3M Food Safety
Technical Bulletin
Title: Comparison of Improved 3M™ Clean-Trace™ Water Plus –
Total ATP (AQT200) Performance to Current Product
(AQT100)
Number:
TB.185828
Effective Date:
August, 2012
Supersedes: New
Technology Platform:
Hygiene Monitoring
Originating Location:
St. Paul, Minnesota
A study done by 3M Food Safety on 3M™ Clean-Trace™ Water Plus – Total ATP (AQT200) for
verification testing shows the AQT200 product’s performance is better than or equivalent to the
performance of the 3M™ Clean-Trace™ Water – Total ATP (AQT100).
The study compares these characteristics of the two products: Shelf-life, optimal test temperature,
RLU background levels, ATP limit of detection, detection of various micro-organisms,
repeatability and reproducibility, and the effect of sanitisers and biocides.
Shelf-life
The study shows that for maximum shelf-life, you can store AQT200 at 2oC-8oC (36°F - 46°F) for
12 months, which is equivalent to AQT100. You can also store AQT200 at 21°C - 25°C (70°F 77°F) for 2 months shelf life. Shelf-life for ATQ100 in these conditions is 2 weeks. Shelf-life for
AQT200 is better than shelf-life for AQT100.
Optimal Test Temperature
The optimal test temperature for AQT200 is 15 oC– 30 oC (59° – 86° F), which is better than the
optimal test temperature for AQT100, 15 oC-25 oC (59° – 77° F).
RLU Background levels
AQT200 test devices and AQT100 test devices (n=2 batches of 200 test devices per batch) were
activated without collecting water samples to measure RLU background levels.
3M Food Safety
3M Center
Bldg 275-5W-05
St. Paul, MN 55144-1000
USA
1-800-328-6553
TB.185828 Page 1 of 5
© 3M 2012. All rights reserved.
3M Food Safety
Technical Bulletin
Boxplot of AQT100 (#1208), AQT200 (#555)
Boxplot of AQT100 (#1169), AQT200 (#444)
100
50
80
60
30
RLU
RLU
40
40
20
20
10
0
0
AQT100 #1169/NX1
AQT100 #1208
AQT200 #444
AQT200 #555
The test results showed the background levels for AQT200 are lower and more repeatable with
less variation than the background levels for AQT100. Although the background RLU levels for
ATQ200 are lower, the change does not require a re-evaluation of your current pass/fail limits set
in your 3M™ Clean-Trace™ NG Luminometer since most customers set their pass/fail limits at
much higher levels. However, customers who have set their pass/fail limits low to improve their
cleaning efficiency may wish to review their pass/fail limits. Background levels for AQT200 are
better than background levels for AQT100.
Repeatability and Reproducibility
A repeatability and reproducibility study was done on AQT200 using 5 operators. All of the
operators obtained results which met the CV% specification with an overall average of 9.2%.
ATP Limit of Detection
Serial dilutions of ATP positive control were made and measured using AQT200 test devices (n=5
for each dilution). AQT200 test devices (n=10) were activated without collecting water samples to
measure RLU background levels. The limit of detection was defined as the mean plus 2 standard
deviations of the RLU background levels.
The test results show the limit of detection is 5 RLU for batch#111 of the new AQT200 product,
easily detecting 1 femtomole (10-15 mole) of ATP, which is the limit of detection for AQT100. Refer
to the standard curve below.
3M Food Safety
3M Center
Bldg 275-5W-05
St. Paul, MN 55144-1000
USA
1-800-328-6553
TB.185828 Page 2 of 5
© 3M 2012. All rights reserved.
3M Food Safety
Technical Bulletin
A second batch of AQT200 was tested (#333), and the test results show the limit of detection is 6
RLU. The limit of detection for AQT200 is equivalent to or better than the limit of detection for
AQT100, which is 1 femtomole.
Detection of Micro-organisms
The test does not make any claims for the detection of specific micro-organisms, rather the level of
ATP present in water samples is a direct indication of levels of contamination present in the water
samples from product residues as well as microbial cells.
However, the study included a comparison of the performance of AQT200 and AQT100 in
detecting of a selection of gram positives, gram negatives, yeasts, lactobacillus and industryrelevant micro-organisms such as Acetobacter sp. The test results show detection of these various
micro-organisms by AQT200 is equivalent to detection by AQT100. Statistical T-test at 250 RLU
level Acetobacter (P-Value= 0.915). Detection of micro-organisms for AQT200 is equivalent to
detection of micro-organisms for AQT100.
Effect of sanitisers and biocides
Sanitisers and biocides are widely used in the field in the applications tested by AQT100 (cooling
towers, paper/pulp process waters). A wide range of biocides were tested at working strength to
compare the performance of AQT200 to AQT100. Both products were tested with and without
biocide. The “% Activity” in the presence of biocide for AQT100 and AQT200 was determined
Refer to the table below.
3M Food Safety
3M Center
Bldg 275-5W-05
St. Paul, MN 55144-1000
USA
1-800-328-6553
TB.185828 Page 3 of 5
© 3M 2012. All rights reserved.
3M Food Safety
Technical Bulletin
Biocide / Sanitiser
DBNPA –based compound
(DiBromoNitroPropionAmide
THPS –based compound (Tetrakis
Hydroxy Phosphonium Sulphate,
Pyrophosphate-based corrosion/scale
inhibitor
Scale inhibitor
Chlorine
Bronopol-based compound (2-bromo-2nitropropane-1,3-diol)
BAC
(Quaternary Ammonium compound)
CTAB (Quaternary Ammonium
compound)
Glutaraldehyde –based compound
Isothiazolinone –based compound
Pyrophosphate- based corrosion/scale
inhibitor
Pyrophosphate –based corrosion/scale
inhibitor)
Working
Strength
100ppm
% Activity
(Average of 2
batches)
AQT100 AQT200
97
103
100ppm
105
98
150ppm
100
92
150ppm
1ppm
70ppm
100
107
91
103
99
103
10ppm
99
100
50ppm
100
101
50ppm
10ppm
15ppm
95
87
104
104
103
98
150ppm
100
94
Some sanitisers and biocides, particularly anti-corrosion chemicals, contain pyrophosphate. It is
known that the new AQT200 formulation can be affected by pyrophosphate. At the working
strength for these chemicals, the performance of AQT200 was shown to be acceptable.
Effect of CIP Product Residues
A wide range of product residues spanning dairy, brewing and juice production were tested to
compare the performance of AQT200 to AQT100. Serial dilutions of typical products in water
were tested. The test results showed detection levels of typical products for AQT200 were
equivalent to AQT100. Performance data for lager beer showed equivalent detection at a typical
pass/fail level of 150 RLU. Statistical T-test (P-Value = 0.946)
Performance data for whole milk shows equivalent detection. Note that RLU values were slightly
lower for AQT200 compared to AQT100 at the 0.1 dilution level of whole milk, but are still well
above fail levels at >10,000RLU. This effect is due to phosphate in milk affecting the new AQT200
formulation. This dilution level of milk is not practically significant as levels of milk in CIP rinse
waters would never be as high as this, and the maximum practical range for detection is the 0.01
dilution level. Results at the 0.01 dilution level and lower are equivalent.
3M Food Safety
3M Center
Bldg 275-5W-05
St. Paul, MN 55144-1000
USA
1-800-328-6553
TB.185828 Page 4 of 5
© 3M 2012. All rights reserved.
3M Food Safety
Technical Bulletin
3M Food Safety
3M Center
Bldg 275-5W-05
St. Paul, MN 55144-1000
USA
1-800-328-6553
TB.185828 Page 5 of 5
© 3M 2012. All rights reserved.