USEPA Validation Study Report for Hach Method 8026 Copper

Spectrophotometric Measurement of Copper in Drinking Water

Submitted by:

Hach Company

5600 Lindbergh Drive

Loveland Colorado 80538

Cary Jackson 

and

Luke Johnson

November 2015
Hach Company Validation Study Report

Measurement of Copper in Water, Method 8026

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Background

Purpose of Study

The purpose of this study is to evaluate the proposed Hach Company Measurement of Copper

(Cu) in Water, Method 8026, against USEPA Reference Copper Method EPA 200.7 for approval 

and use in USEPA regulatory water compliance and reporting programs.

Method Summary

The Hach Cu chemistry uses 2,2’-biquinoline-4,4’-dicarboxylic acid (bicinchoninic acid) for color 

development. Cuprous copper complexes with bicinchoninic acid to form a purple colored 

complex. The intensity of the color of this complex is proportional to the concentration of 

copper in the sample. Cupric copper is chemically reduced. Metal and hardness interferences 

are overcome through the addition of a chelating agent. Test results are measured at 560 nm. 

Method Justification

EPA reference method EPA 200.7 requires an expensive analytical instrument for the 

measurement of copper. Proposed Hach Method 8026 for the Spectrometric Measurement of 

Copper uses a simple and inexpensive chemical analysis to measure copper. 

Scope of Method

Method 8026 is applicable for use in drinking water. 

Study Design and Objectives

The design and objectives of this validation study are detailed in the Validation Study Plan1

appended to this report.

Study Implementation

Study Sponsor

The organizational sponsor responsible for managing this study is Hach Company.

Study Participants

 

1 Hach Validation Study Plan, March 2015
Hach Company Validation Study Report

Measurement of Copper in Water, Method 8026

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The participants, laboratories, and test matrices were selected from geographically diverse 

regions of the United States and are listed in the following table.

Treated Drinking 

Water Matrix 

Facility

Laboratory Source of Treated 

Test Water

Loveland, Colorado Hach Company, TestAmerica-Pittsburgh Surface Water

Cedar Falls, Iowa Test America-Cedar Falls Surface Water

Brighton, Colorado ALS Environmental Ground Water

Sample Collection and Distribution

Matrix samples for this validation study were collected, preserved, and stored per EPA 200.7 

protocols.

Analysis Description

The description of the type and number of analyses are described in the Validation Study Plan 

appended to this report.

Data Reporting and Validation

Data Collection, Laboratory Submission, and Validation

For each laboratory performing analyses, results from each test measurement were read from a 

DR1900 or DR5000 spectrophotometer with built-in calibration, and manually transferred to an 

electronic spread sheet. Each laboratory then submitted the electronic spread sheet to the 

Hach Study Director for review and statistical evaluation. 

Results

Summary results of the validation study are listed in Tables 1-5. Initial demonstration of 

capability is demonstrated by accuracy (bias) and precision data which are generated 

throughout the calibration range and at the maximum contaminant level (MCL) in several

matrices. These data were collected at the Hach laboratory and are included in Table 1. The 

quantitation range and method reporting limits for this method are 0.1 – 5.00 mg/L Cu.
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Measurement of Copper in Water, Method 8026

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Table 1 – Initial Demonstration of Capability for Hach Method 8026

Parameter Concentration 

(mg/L)

LIS 250 mg/L CO3 250 mg/L CaCO3 2.5 mg/L TOC

Method Blank 0 0.01 0.02 0.01 0.01

LIS 250 mg/L CO3 250 mg/L CaCO3 2.5 mg/L TOC

0.5 6.0 2.7 2.7 4.0

1.3 5.4 3.6 1.0 0.8

5.0 3.5 2.8 1.9 1.8

LIS 250 mg/L CO3 250 mg/L CaCO3 2.5 mg/L TOC

0.5 1.9 1.1 1.1 1.9

1.3 0.0 0.4 0.4 0.8

5.0 0.8 0.9 0.7 1.0

Loveland DW Brighton DW Keokuk DW

Low 1.3 1.3 0.7

Mid 1.5 2.1 2.6

High 1.0 0.5 0.1

Loveland DW Brighton DW Keokuk DW

Low 2.0 1.1 1.1

Mid 0.7 0.4 1.1

High 0.0 0.8 0.3

Precision 

Average Percent Bias by Matrix

Average Percent Bias by Matrix

Accuracy (bias) 

Percent Relative Standard Deviation by Matrix

Average Percent Recovery by Matrix

Matrix Spike 

Accuracy (bias)

Percent Relative Standard Deviation by Matrix

Matrix Spike 

Precision
Hach Company Validation Study Report

Measurement of Copper in Water, Method 8026

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Table 2 – Loveland Colorado Tap Water Performance Results 

Method 

Detection 

Limit (mg/L)

Method 

Detection 

Limit (mg/L)

Low Ionic Strength 

Reagent Water 0.006 0.07

High Ionic Strength 

Reagent Water 0.007 0.05

Average 

Percent (%) 

Recovery

Percent Bias Standard 

Deviation

Average 

Percent (%) 

Recovery

Percent Bias Standard 

Deviation

Low Ionic Strength 

Reagent Water 104 3.9 0.3 97.3 2.8 1.3

High Ionic Strength 

Reagent Water 88.4 11.6 0.3 93.8 6.3 1.0

Average 

Percent (%) 

Recovery

Relative 

Percent 

Difference

Average 

Percent (%) 

Recovery

Relative 

Percent 

Difference

88.5 0.4 91.3 6.1

Matrix Spike Analysis Matrix Spike Analysis

Matrix

EPA 200.7 Hach Method 8026

Initial Precision and Recovery Initial Precision and Recovery

Loveland Treated 

Tap Water
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Measurement of Copper in Water, Method 8026

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Table 3 –Cedar Falls Tap Water Summary Results 

Method 

Detection 

Limit (mg/L)

Method 

Detection 

Limit (mg/L)

Low Ionic Strength 

Reagent Water 0.005 0.02

High Ionic Strength 

Reagent Water 0.006 0.02

Average 

Percent (%) 

Recovery

Percent Bias Standard 

Deviation

Average 

Percent (%) 

Recovery

Percent Bias Standard 

Deviation

Low Ionic Strength 

Reagent Water 95.0 5.0 1.08 99.4 0.6 1.1

High Ionic Strength 

Reagent Water 94.8 5.3 1.19 96.9 3.1 0.48

Average 

Percent (%) 

Recovery

Relative 

Percent 

Difference

Average 

Percent (%) 

Recovery

Relative 

Percent 

Difference

97.8 0.0 92.8 0.5

Matrix

EPA 200.7 Hach Method 8026

Initial Precision and Recovery Initial Precision and Recovery

Cedar Falls Treated 

Tap Water

Matrix Spike Analysis Matrix Spike Analysis
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Measurement of Copper in Water, Method 8026

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Table 4 – Brighton Colorado Drinking Water Plant Summary Results

Development of QC Acceptance Criteria

Quality control acceptance criteria for method detection limit (MDL), initial precision and 

recovery (IPR), and matrix spike recovery are described in Table 5. Calibration verification is 

demonstrated through the accuracy (bias) data. These criteria are based on intra-laboratory 

data. 

Method 

Detection 

Limit (mg/L)

Method 

Detection 

Limit (mg/L)

Low Ionic Strength 

Reagent Water 0.007 0.02

High Ionic Strength 

Reagent Water 0.009 0.02

Average 

Percent (%) 

Recovery

Percent Bias Standard 

Deviation

Average 

Percent (%) 

Recovery

Percent Bias Standard 

Deviation

Low Ionic Strength 

Reagent Water 103 2.6 0.5 106 5.5 0.4

High Ionic Strength 

Reagent Water 101 1.2 0.5 105 5.4 0.5

Average 

Percent (%) 

Recovery

Relative 

Percent 

Difference

Average 

Percent (%) 

Recovery

Relative 

Percent 

Difference

99.3 1.0 100 0.0

Matrix

Brighton Treated 

Tap Water

Matrix Spike Analysis Matrix Spike Analysis

EPA 200.7 Hach Method 8026

Initial Precision and Recovery Initial Precision and Recovery
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Measurement of Copper in Water, Method 8026

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Table 5 – Quality Control Performance Criteria for Hach Method 8026

Data Analysis/Discussion

MDL Results

The low ionic strength MDL results for each of the three facilities ranged from 0.004 mg/L to 

0.01 mg/L for the EPA Reference Method EPA 200.7 and 0.02 mg/L to 0.07 mg/L for the Hach 

Method 8026. The high ionic strength matrix MDL results ranged from 0.01 mg/L to 0.01 mg/L 

for the EPA Reference Method EPA 200.7 and 0.02 mg/L to 0.05 mg/L for the Hach Method 

8026. The pooled MDL results for EPA Reference Method EPA 200.7 were determined to be 

0.01 mg/L for low ionic strength matrix water and 0.01 mg/L for high ionic strength matrix 

water. The pooled MDL results for the Hach Method 8026 were determined to be 0.03 mg/L 

for low ionic strength matrix water and 0.03 mg/L for high ionic strength matrix water. The 

regulatory limit established by USEPA for this validation study is ≤ 1.3 mg/L as this is the 

maximum contaminant level (MCL).

Initial Precision and Recovery Results

The IPR average recovery results for low ionic strength matrix water for each of the three 

facilities ranged from 95.0% to 104% for EPA Reference Method EPA 200.7 and 97.3% to 

106% mg/L for Hach Method 8026. The IPR average recovery results for high ionic strength 

Low Ionic Strength 

Reagent Water

High Ionic Strength 

Reagent Water

Initial Precision and 

Recovery Analysis

Average 

Percent (%) 

Recovery

Percent Bias

Lower Limit 

of % 

Recovery

Upper Limit 

of % 

Recovery

95% 

Precision of 

Recovery

Average 

Percent (%) 

Recovery

Percent Bias

Lower Limit 

of % 

Recovery

Upper Limit 

of % 

Recovery

95% 

Precision of 

Recovery

Low Ionic Strength 

Reagent Water 101 1 82.7 118 0.01 101 1 84.9 117 0.02

High Ionic Strength 

Reagent Water 94.8 5 71.0 119 0.02 98.7 1 76.4 121 0.01

Average 

Percent (%) 

Recovery

Percent Bias

Lower Limit 

of % 

Recovery

Upper Limit 

of % 

Recovery

95% 

Precision of 

Recovery

Average 

Percent (%) 

Recovery

Percent Bias

Lower Limit 

of % 

Recovery

Upper Limit 

of % 

Recovery

95% 

Precision of 

Recovery

95.2 5 77.6 113 0.02 94.7 5 79.5 110 0.1

Method Detection Limit (MDL) 

mg/L

0.005

0.006

Method Detection Limit (MDL) 

mg/L

0.03

0.03

Matrix Spike Recovery

Matrix

EPA 200.7 Hach Method 8026

Initial Precision and Recovery (IPR) Initial Precision and Recovery (IPR)

Drinking Water 

Matrix Analysis

Matrix Spike Recovery
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Measurement of Copper in Water, Method 8026

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matrix water ranged from 88.4% to 101% for EPA Reference Method EPA 200.7, and 93.8% to 

105% for the Hach Method 8026. The pooled low ionic strength matrix recovery results for EPA 

Reference Method EPA 200.7 ranged from 82.7% to 118% with a 95% precision of 0.01 and 

84.9% to 117% with a 95% precision of 0.02 for Hach Method 8026. The pooled high ionic 

strength matrix recovery results for the EPA Reference Method EPA 200.7 ranged from 71.0% 

to 113% with a 95% precision of 0.02 and 76.4% to 121% with a 95% precision of 0.01 for Hach 

method 8026.

Matrix Spike Results

The average matrix spike recovery results of the three facilities ranged from 88.5% to 99.3% for 

EPA Reference Method EPA 200.7 and 91.3% to 100% for Hach method 8026. The relative 

percent difference for matrix spike recoveries ranged from 0.0 to 1.0 for EPA reference method 

EPA 200.7 and 0.0 to 6.1 for Hach method 8026. The pooled matrix spike results of recovery 

ranged from 77.6% to 113% for EPA Reference Method EPA 200.7 and 79.5% to 110% for Hach 

Method 8026. The 95% Precision of Recovery results for the EPA Reference Method EPA 200.7

and Hach Method 8026 were determined to be 0.02 and 0.15 respectively.

Conclusion

A validation study was conducted to compare the performance of Hach Method 8026 for the 

measurement of copperin water to that of the EPA Reference Method EPA 200.7. The results 

of the study indicate that Hach Method 8026 is equally effective to that of the EPA Reference 

Method EPA 200.7 for Safe Drinking Water Act, monitoring and compliance reporting programs.