View
223
Download
1
Category
Tags:
Preview:
Citation preview
Portable Contamination Biomonitors
PCB-TOX & PCB-TOX-SPOT
Session I - Basics
Agenda
Recap- bioassays, toxicity, bioluminescence-based assays Key applications Product line overview & history EPA/ETV verification
PCB-TOX (ToxScreen3) - Key applicationsBenefits/features/functionSensitivityKit components & luminometerrs
PCB-TOX-SPOT - Key applicationsBenefits/features/functionSensitivityKit components & luminometer
Summary
Use of Bioassays
A bioassay can be defined as a biological assay performed to measure the effects of a substance on a living organism.
A toxicity bioassay may be run as a screening test (or qualitative), where the toxicity of a sample is compared to that of a control water. The screening tests indicate whether toxicity is present in the sample.
A toxicity bioassay may be run as a definitive test (or semi-quantitative), where several portions of the sample are diluted with varying amounts of the control water and their results compared to the control water. The definitive tests indicate the amount of toxicity presented by the sample.
Additionally, the results of a toxicity bioassay may be measured as either an acute or chronic response.
Bioassays Applications
Mapping to identify toxicity/concentration hotspots
Investigate cause/effect relationships
Detection of “active” or toxic compounds or mixtures not identified by classical analysis
Selection of samples for further/more expensive analysis
Mapping after pollution incidents/accidents
Benefits of Using Bioassays
The use of bioassays provides a holistic approach that allows the toxicity evaluation of the total integrated effect of all constituent components, including toxicants and confounding variables, in a given complex sample matrix. The net assessment is the combined interactive evaluation of additive, antagonistic and synergistic effects of all sample components.
As bioassays directly allow measurement of the potential environmental effects of complex sample matrices, their use for pollution monitoring and control in regulatory framework is becoming increasingly important.
“While there are several different organisms that can be used to monitor for toxicity (including bacteria, invertebrates, and fish), bacteria-based bio-sensors are ideal for use as early warning screening tools for drinking water security because bacteria usually respond to toxics in a matter of minutes”. [EPA - Biological Sensors for Toxicity-Water and Wastewater Security Product Guide]
General Features of a Bioassay Based on Luminous Bacteria
The freeze-dried preparations of luminous bacteria are stable for long periods.
Millions of cells can be introduced to a small water sample, increasing the number of test organisms and reducing the effect of biological variability.
Chemical toxicants that effect cell’s metabolism result in rapid decay of luminescence.
Luminescence may be easily measured by readily available luminometers. High correlation exists between the luminescence test and bioassays that
apply higher organisms, such as fish.
Decreased luminescence
pesticides
Chlorinated hydrocarbons
Heavy metalsdetergents
gasolinepetrol oil
herbicides
Membrane function Protein & lipid synthesis
ATP generationElectron transport
Cell respiration
Luminescence Level Reflects Degree of Toxicity
Product Line Overview & History
ToxScreen1 was first presented in 2001.Verified by the ETV in 2003.
An improved version - ToxScreen2 - was presented in 2003. Verified by the USA-
EPA/ETV in 2006.
Additional improvements were implemented in the latest version - ToxScreen3 -
presented in 2008. Renamed PCB-TOX(ToxScreen3) in 2009.
A dedicated field test kit based on the ToxScreen technology, named, PCB-TOX-
SPOT, was introduced in 2009.
PCB-TOX & PCB-TOX-SPOT are part of CheckLight’s new AquaVerity - a
comprehensive solution to drinking water safety and security.
USA-EPA/ETV Verification Studies
USA-EPA/ETV Verification Studies on Deliberate Contamination of Drinking Water
Sources included Sixteen different rapid toxicity test systems were tested for-
> Sensitivity
> Rapidity
> Field use
> User friendliness
> Sample throughput
Any final solution to the rapid detection problem will likely include a
combination of sensing technologies including bioassays and more
conventional chemical sensors all tailored to the characteristics of individual
water supplies.
An effective bioassay will indicate the presence of something that needs looking
into. But it won't replace qualified hand sampling and further testing.
ETV Conclusions
Out of the 16 different test systems evaluated in 2003 and 2006,
ToxScreen was on the top of the list is terms of -
Sensitivity
Field use
High throughput
User friendliness
ETV/EPA Conclusions
SummarySummary
Rapid toxicity tests are a vital part of a desired Early Warning System for
detecting drinking water contamination.
CheckLight’s ToxScreen test was found to be one of the best rapid toxicity
tests for drinking water.
The test is rapid, sensitive to a broad spectrum of chemical contaminants,
reliable, and user-friendly.
PCB-TOX (ToxScreen3)- Applications
Rapid lab monitoring tool for early detection of chemical toxicity due to spills, accidents, or sabotage in drinking water.
The test can be used to test different water sources - raw waters (including ground water, surface water, recycled water and effluents) and finished drinking water.
It can be used throughout the distribution network to determine dangerous changes in drinking water quality.
It can be used to determine the relative toxicity of inlet and outlet of sewage treatment plants.
PCB-TOX (ToxScreen3) - Benefits
Provides early warning of dangerous water contamination events due to spills,
accidents, sabotage or terrorism.
Ideal for routine monitoring of changes in water quality in surface and ground
water sources.
Able to detect active toxic compounds / mixtures, not identified by classical
analysis.
PCB-TOX (ToxScreen3)- Features
Sensitive - sub-ppm detection levels; for most of the tested chemical agents the test is up to hundreds of times more sensitive than other available bioluminescence-based tests.
Fast - results are obtained in 15 minutes.
Discriminatory - a unique buffer set (Pro-Metal & Pro-Organic) enables
preliminary discrimination between organic toxicants and cationic heavy metals.
Flexible – different testing protocols can be used (quantitative/qualitative)
User-friendly - minimal lab experience is necessary.
Cost effective - extended usability of suspended reagent (up to 5 days). High
sample throughput. Microplate testing format option.
PCB-TOX (ToxScreen3)- Function
Various lab testing protocols are recommended (detailed in the user guide) to enable either:
Rapid screening of multiple samples for qualitative determination of toxicity
Semi-quantitative measurements to determine degree of toxicity of discrete samples.
Low cost per test encourages frequent testing for rapid response to changing conditions in water quality.
ToxScreen3 Sensitivity - 1
Sensitivity as tested in Pro-Metal Buffer
IC50 – the minimal concentration of the toxic agent that results in 50% inhibition of luminescence.
LDL - the minimal concentration of the toxic agent that results in 20% inhibition of luminescence
NF – not found
ToxicantIC50 (mg/L)LDL (mg/L)
ToxScreen3MicrotoxTMToxScreen3MicrotoxTM
Arsenate (5)0.091.500.015NF
Cadmium(2)0.241.40.0820
Lead(2)0.18110.060.6
Selenium(2)0.15NF0.0333
ToxScreen3 Sensitivity - 2
Sensitivity as tested in Pro-Organic Buffer
ToxicantIC50 (mg/L)LDL (mg/L)
ToxScreen3MicrotoxTMToxScreen3MicrotoxTM
2,4,5-T0.1352.50.05NF
DDT0.0570.01NF
2,4-Dintrophenol0.210.60.05NF
KCN0.458.40.10.73
Arsenic(3)6NF27.8
2,4-D0.15.70.04NF
Chromium(6)0.07310.0315.3
PCB-TOX (ToxScreen3)- Key References & Case Studies
The test kit has been routinely utilized by the North Carolina DWQ Aquatic Toxicology Unit for assessing watershed toxicity.
The test kit has been used by various US-based water utilities to determine potential contamination to their water sources during high terrorist alert periods.
The test kit has been routinely used by research groups in Japan to assess leachate toxicity.
The test kit has been used in order to monitor the toxicity in the tidal estuaries in Europe, as part of the WFD monitoring requirements.
Kits & Accessories Components
PCB-TOX (ToxScreen3):
Freeze dried bacteria box
Assay Buffers box
Empty tubes
Portable luminometer
PCB-TOX- SPOT:
Freeze dried bacteria boxAssay Buffers boxEmpty tubes
Portable low-cost luminometer
Pipettor & tipsTimerPortable incubatorCarrying case
PCB-TOX (ToxScreen3) -Kit components & Luminometer
The kit holds: 5 vials of freeze dried bacteria 50 ml of concentrated Pro-Metal &
Pro-Organic buffers (each) 5ml storage Buffer 1ml concentrated positive controls
(metal & organic, each) 500 empty test tubes
The luminometer is a portable photomultiplier-based instrument.
Sensitivity - 1fmol ATP Data storage- 2000 points Dynamic range- 106
Interface- RS232 Weight- 2kg net
PCB-TOX-SPOT -Kit components & Luminometer
The kit holds: 25 vials of freeze dried bacteria 20 ml of concentrated Pro-Metal & Pro-
Organic buffers, each. 23 ml Hydration Buffer 200 empty tubes 2.5 ml of concentrated positive controls
(metal & organic, each)
The luminometer is a portable photodiode- based instrument.
Weight- 250gr net
Dynamic range - 105
Data storage- 2000 points
Interface- USB
LUM-KK-01
PCB-TOX-SPOT -Accessories
The starter kit is supplied with the following accessories-
Carrying case (11x40x50cm)
Pipettor (0.1-1ml)
425 pipettor tips plus storage box
Two boxes to hold the empty test tubes
Timer
Incubator block (30°C) with a car cigarette plug connector
PCB-TOX-SPOT -Key Applications & Benefits
Designed for field operation, the test provides early warning of dangerous water
contamination in emergency situations due to spills, accidents, sabotage or
terrorism.
PCB-TOX-SPOT enables rapid on site screening to determine changes in water
quality in raw and treated drinking water sources and remote locations throughout
the distribution network.
The test can be used by emergency response teams, water companies, health
and environmental supervising & monitoring authorities, municipal water system
authorities, military units, etc, for: Mapping after pollution incidents / accidents Selection of samples for further/more expensive analysis Mapping to identify toxicity / concentration hotspots
PCB-TOX-SPOT -Features
Sensitive - sub-ppm detection levels; for most of the tested chemical agents the test is up to hundreds of times more sensitive than other available bioluminescence-based tests.
Fast - results are obtained in 15 minutes.
Discriminatory - a unique buffer set (Pro-Metal & Pro-Organic) enables preliminary discrimination between organic toxicants and cationic heavy metals.
User-friendly & Robust - minimal skill and training is necessary. Can be used anywhere.
Cost effective – saves valuable time and money by minimizing shipment of samples to distant labs.
Summary - 1
FeaturePCB-TOX (ToxScreen3)PCB-TOX-SPOT
Tests per freeze dried bacteria vial
482
Preparation time (pre-incubation of hydrated bacteria)
3 hrs pre-incubation once a week
10 min
Life span of hydrated bacteria
One weekOne hour
Optimal assay temperature
30°C
(Operational: 18°C - 35°C)
Nature of generated dataQualitative & semi-quantitative
Qualitative
Comparative sensitivityOrganics - very high
Metals - very high
Summary - 2
FeaturePCB-TOX (ToxScreen3)PCB-TOX-SPOT
Data analysisDownload data from luminometer to PC. Transfer data to programmable excel module for automatic calculation of toxicity
Recommended for Routine lab testing Screening large numbers of samples Determination of relative toxicity
On site testing in emergency situations
Recommended