DQM Check for Lab Blank Contamination

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DQM Check for Lab Blank Contamination

The check name is EarthSoft.DQM.LabBlankContamination. This check uses the following parameters:

LabBlankSampleType

MethodBlankSampleType

Multiplier – used in test to determine if result can be qualified as non-detect - defaults to 5 if no value supplied.

Common_lab_multiplier – depends on CAS_RN – default multiplier is used if no value supplied.

Flag_blank – if TRUE, the blanks are also qualified – defaults to TRUE.

 

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.

 

Note: To use the TEST_BATCH_ID, it must be added to DT_TEST_BATCH and then the TEST_ID of the blank sample, and all of the associated TEST_IDs are added with their TEST_BATCH_ID and TEST_BATCH_TYPE to AT_TEST_BATCH_ASSIGN (usually done by EDP format).

 

There are three rules:

1.BLANK CONTAMINATION = Qualify the result in the blank sample if a concentration is detected and the FLAG_BLANK parameter = TRUE.

2.RESULT > BLANK * MULTIPLIER = Qualify an associated result if sample result > multiplier * concentration detected in the associated blank.

3.RESULT < BLANK * MULTIPLIER = Qualify an associated result if sample result < multiplier * concentration detected in the associated blank. Assuming the qualifier for this rule = “U”, then this will indicate the result is non-detect. When Completing an Event and saving qualifiers, there is also an option to set DETECTED_YN to "N" for all results with a "U" qualifier.

 

Unit Conversions

 

This check includes an internal unit conversion function, which allows blanks with units for liquids to be compared to results for soil samples. This internal function includes:

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.

 

The following error occurs if the units differ and none of the above conversion factors apply:

 

Associated result (. . . .  has units (. . . .) that do not convert to units of blank result (. . . .).  

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