<< Click to Display Table of Contents >> Navigation:  DQM > DQM Checks > Blank Contamination Checks > Lab Blank Contamination Check

•Check

•Parameters

•Rules

•Exceptions

•Errors

 

The DQM Check for Lab Blank Contamination identifies detected concentrations of target analytes in laboratory blanks. If a detected analyte in a laboratory blank is also contained in an associated sample at a similar level as that in the blank, DQM will qualify the associated sample result.

 

Check

 

The check name is EarthSoft.DQM.LabBlankContamination.

 

Parameters

 

This check uses four Global Parameters:

1.reportable_result – DT_RESULT.REPORTABLE_RESULT values to include in DQM datasets

2.result_type_code – DT_RESULT.RESULT_TYPE_CODE to include in DQM datasets

3.test_type_batch – AT_TEST_BATCH_ASSIGN.TEST_BATCH_TYPE to include in DQM dataset

4.nondetect_detection_limit – Identifies which detection limit column from DT_RESULT to populate DT_RESULT.RESULT_VALUE

 

 

This check uses the following seven check parameters (listed below). None of these parameters allow for input of method-specific PARAM_VALUEs. However, the common_lab_multiplier allows analyte-specific PARAM_VALUEs for each CAS_RN. Additionally, matrix-specific AND analyte- or method-specific multipliers can be used by populating RT_DQM_CONTROL_LIMITS.BLANK_MULTIPLIER. See below for additional information on the order of what {MULTIPLIER} is used.

1.LabBlankSampleType – The SAMPLE_TYPE_CODE used for laboratory blanks; defaults to "LB".

2.MethodBlankSampleType – The SAMPLE_TYPE_CODE used for laboratory method blanks; defaults to "MB".

3.Multiplier – Used by DQM to determine if a result can be qualified as non-detect; defaults to 1. Must be an integer.

4.Common_lab_multiplier – Used by DQM to determine if a result identified as a common laboratory contaminant can be qualified as non-detect; depends on CAS_RN field being populated and defaults to 2. Must be an integer.

5.Flag_blank – If TRUE, the laboratory blanks are also qualified; defaults to "TRUE".

6.Normal_sample_types – The SAMPLE_TYPE_CODEs used for standard association of laboratory blanks; defaults to “N”.

7.result_type_code – the result type(s) of the results to be included in this check. The default value is “TRG”.

 

 

Rules

 

There are six rules available:

1.BLANK CONTAMINATION < QL – Contamination detected in the Blank less than the Quantitation/Detection Limit.

2.BLANK CONTAMINATION >= QL – Contamination detected in the Blank greater than or equal to the Quantitation/Detection Limit.

3.RESULT/DF < QL – Associated Result / Dilution Factor < Quantitation/Detection Limit.

4.RESULT/DF >= QL OR >= BLANK * {MULTIPLIER} – For Blank Conc < QL, Associated Result / Dilution Factor >= Quantitation/Detection Limit OR >= multiplier * concentration detected in the associated blank.

5.RESULT/DF >= QL & < BLANK * {MULTIPLIER} – For Blank Conc >= QL, Associated Result / Dilution Factor >= Quantitation/Detection Limit AND < multiplier * concentration detected in the associated blank.

6.RESULT/DF >= BLANK * {MULTIPLIER} – For Blank Conc >= QL, Associated Result / Dilution Factor >= multiplier * concentration detected in the associated blank.

 

There were 3 different blank rules available in the 7.21.1 Build and earlier builds (BLANK CONTAMINATION, RESULT > BLANK * MULTIPLIER, RESULT < BLANK * MULTIPLIER). If those 3 rules exist in a DQM QAPP, along with the 6 rules listed above, then only the 6 above rules (available starting in the 7.21.2 Build) will be used by DQM. For the 3 rules available in the 7.21.1 Build (and earlier builds) to be used by DQM, then only those 3 rules should be included in the DQM QAPP.

 

Associated results are found by:

1.Matching results (with detected concentrations only) by Method, Fraction, CAS_RN and TEST_BATCH_ID. If matching samples are found, the process stops.

2.If no matching results are found in Step 1, results (with detected concentrations only) are matched by Method, Fraction, CAS_RN and LAB_SDG.

 

 

Use of Reason Codes with the rules is discussed here.

 

Exceptions

 

For Lab Blanks:

•Review blanks if Flag_blank = TRUE.

•Review results with DT_SAMPLE.SAMPLE_TYPE_CODE = LabBlankSampleType and MethodBlankSampleType.

•Qualify a result in a lab blank if REPORTABLE_RESULT = Y and DETECT_FLAG = Yes according to the following:

1.If BLANK CONTAMINATION < QL – The APPLY_REMARK is “Contamination detected in the Blank less than the Quantitation/Detection Limit.”
An example DQM_REMARK for this exception is: “[0.5 < 1] Blank result < Quantitation/Detection limit in this blank.”

2.BLANK CONTAMINATION >= QL – The APPLY_REMARK is “Contamination detected in the Blank greater than or equal to the Quantitation/Detection Limit.”
An example DQM_REMARK for this exception is: “[8 >= 1] Blank result >= Quantitation/Detection limit in this blank.”

 

 

For Associated Samples:

•Review results with DT_SAMPLE.SAMPLE_TYPE_CODE = Normal_sample_types.

•{MULTIPLIER} = if an analyte-specific match is found for common_lab_multiplier, then that value is used. If no match is found, the check looks for matches in RT_DQM_CONTROL_LIMITS and uses the BLANK_MULTIPLIER value. Using a multiplier from RT_DQM_CONTROL_LIMITS is discussed in more detail here. If no match is found for either, DQM defaults to the Multiplier parameter value.

•Qualify a result in an associated sample if REPORTABLE_RESULT = Y and DETECT_FLAG = Yes according to the following:

1.RESULT/DF < QL – The APPLY_REMARK is “Associated Result from: Associated Result / Dilution Factor < Quantitation/Detection Limit.”
An example DQM_REMARK for this exception is: “[0.3 / 1 < 1] Sample result / dilution factor < Quantitation/Detection limit in this associated blank: (sys_sample_code:AQ_SAMPLE1_RC_TB, analytic_method:SW6010, cas_rn:7440-28-0).”

2.RESULT/DF >= QL OR >= BLANK * {MULTIPLIER} – The APPLY_REMARK is “Associated Result from: For Blank Conc < QL, Associated Result / Dilution Factor >= Quantitation/Detection Limit OR >=concentration detected in the associated blank.”
An example DQM_REMARK for this exception is: “[5 / 1 >= 1 * 0.5] Sample result / dilution factor >= multiplier * concentration detected in this associated blank: (sys_sample_code:AQ_SAMPLE1_RC_TB, analytic_method:SW6010, cas_rn:7440-28-0)”

3.RESULT/DF >= QL & < BLANK * {MULTIPLIER} – The APPLY_REMARK is  “Associated Result from: For Blank Conc >= QL, Associated Result / Dilution Factor >= Quantitation/Detection Limit AND < multiplier * concentration detected in the associated blank.
An example DQM_REMARK for this exception is: “[10 / 1 >= 1] AND [10 / 1 < 2 * 8] Sample result / dilution factor >= Quantitation/Detection limit AND < multiplier * concentration detected in this associated blank:(sys_sample_code:AQ_SAMPLE1_RC_TB, analytic_method:SW6010, cas_rn:7782-49-2).”

4.RESULT/DF >= BLANK * {MULTIPLIER} – The APPLY_REMARK is “Associated Result from: For Blank Conc >= QL, Associated Result / Dilution Factor >= multiplier * concentration detected in the associated blank.
An example DQM_REMARK for this exception is: “[10 / 1 >= 1 * 8] Sample result / dilution factor >= multiplier * concentration detected in this associated blank: (sys_sample_code:AQ_SAMPLE1_RC_TB, analytic_method:SW6010, cas_rn:7782-49-2).”

•If the Associated Sample's Reason Code ends with a "+" then the parent QA Sample Exception's Reason Code will be appended to the Associated Sample's Reason Code using an underscore and the "+" removed. (For example: when the rt_dqm_rule.reason_code = "LBA1+" and the QA Sample Reason Code is "LBH", then the associated result reason code becomes "LBA1_LBH".)

•If the Associated Sample's Reason Code in rt_dqm_rule.reason_code = "+", then the QA Sample's Reason Code is used instead.

 

Errors

 

In the Errors Tab of the DQM Event Review Form, these errors may be listed:

1.“Associated result has units ({0}) that do not convert to units of blank result ({1}).”
This check includes an internal unit conversion function which includes the below conversions. This allows blanks with liquid  units to be compared to results for soil samples. This error message occurs if the units differ and none of the below conversion factors apply.

▪ug/L to mg/kg

▪ug/L to ug/kg

▪mg/L to mg/kg

▪mg/L to ug/kg

▪Any combination of units found in RT_UNIT_CONVERSION_FACTOR will also be used.

For this check to work, a record must be added to RT_UNIT_CONVERSION_FACTOR for that combination.

2."The Quantitation/Detection Limit is missing for (sys_sample_code:{0}, analytic_method:{1}, cas_rn:{2})"
When this error is present, this check will be skipped for this result and the associated results.

3."Blank Result's Detect Flag = Y and Result_Numeric is NULL or Non-Numeric for (sys_sample_code:{0}, analytic_method:{1}, cas_rn:{2})"
When this error is present, this check will be skipped for this result and the associated results.

4."Associated Result's Detect Flag = Y and Result_Numeric is NULL or Non-Numeric for (sys_sample_code:{0}, analytic_method:{1}, cas_rn:{2})"
When this error is present, this check will be skipped for this individual associated result.

5."The DILUTION_FACTOR column is NULL or not numeric at (sys_sample_code:{0}, analytic_method:{1}, cas_rn:{2})"
When this error is present, this check will be skipped for this individual associated result.