5 98% 

Ni 60.6 57.4 95% 

Pb 35.3 34.4 97% 

Se 12.7 11.9 94% 

V 31.4 28.3 

Zn 73.9 74.4 0.52 

μg/L μg/L 

± 0.30 3.9% 

± 5.1 109% 4.1% 

± 1.2 102% 2.2% 

± 1.4 0.4% 

± 3.1 0.52 1.0% 

± 2.2 0.33 1.5% 

± 1.0 98% 1.1% 

± 0.6 1.2% 

± 2.8 0.74 3.2% 

± 3.0 2.7% 

± 2.2 0.4 1.2% 

± 7.3 0.58 1.0% 

± 0.9 1.2 3.5% 

± 0.7 0.7 5.9% 

± 2.8 0.15 93% 0.5% 

± 0.9 101% 0.7% 

ANALYTE DEV. % % 

NIST - 1643c DETERMINED AVERAGE 

CERTIFIED VALUE CONC. STD. RECOVERY RSD 

ANALYTE mg/L mg/L DEV. % % 

Ca 36.8 37.0 101% 0.9% 

Mg 9.45 9.61 0.16 102% 1.6% 

Na 12.19 12.6 103% 0.7% 

± 1.4 0.32

± 0.27

± 0.36 0.09

200.5-32
TABLE 6. TRACE ELEMENT PRECISION AND RECOVERY DATA 

TAP WATER - REGION 5 SURFACE WATER SUPPLY 

__________________________________________________________________________________ 

SAMPLE 

CONC. STD. Spike

ANALYTE μg/L DEV. μg/L 

AVERAGE 

RECOVERY 

(%) 

RSD 

(%) 

Ag <0.5 - 100 100 1.2 

Al 18 1.3 200 105 1.5 

As <3.1 - 10.0 105 4.2 

B 34.8 0.9 100 101 1.5 

Ba 37.7 0.4 2000 100 1.3 

Be <0.1 - 4.0 100 1.4 

Cd <0.3 - 5.0 98 1.8 

Cr <0.5 - 100 99 1.3 

Cu 3.3 0.09 1000 101 1.3 

Fe <7.3 - 300 99 1.5 

Mn 0.4 0.01 50 98 1.1 

Ni 1.5 0.1 100 99 1.0 

Pb <2.5 - 15.0 100 2.2 

Sb <2.0 - 6.0 100 5.3 

Se <2.9 - 50 104 2.0 

Sn <1.1 - 50 102 2.0 

V <0.5 - 50 100 1.4 

Zn 5.6 0.1 2000 99 1.0 

< Sample concentration below the calculated reporting limit. 

Analysis of Water Matrix Elements 

Sample RSD 

Analyte Conc. mg/L (%) 

Ca 34.6 1.4 

Mg 9.64 1.6 

Na 26.4 2.9 

SiO2 5.23 1.6 

200.5-33
TABLE 6. TRACE ELEMENT PRECISION AND RECOVERY DATA (Cont’d.) 

TAP WATER - REGION 5 WELL WATER SUPPLY 

__________________________________________________________________________________ 

SAMPLE 

CONC. STD. Spike

ANALYTE μg/L DEV. μg/L 

AVERAGE 

RECOVERY 

(%) 

RSD 

(%) 

Ag <0.5 - 100 97 1.2 

Al <4.9 - 200 103 1.1 

As 17.7 0.3 10.0 101 1.2 

B 96.0 0.7 100 102 0.9 

Ba 107 0.7 2000 97 1.0 

Be <0.1 - 4.0 97 1.4 

Cd <0.3 - 5.0 96 1.9 

Cr <0.5 - 100 93 1.3 

Cu <0.7 - 1000 98 1.1 

Fe 552 2.7 300 103 1.1 

Mn 15.0 0.1 50 95 1.1 

Ni <1.4 - 100 94 1.3 

Pb <2.5 - 15.0 97 4.7 

Sb <2.0 - 6.0 97 7.4 

Se <2.9 - 50 101 1.2 

Sn <1.1 - 50 102 1.2 

V <0.5 - 50 95 1.3 

Zn 6.2 0.36 2000 95 1.5 

< Sample concentration below the calculated reporting limit. 

Analysis of Water Matrix Elements 

Sample RSD 

Analyte Conc. mg/L (%) 

Ca 69.9 0.6 

Mg 28.0 0.7 

Na 57.9 1.9 

SiO2 12.3 0.8 

200.5-34
TABLE 6. TRACE ELEMENT PRECISION AND RECOVERY DATA (Cont’d.) 

TAP WATER - REGION 6 WELL WATER SUPPLY 

__________________________________________________________________________________ 

SAMPLE 

CONC. STD. Spike

ANALYTE μg/L DEV. μg/L 

AVERAGE 

RECOVERY 

(%) 

RSD 

(%) 

Ag <0.5 - 100 100 1.2 

Al <4.9 - 200 102 1.6 

As <3.1 - 10.0 101 2.3 

B 56.4 1.2 100 104 1.4 

Ba 203 3.6 2000 100 1.4 

Be <0.1 - 4.0 102 1.4 

Cd <0.3 - 5.0 96 1.9 

Cr 1.3 0.07 100 96 1.1 

Cu 155 2.7 1000 100 1.3 

Fe 8.6 1.9 300 96 1.7 

Mn 0.6 0.02 50 97 1.3 

Ni 3.3 0.2 100 98 1.4 

Pb <2.5 - 15.0 105 2.5 

Sb <2.0 - 6.0 98 3.6 

Se 4.1 0.5 50 100 1.1 

Sn 4.4 0.1 50 102 1.0 

V 11.5 0.2 50 98 1.4 

Zn 26.4 0.5 2000 98 1.4 

< Sample concentration below the calculated reporting limit. 

Analysis of Water Matrix Elements 

Sample RSD 

Analyte Conc. mg/L (%) 

Ca 44.6 1.6 

Mg 9.26 1.6 

Na 41.0 1.7 

SiO2 26.2 1.6 

200.5-35
TABLE 6. TRACE ELEMENT PRECISION AND RECOVERY DATA (Cont’d.) 

TAP WATER - CISTERN WATER SUPPLY 

__________________________________________________________________________________ 

SAMPLE 

CONC. STD. Spike

ANALYTE μg/L DEV. μg/L 

AVERAGE 

RECOVERY 

(%) 

RSD 

(%) 

Ag <0.5 - 100 98 1.2 

Al 31.3 0.9 200 104 1.7 

As <3.1 - 10.0 102 7.8 

B 6.6 0.2 100 100 1.2 

Ba 3.3 0.05 2000 98 1.4 

Be <0.1 - 4.0 96 1.2 

Cd <0.3 - 5.0 94 1.1 

Cr <0.5 - 100 95 1.1 

Cu 262 1.5 1000 99 1.7 

Fe 13 1.9 300 95 1.3 

Mn 0.6 0.01 50 94 1.2 

Ni <1.4 - 100 95 1.7 

Pb <2.5 - 15.0 101 1.6 

Sb <2.0 - 6.0 103 3.2 

Se <2.9 - 50 95 1.2 

Sn <1.1 - 50 95 1.6 

V <0.5 - 50 97 1.3 

Zn 14.2 3.4 2000 95 1.2 

< Sample concentration below the calculated reporting limit. 

Analysis of Water Matrix Elements 

Sample RSD 

Analyte Conc. mg/L (%) 

Ca 10.1 0.7 

Mg 0.68 1.0 

Na 2.3 1.1 

SiO2 2.07 0.6 

200.5-36