<< Click to Display Table of Contents >> DQM Control Limits 
Copyright © 2019 EarthSoft, Inc • Modified: 18 Feb 2019 

The RT_DQM_CONTROL_LIMITS table defines QAPPspecific control limits for the following DQM Checks:
•Spike Recovery
•Surrogate Recovery
•Relative Percent Difference (RPD)
When values for particular control limits are supplied in this table, they are used in the relevant DQM Check instead of the control limits supplied by the lab in the DT_RESULTS_QC table.
If control limit values are not found in either table, then an error is written to the Error tab in the Process Event Form.
For each DQM QAPP, the control limits can be set for general application to MATRIX_CODE, which is a required field. This MATRIX_CODE is matched to DT_SAMPLE.MATRIX_CODE to find the applicable control limits.
Control limits can be set for more specific combinations by including values in the ANALYTIC_METHOD, METHOD_ANALYTE_GROUP_CODE and/or CAS_RN fields.
The process for finding a matching record in RT_DQM_CONTROL_LIMITS is as follows:
1.For Events Created without Specifying a Method Analyte Group (MAG) – Look for a record with METHOD_ANALYTE_GROUP_CODE = NULL and
a.A matching MATRIX_CODE, ANALYTIC_METHOD, and CAS_RN.
b.If not found, then a matching MATRIX_CODE and CAS_RN.
c.If not found, then a matching MATRIX_CODE and ANALYTIC_METHOD.
d.If not found, then a matching MATRIX_CODE.
e.If not found, then look in DT_RESULTS_QC and/or RT_HOLDING_TIME for control limits.
2.For Events Created with a Specific MAG – Look for a record with:
a.A matching MATRIX_CODE, ANALYTIC_METHOD, METHOD_ANALYTE_GROUP_CODE and CAS_RN.
b.If not found, then a matching MATRIX_CODE, METHOD_ANALYTE_GROUP_CODE and CAS_RN.
c.If not found, then a matching MATRIX_CODE, ANALYTIC_METHOD and CAS_RN.
d.If not found, then a matching MATRIX_CODE and CAS_RN.
e.If not found, then a matching MATRIX_CODE, METHOD_ANALYTE_GROUP_CODE and ANALYTIC_METHOD.
f.If not found, then a matching MATRIX_CODE and METHOD_ANALYTE_GROUP_CODE.
g.If not found, then a matching MATRIX_CODE and ANALYTIC_METHOD.
h.v not found, then a matching MATRIX_CODE.
i.If not found, then look in DT_RESULTS_QC and/or RT_HOLDING_TIME for control limits.
Note: If a more specific combination of ANALYTIC_METHOD, etc. is added to RT_DQM_CONTROL_LIMITS, be sure to specify all of the control limits being used, even if they are the same as those listed in less specific combinations. For example, to change the value for the matrix spike columns in the more specific case, the lab control spike and surrogate column data must still be included, even if it is the same as the less specific case. 
Use the following columns in the RT_DQM_CONTROL_LIMITS table to define the acceptable spike recovery range, where "lcl" denotes the lower control limit and "ucl" denotes the upper control limit.
Lab Control Spike (LCS) Samples
RT_DQM_CONTROL_LIMITS (if populated) 
DT_RESULT_QC (if RT table not populated) 

lcs_recovery_lcl 
qc_spike_lcl 
lcs_recovery_ucl 
qc_spike_ucl 
Matrix Spike (MS) Samples
RT_DQM_CONTROL_LIMITS (if populated) 
DT_RESULT_QC (if RT table not populated) 

ms_recovery_lcl 
qc_spike_lcl 
ms_recovery_ucl 
qc_spike_ucl 
Use the following columns in the RT_DQM_CONTROL_LIMITS table to define the acceptable surrogate recovery range, where “lower_cutoff” denotes the lower rejection limit, "lcl" denotes the lower control limit, and "ucl" denotes the upper control limit.
RT_DQM_CONTROL_LIMITS (if populated) 
DT_RESULT_QC (if RT table not populated) 

surr_rec_lower_cutoff 
rt_holding_time.lower_surrogate_cutoff 
surr_recovery_lcl 
qc_spike_lcl 
surr_recovery_ucl 
qc_spike_ucl 
To define control limits for individual surrogate recoveries, create a record for each surrogate (with the QAPP code, matrix, and analytic method populated) and populate:
•RESULT_TYPE_CODE = ‘SUR’ and
•CAS_RN = the surrogate CAS_RN.
Surrogate Recovery Associated Results
The Surrogate Recovery Check adds a qualifier to Associated Results from the same DT_TEST.TEST_ID. For some surrogates, such as acid and base surrogates for analytic method SW8270, a more specific list of associated results is desired. To create a surrogatespecific list of CAS_RNs to associate, enter the following into the RT_DQM_CONTROL_LIMITS table for each analyte to be associated, repeated for each surrogate:
•DQM_QAPP_CODE = 'QAPP_SURR_ASSO_CAS_RN'
oRather than requiring this list to be repeated for each QAPP, DQM uses a single DQM_QAPP_CODE just for these lists.
•MATRIX_CODE = a valid MATRIX_CODE from RT_MATRIX
oThis column is required as part of the primary key for this table, but the matrix code is NOT used to match Associated Results from this list.
•ANALYTIC_METHOD = NULL (or the analytic method for the surrogate)
oThis column may be populated for informational purposes, but the analytic method is NOT used to match Associated Results from this list.
•RESULT_TYPE_CODE = NULL (or the result type code for a standard result in the current database, such as 'TRG')
oThis column may be populated for informational purposes, but the result type code is NOT used to match Associated Results from this list.
•CAS_RN = the CAS_RN of analyte to be associated
o If there are multiple surrogates, these records need to be repeated for each surrogate.
•SURR_ASSO_CAS_RN = the CAS_RN of the surrogate
For the Relative Percent Difference (RPD) check, use the following fields to define different RPD control limits for Lab Control Spike Duplicates, Matrix Spike Duplicates, and Lab Duplicates.
RT_DQM_CONTROL_LIMITS (if populated) 
DT_RESULT_QC (if RT table not populated) 

lcs_dup_rpd_cl 
qc_rpd_cl 
ms_dup_rpd_cl 
qc_rpd_cl 
lab_dup_rpd_cl 
qc_rpd_cl 
The Field RPD check already has the following parameters for RPD control limits:
•rpd_control_limit_soil
•rpd_control_limit_water
•rpd_control_limit_other
To provide a different control limit for a method analyte group, ANALYTIC_METHOD, or CAS_RN, populate the FIELD_DUP_RPD_CL column. This will override the Field RPD Check control limit parameter for the given matrix.
Each check for Blank Contamination already has the multiplier parameter to control how the check marks a result using the following two rules:
1.RESULT > BLANK * MULTIPLIER = Qualify an associated result if sample result > multiplier * concentration detected in the associated blank.
2.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 nondetect.
To provide a different multiplier for a method analyte group, ANALYTIC_METHOD or CAS_RN, populate the BLANK_MULTIPLIER column. This will override the Blank Contamination Check multiplier parameter.
The RT_HOLDING_TIME table defines QAPPspecific control limits for the DQM Holding Time Check. The DQM_QAPP_CODE, ANALYTIC_METHOD, MEDIUM_CODE, HT_UNIT, and CALCULATION_UNIT are required.
The Holding Times Check will only be applied to the time frames that have a value in the respective column.
•Collect date is determined by DT_SAMPLE.SAMPLE_DATE.
•Prep date is determined by DT_TEST.PREP_DATE.
•Leachate date is determined by DT_TEST.LEACHATE_DATE.
•Analysis date is determined by DT_TEST.ANALYSIS_DATE.