The analyst is required to analyze a number of QC samples throughout the run where there are decisions to be made based on a window of acceptance for each QC sample analyzed.

2. 2
• Introduction
• Quality control
• ICP QC Criteria
• ICP Checks Software
Contents

3. 3
ICP
An inductively coupled plasma
• Is a plasma that is energized (ionized)
by inductively heating the gas with
an electromagnetic coil, and contains a
sufficient concentration of ions
and electrons to make the gas electrically
conductive

4. 4
ICP Mechanism
• Samples are nebulized and the resulting aerosol is
transported 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.
• Photocurrents from the photosensitive device are
processed and controlled by a computer system.

6. 6
Quality
It is the best possible expected outcome of an effort under given
conditions and terms of skill, experience, financial and available
resources.
QC (Quality Control)
Is the type of system/s or programs that are specifically
applied to ensure the conformity of the results (outcome,
products) to established criteria or standards.
QA (Quality Assurance)
Is the total efforts and activities by a group of specialists to achieve
quality results (products, outcome)
TQM (Total Quality Management)
Is the continued observation and monitoring by the institution of all
sections and groups under a specific task or mission to meet the set
Goals of Quality for the institution.
Quality

7. 7
QC & QA
Quality control
The maintenance and statement of the quality of a
product (data set, etc.) specifically that it meets or
exceeds some minimum standard based on known,
testable criteria.
Quality assurance
The guarantee that the quality of a product (analytical
data set, etc.) is actually what is claimed on the basis of
the quality control applied in creating that product.
• Quality assurance is not synonymous with quality control.
• Quality assurance is meant to protect against failures of quality control.

8. 8
Accuracy
• The degree of agreement of test results with the
true value or the closeness of the results obtained
by the procedure to the true value. Or
• How close results are to true values.
• Accuracy is usually reported as a percentage of the
observed value divided by the reference value
(percent recovery) using the following equation:
%R = observed value X 100
reference value
Where %R = percent recovery

9. 9
Accuracy verification
To verified the accuracy of laboratory it should check;
• Laboratory Control Samples (LCS)
• Matrix Spikes and Matrix Spike Duplicates (MS & MSD)
• Internal Standards (IS)
• Initial Calibration (IC)
• Continuing Calibration (CC)
• Standard Reference Material (SRM)

10. 10
Precision
• Precision is a measure of the reproducibility of
sample results. Or
• How close results are to each other
• Precision is measured through the calculation of the
relative percent difference (RPD) of two data sets
generated from a similar source or percent relative
standard deviation (%RSD) from multiple sets of data.
RSD = ( s/ X) × 100
Where s is the standard deviation &
X is mean of replicate samples

11. 11
Precision Verification
• Laboratory Control Sample/
• Laboratory Control Sample
Duplicate Pair
• Matrix Spike Duplicates
• Historical Data Trends
To verified the precision of laboratory it should check;

12. 12
Bias
• Bias is the ± deviation of the measured value from
the true value.
• This can be analytical bias within the analytical
procedure, or it can be due to matrix effects.
• There is inherent bias within all analytical
procedures.
• Quality control measurement tools that can be
used to evaluate bias include laboratory control
samples, check standards, matrix spikes, or any
other standards used for analysis.

13. The analyst is required to analyze a
number of QC samples throughout the
run where there are decisions to be made
based on a window of acceptance for each
QC sample analyzed.

14. 14
QC Criteria for ICP
1. Preservation and Holding Times
2. Calibration
3. Blanks
4. Interference Check Sample (ICS)
5. Laboratory Control Sample (LCS)
6. Duplicate Sample Analysis
7. Spike Sample Analysis
8. Serial Dilution
9. Quality Assurance (QA) and Quality Control (QC)

15. 15
1. Preservation and Holding Times
• If properly acid preserved, the sample( Aqueous /
water, Wipe and air filter, Soil and Sediments) can
be held up to six months before analysis.
• Acidify the filtrate with (1+1) nitric acid immediately
following filtration to pH <2.
• For the determination of total recoverable elements
in aqueous samples, samples are not filtered, but
acidified with (1+1) nitric acid to pH <2 (normally, 3
mL of (1+1) acid per liter of sample is sufficient for
most ambient and drinking water samples).

16. 16
2. Calibration
The set of operations which establish, under specified
conditions, the relationship between values indicated by
the analytical instrument and the corresponding known
values of an analyte.
2.1 Initial Calibration (IC)
2.2 Initial Calibration Verification (ICV)
2.3 Continuing Calibration Verification (CCV)

17. 17
2.1 Initial Calibration (IC)
The instruments shall be successfully calibrated each time the instrument is set up, and after
Continuing Calibration Verification (CCV) failure.
• The calibration date and time shall be included in the raw data.
• A blank and at least five calibration standards shall be used to establish each curve.
• All measurements shall be within the instrument working range where the interelement
correction factors are valid.
• A minimum of three replicate exposures are required for standardization.
• The calibration curve shall be fitted using linear regression or weighted linear regression.
• The curve may be forced through zero.
• The curve must have a correlation coefficient ≥ 0.995.
• The percent differences calculated for all of the non-zero standards must be within ±30%
of the true value of the standard.

18. 18
2.2 Initial Calibration Verification (ICV)
(ICV) demonstrates that the instrument is capable of acceptable performance at the
beginning of the analytical run.
• Immediately after system has been calibrated, the accuracy of the initial calibration must
be verified and documented for each target analyte by the analysis of an ICV solution(s).
• If the ICV %R falls outside of the control limits (10%), the analysis should be
terminated, the problem corrected, the instrument recalibrated, and all affected
samples reanalyzed.
• Analyses shall be conducted using a certified solution(another source), at a
concentration level other than that used for instrument calibration, but within the
calibrated range.
• The ICV solution shall be run at each analytical wavelength used for analysis.
• ICV is the same as the CCV but analyzed after calibration.

19. 19
2.3 Continuing Calibration Verification (CCV), (IPC)
(CCV) demonstrates that the initial calibration is still valid by checking the performance of the
instrument on a continuing basis. Instrument performance check (IPC) solution
• To ensure accuracy during the course of each analytical run, the CCV shall be analyzed and
reported for each wavelength used for the analysis of each analyte.
• The CCV standard shall be analyzed at a frequency of every two hours during an analytical
run, at the beginning of the run, and after the last analytical sample.
• The analyte concentration(s) in the CCV standard(s) shall be different than the
concentration used for the IC, and at mid range of curve.
• The CCV shall be analyzed in the same way as an actual sample.
• If the %R of the CCV was outside(±10%) of the control limits, the analysis should be
terminated, the problem corrected, the instrument recalibrated, and all analytical samples
analyzed since the last compliant CCV reanalyzed.

20. 20
RM & CRM
Reference Material (RM)
Material or substance one or more of whose property values are sufficiently
homogeneous, stable, and well established to be used for the calibration of an
apparatus, the assessment of a measurement method, or for assigning values to
materials.
Certified Reference Material (CRM)
Reference material, accompanied by a certificate, one or more of whose property
values are certified by a procedure which establishes its traceability to an accurate
realization of the unit in which the property values are expressed, and for which
each certified value is accompanied by an uncertainty at a stated level of confidence.
In-house Reference Material (in-house RM)
Reference material developed by a laboratory for its own internal use.
CRMs and in-house RMs are simply types of RMs.

21. 21
3. Blanks
The objective of blank analysis results assessment is to determine the existence and
magnitude of contamination resulting from laboratory (or field) activities.
A lot of blanks are required for the analysis according the methods.
• The calibration blank is used in establishing the analytical curve,
• The method blank is used to assess possible contamination from the sample
preparation procedure,
• The laboratory fortified blank is used to assess routine laboratory performance
• Rinse blank is used to flush the instrument uptake system and nebulizer between
standards, check solutions, and samples to reduce memory interferences.

22. 22
3.1 Laboratory Reagent Blank (LRB)
Method Blank , Preparation blank, Sample blank, Matrix Blank
• LRB Laboratory Reagent Blank Checks the laboratory reagents,
apparatus and sample preparation process for contamination 1 per
batch of 20 or fewer samples < 2.2 x MDL
• A blank prepared to represent the matrix as closely as possible.
• The method blank results must be less than the RL.
• A method blank containing an analyte concentration >RL may be
used in instances when the sample concentrations are at least 10
times the method blank concentration.

23. 23
Reporting Limits (RL) Solutions
The RL is the lowest concentration that a method can
achieve for a target analyte with the necessary
degree of accuracy and precision.
The RL for an inorganic compound is derived from the
concentration of that analyte in the lowest level
check standard (which could be the lowest
calibration standard in a multi-point calibration
curve).
RLs are method and laboratory-specific. Laboratories
are required to report the RLs for all compounds for
all samples

24. 24
3.2 Field Blank
• A field blank is a sample of uncontaminated reagent water which is free of the
analyte of interest.
• This sample is prepared by the laboratory and is taken to the sampling site,
opened and exposed to the sampling environment while the sampling is
performed, preserved as necessary then closed and returned to the laboratory
for analysis.
• This type of QC sample will identify environmental contamination from the field
and/or laboratory such as extraneous volatile fractions present in the
atmosphere or contamination from the handling of the sampling containers.
• Frequency: 1 blank/day/matrix or 1 blank/20 samples/matrix, whichever is
more frequent.

25. 25
3.3 Rinsate/Equipment Blank
• Equipment Blank results include total field and laboratory
sources of contamination.
• A sample of analyte free water poured over or through
decontaminated field sampling equipment prior to the
collection of environmental samples. Purpose: Assess the
adequacy of the decontamination process. Assess
contamination from the total sampling, sample preparation
and measurement process, when decontaminated sampling
equipment is used to collect samples.
• Frequency: 1 blank/day/matrix or 1 blank/20
samples/matrix, whichever is more frequent.
Nice logo

26. 26
3.4 The Initial Calibration Blank (ICB), (CCB)
Instrument Blank , Reagent blank, Calibration Blank, Standard blank.
• CCB Checks calibration validity After calibration, after <IDL Blank
every 10 analyses and at the end of analyses
• CCB is the same as the ICB but analyzed after each CCV.
• If the CCB is greater than three times the IDL, then the ten previous
samples must be reanalyzed for the failed analyte(s).
• However, if any of the ten previous samples are greater than ten
times the failed CCB, then these sample(s) do not have to be
reanalyzed.

27. 27
3.5 Laboratory Fortified Blank (LFB)
• Fortified method blank (FMB) - was fortified (spiked) with analyte(s) before digestion.
• The FMB is used to determine if the fortification and analysis methodology is in control.
• LFB Laboratory Fortified Blank Checks the recovery of analytes by spiking a known quantity
into a blank 1 per batch of samples 85-115% recovery or within ± 3 standard deviations of
the mean recovery :
Where:
R = percent recovery
LFB = laboratory fortified blank
LRB = laboratory reagent blank
s = concentration equivalent of analyte added to fortify the LBR solution

28. 28
4. Interference Chick Sample (ICS), (SIC)
• Spectral interference check (SIC) solutions (containing
similar concentrations of the major components in the
samples, e.g., ≥10 mg/L) can serve to verify the absence of
effects at the wavelengths selected.
• These data must be kept on file with the sample analysis
data.
• If the SIC solution (Interference Chick Sample ICS) confirms
an operative interference that is ≥10% of the analyte
concentration, the analyte must be determined using a
wavelength and background correction location free of the
interference or by another approved test procedure.
• Any analyte(s) that falls outside the error window of 10%
must be reanalyzed.

29. 29
5. Quality Control Sample (QCS), (LCS),(CCV)
• Quality control sample (QCS) on a quarterly basis to verify the calibration
standards and acceptable instrument performance.
• To verify the calibration standards the determined mean concentrations from
three analyses of the QCS must be within ±5% of the stated values.
• Percent recovery (%R) must be within 75-125% and calculated as: where:
LCS = LCS result, :g/L or mg/kg
B = Method blank result, :g/L or mg/kg
SA = Spike added, :g/L or mg/kg
• Aqueous and solid LCSs must be obtained from an independent source, and
must be prepared with each analytical batch of samples

30. 30
• Laboratory duplicates measure laboratory precision.
• The analytical results for laboratory duplicates are reported as the RPD (The Relative
Percent Difference) between the sample and duplicate results.
where: S = %R for matrix spike sample D = %R for matrix spike duplicate sample
• Laboratory duplicates are replicate samples and are prepared by taking two aliquots
from one sample container.
• Duplicate results are only used to determine precision and not compliance with a
standard and/or criteria.
6. Duplicate Sample Checks

31. 31
7. Matrix Spike/Matrix Spike Duplicate
At least one MS and one MSD sample must be digested with every 10 samples of the
same matrix, or with each batch type to verify the accuracy of the method.
calculate the Recoveries .
The Relative Percent Difference (RPD) of MS/MSD samples must be within ±20%.
where: SSR = Spiked sample result SR = Sample result SA = Spike added
A separate MS/MSD (matrix spike/matrix spike duplicate) must be prepared for
waters, soils, and extracts.
The relative percent difference (RPD) of the MSD must fall within 20% error and the
spike recovery must be within 25% error.

32. 32
8.1 Serial Dilution
• A sample (typically the sample chosen for the MS/MSD) from each project in an analytical
batch is analyzed at a 5x dilution in conjunction with the samples.
• The concentration in the undiluted sample must be greater than or equal to 50x the IDL to
obtain a meaningful comparison.
• The results of the serial dilution are multiplied by the dilution factor and compared to the
original determination (undiluted sample).
• Agreement within + 10% between the concentrations for the undiluted sample and the
diluted sample indicates the absence of matrix interferences for undiluted samples
meeting the 50x IDL criteria.
• If the concentration of all analytes in all samples is less than 50x the IDL, serial dilution is
not performed.
• Samples may also be successively diluted and analyzed to eliminate interferences. These
samples will be identified as dilution samples and not as serial dilutions.

33. 33
Dilution Test
• Dilution test: If the analyte concentration is sufficiently
high (minimally, a factor of 50 above the instrument
detection limit in the original solution but <90% of the
linear limit), an analysis of a 1+4 dilution should agree
(after correction for the fivefold dilution) within ±10%
of the original determination.
• If not, a chemical or physical interference effect should
be suspected and the associated data flagged
accordingly.
• The method of standard additions or the use of an
internal-standard element may provide more accurate
data for samples failing this test.

34. 34
8.2 Dilution Analysis
• If the concentration of any analyte in any sample exceeds the linear range, the
sample must be diluted and re-analyzed.
• An appropriate dilution or series of dilutions (for example, 5x, 10x, 20x) may be
required depending on the concentration in the undiluted sample.
• Results are reported from the lowest dilution that falls within the linear range.
• If chemical/physical matrix effects are suspected or for analytes that saturate the
detector, samples must be diluted and re-analyzed.
• An appropriate dilution or series of dilutions may be required depending on the
concentrations in the undiluted sample.
• Comparisons are first made with respect to the undiluted sample and then, within
the series.
• Based on the analyst's professional judgment, results are reported from the diluted
sample that has the smallest dilution factor and indicates the absence of
interferences.
• An optional approach to determine if chemical/physical matrix effects are present is
to use post digestion spike (PDS) analysis.

35. 35
9. QC & QA
9.1 Initial Calibration Verification
9.2 Interference Check Standards
9.3 Continuing Calibration Verification
9.4 Initial/Continuing Calibration Blanks
9.5 Method Blank
9.6 Laboratory Control Sample
9.7 Matrix Spike/Matrix Spike Duplicate
9.8 Linear Analytical Range
9.9 Serial Dilution
9.10 Dilution Analysis
9.11 Initial Demonstration of Capability
9.12 Method Detection Limit Studies
9.13 Reporting Limit Standards*
9.14 Instrument Detection Limits
9.15 System Troubleshooting
9.16 Nonconformance Memo

36. 36
QC &QA
The Best Way To Address QA & QC Is By Preparing A LABORATORY
QUALITY MANUAL (LQM) In Line With
ISO/IEC 17025
General Requirements For The Competence Of Testing And
Calibration Laboratories

37. 37
Quality Control
Check Name Check Code Purpose Frequency Limits
QCS Quality Control
Standard
Checks the accuracy of the
calibration with a second source
standard
Post Calibration 95-105% recovery
SIC Spectral
Interference
Check Solution(s)
Checks for the presence of spectral
interference and the effectiveness
of inter-element corrections
Periodically No specific requirements
IPC Instrument
Performance
Check
A continuing check of accuracy and
drift normally done by re-
measuring a standard as a sample
Every 10
analyses and at
the end of run
95-105% recovery immediately
following calibration; 90-110%
recovery thereafter
Blank Check Blank A continuing check of the blank
level by re-measuring the
calibration blank as a sample
Every 10
analyses and at
the end of run
< IDL
LRB Laboratory
Reagent Blank
Checks the laboratory reagents
and sample preparation process
for contamination
1 per batch of 20
or fewer samples
< 2.2 x MDL
LFB Laboratory
Fortified Blank
Checks the recovery of analytes by
spiking a known quantity into a
blank
1 per batch of
samples
85-115% recovery or within ± 3
standard deviations of the mean
recovery
LFM Laboratory
Fortified Matrix
Checks the recovery of analytes in
a matrix by spiking a known
quantity into a batch sample
1 in 10 samples 85-115% recovery or within ± 3
standard deviations of the mean
recovery

38. 38
Sequence of analysis
1. Calibrate the ICP using a blank and the working calibration standard.
2. Immediately following calibration, analyze the ICV standard. The percent recovery
must be within ±10%.
3. Immediately following the ICV, analyze the ICB. The concentration must be less than
(<) the reporting limit (RL) for each element.
4. Analyze the appropriate RL standard (RLW or RLS), ICSA, ICSAB, continuing
calibration verification (CCV), and continuing calibration blank (CCB) standards.
5. Analyze the method blank, LCS, and samples.
6. A CCV/CCB must be run every 10 samples. At the end of the analytical sequence, a
ENDCCV/CCB must be analyzed.
7. The ICSA and ICSAB must be run at the beginning of the sequence and when the
sequence exceeds an 8-hour shift.
8. If the concentration found is greater than the linear analytical range ,the sample
must be diluted with 10% HNO3 and reanalyzed .
9. To verify the absence of interference, follow the serial dilution analysis procedure.

39. 39
An Example Analytical Sequence for ICP-AES
No. Example (1) QC error limits Example (2)
1 Calibration blank 1 SO
2 Calibration standard 2 S
3 ICV standard ± 10% 3 S
4 ICV blank <3 × IDL 4 S
5 ICS[A] ± 20% 5 S
6 MB <3× IDL 6 S
7 Sample 1 7 ICV
8 Sample 1 C MS ± 25% 8 ICB
9 Sample 1 C MSD ± 20% RPD 9 ICSA
10 Sample 2 10 ICSAB
11 Sample 3 11 CCV
12 Sample 4 12 CCB
13 Sample 5 13 Samples ( 10 -20)
14 Sample 6 14 CCV
15 CCV ± 10% 15 CCB
16 CCB <3 × IDL 16 Samples ( 10 -20)
17 Sample 7 17 CCV
18 Sample 8 18 CCB etc.

40. 1. Liner Dynamic Range “LDR”
2. Accuracy “QCS”
3. Detection Limit “IDL & MDL”
4. Interference “SIC”

41. 41
1. Linear Dynamic Range (LDR)
• The LDR should be determined by analyzing
succeeding 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.
• Samples greater than 90% of upper LDR limit
must be diluted and reanalyzed.
• LAR standards must be analyzed and reported on
a quarterly basis.

42. 42
2. Accuracy (QCS), (LCS),(CCV)
• Quality control sample (QCS) on a quarterly basis to verify the calibration
standards and acceptable instrument performance.
• To verify the calibration standards the determined mean concentrations from
three analyses of the QCS must be within ±5% of the stated values.
• Percent recovery (%R) must be within 75-125% and calculated as: where:
LCS = LCS result, :g/L or mg/kg
B = Method blank result, :g/L or mg/kg
SA = Spike added, :g/L or mg/kg
• Aqueous and solid LCSs must be obtained from an independent source, and
must be prepared with each analytical batch of samples

43. 43
3. Method Detection Limit (MDL)
• MDLs must be established for all wavelengths utilized, using reagent water (blank)
fortified at a concentration of two to three times the estimated instrument
detection limit.
• To determine MDL values, take seven replicate aliquots of the fortified reagent water
and process through the entire analytical method.
• Calculate the MDL as follows:
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
• (MDL) studies will be run on an annual basis and when a new operator begins work
to verify the minimum concentration that can be measured and reported with 99%
confidence.

44. 44
IDL, LOD, ASDL
Three types of detection limits are discussed - method limit of detection (LOD),
instrument detection limit (IDL), and analytical solution detection limit (ASDL).
The terms LOD and IDL are relevant to all methods, although the exact procedure for
calculating them differs. In contrast, ASDL is relevant for only some methods.
IDL is the lowest level that an instrument's detector can measure and ASDL is the lowest
level that can be detected in a test solution obtained after a test portion is digested.
Whereas IDL represents an ideal case (e.g., without matrix effect), LOD and ASDL apply
to a real-world sample.
where: n = number of blank measurements
(standard blanks for IDL and method blanks for ASDL)
t95 = one-sided Student’s t at 95% confidence level
s = standard deviation of blank measurements (3 significant digits)

45. 45
4. Interference Chick Sample (ICS), (SIC)
• Spectral interference check (SIC) solutions (containing
similar concentrations of the major components in the
samples, e.g., ≥10 mg/L) can serve to verify the absence of
effects at the wavelengths selected.
• These data must be kept on file with the sample analysis
data.
• If the SIC solution (Interference Chick Sample ICS) confirms
an operative interference that is ≥10% of the analyte
concentration, the analyte must be determined using a
wavelength and background correction location free of the
interference or by another approved test procedure.
• Any analyte(s) that falls outside the error window of 10%
must be reanalyzed.

46. 46
Physical Interferences
A characteristic difference between sample and standard
which affects sample introduction or nebulization
1. Viscosity
2. High Dissolved Solids (density)
3. Acid type or concentration
4. Surface tension
5. Organic solvents
Physical interfaces can be easily over come by matrix matching of the standards, and/or
use of a an internal standard

47. Check Protocols
1. QC
2. Recovery
3. Limit
4. Duplicate
5. IECs
6. Internal Standard

48. 48
• These protocols are used to set limits for various
activities, indicate the acceptable range for a QC
sample, and to indicate the limits for a warning or
failure.
• Standard Normalization type;
Only a QC check can initiate actions to be taken
such as, Re-calibrate, Repeat Sample Analyses,
etc. Any other check type, such as Recovery, Limit
check or Duplicate can only pass or fail.
Check Protocols

49. 49
• The QC sample elements concentrations should
with a high degree of accuracy, but it need not
be a standard.
• Slope - Will adjust the calibration curve re-
slope value as displayed in Method, Element,
Fit, so that the instrument response for the
highlighted QC sample corresponds to its known
concentration.
• Offset - Will adjust the Y-intercept so that the
instrument response for the highlighted QC
sample corresponds to its known concentration.
1. QC Checks

50. 50
If QC Actions were defined in the method, the
following options can be selected:
• Normalize Slope,
• Normalize Y-intercept,
• Normalize From QC table,
• Matrix Normalize From QC table,
• Autocalc IECs,
• Calibrate QC failed,
• Standardize QC failed.
QC Actions

51. 51
• An unknown sample is spiked (an additional
concentration of the element(s) of interest is
added and then reanalyzed).
• The analytical result should be the original
result plus the concentration of the added
spike (the spike is then said to be "100 %
recovered").
• To use the recovery function, you must first
analyze an unknown, then select Results/Run
Recovery and select the appropriate recovery
check table from the dropdown menu.
2. Recovery Checks

52. 52
Spike
Check Type, Recovery
• When Recovery is selected on the New Check
Table dialog box, the Default Check Range fields
are Low Failure, Low Warning, Spike, High
Warning and High Failure.
• The range units are the same as for a QC check.
• Selection of parameters in the Checks dialog box
is identical to that for QC check, except for the
Std Normalization type.
• The Spike value is the concentration of the
element(s) of interest that was added to the
sample.

53. 53
• These are applied to unknown
samples.
• A limit check table contains a list of
elements along with a high and low
acceptable result for each.
• A result which falls above its high limit
check, or below its low limit check will
be flagged.
3. Limit Checks

54. 54
• Laboratory duplicates measure laboratory precision.
• The analytical results for laboratory duplicates are
reported as the RPD (The Relative Percent Difference)
between the sample and duplicate results.
• Laboratory duplicates are replicate samples and are
prepared by taking two aliquots from one sample
container.
• Duplicate results are only used to determine precision
and not compliance with a standard and/or criteria.
4. Duplicate Checks

55. 55
• This is used to determine if two (or more)
analyses of a given sample provide the
same analytical result within a user-
specified tolerance.
• To run a Duplicate:
1. Analyze a sample in the normal fashion.
2. Select Run Duplicate on the Results
menu to present the Run Duplicate dialog
box.
Run Duplicate

56. 56
5. Interfering Element Correction (IECs)
• Inter-element interferences occur when elements in
the sample emit radiation at wavelengths so close to
that of the analyte that they contribute to the
intensity of the light striking the analyte pixels.
• These are direct spectral overlaps, and the IEC
correction attempts to correct for this overlap (and
subsequent contaminated data) by applying a
ratioed correction factor to all samples.
• Requires the wavelengths used for analysis to be
checked for the presence of interfering elements.
• For this purpose, a series of Spectral Interference
Check (SIC) solutions are used

57. 57
6. Internal Standard
Internal standard can help compensate for sample viscosity effects and plasma loading and can
improve the accuracy and precision of analytical results in emission spectrometry.
1. Choose an element that is not present in your samples or matrix.
2. Then add it in equal concentration to all samples and standards .
3. Internal standard is introduced at a constant rate, its signal should remain constant.
4. The analytical lines referenced to an internal standard report a corrected concentration
value based on the ratio of analyte to internal standard intensities.
5. Software determining concentrations of analytes are based on Intensity Ratio.
6. This value is defined as the background corrected intensity signal of the analyte line (Ia)
divided by an internal standard value (Iis).
IR = I[a]/I[is]

58. 58
• Sequence Automation refers to the addition of a series
of steps before, during or after an analysis run.
• Initial Actions Operations which qualify the sample
preparation, standards, method and instrument may
be required for every sequence of samples run.
• Continuing actions operations such as blanks,
calibration checks, and recoveries and need to be run
frequently throughout the entire sequence of samples
to ensure the instrument is operating constantly.
• End Actions These are identical to the Initial Actions
field and the only operations that can be performed
are QC methods.
Sequence Automation