The COVID-19 pandemic has severely impacted public health and the worldwide economy. Converging evidence from the current pandemic, previous outbreaks and controlled experiments indicates that SARS-CoVs are present in wastewater for several days, leading to potential health risks via waterborne and aerosolized wastewater pathways1. Water testing for drinking water, process water and wastewater have become more important than ever. Due to the partial shutdown and the limited resources labs are facing high sample load across all the industries. Many of the regulatory bodies, such as the US EPA, recommends wet chemical methods for drinking water and waste water applications.
Testing many samples for diverse parameters and concentrations can create a bottleneck with limited lab resources. Hundreds of samples make their way to in-house or contract quality testing laboratories every day, but traditional wet chemistry analysis is a slow process. With a goal of achieving high throughput wet chemical analysis, without losing selectivity or sensitivity, this blog post shares the eight different ways throughput could be improved for wet chemical water analysis by implementing the following:
- Optimized analytical workflow
- Parallel analysis
- Consolidated analysis
- Efficient alternative test protocol (ATP)
- Results reliability
- Ready to use reagents and standards
- Intelligent liquid handling
- Walkaway efficiency
Depending on the analytical lab, the importance of the priority of these ways to improve the throughput could be different.
Migrating from traditional wet chemical workflow vs. high-throughput workflow
Typically, incoming water samples are split into multiple portions and taken to different wet chemical analytical instruments, such as titration, spectrophotometry, ion meters, or pH/conductivity meters, and flow injection analyzers (FIA) are used to test multiple water parameters. Each test requires a separate sample and often multiple sequential steps which extends the testing process. With slow processes and the need for specialist staff to run and monitor equipment, water quality testing is labor-intensive, time-consuming and inefficient.
Traditional wet chemistry methods like titration or ISE sequentially measure individual test parameters. For each parameter, dedicated ISE are necessary and have limited shelf lives. Each titration parameter needs a dedicated burette and sensor, as the number of parameters per sample increases, the overall system complexity increases. Similarly, the flow analyzers are batch analyzers that are configured for few parameters. Testing for multiple parameters, therefore, requires multiple techniques and instruments, resulting in long hands-on sample and response times, reduced throughput and increased per-analysis costs. What’s more, significant investment in ongoing staff training and instrument maintenance is also required.
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Traditional workflow for a basic water analysis testing -pH, conductivity, alkalinity and hardness involves sequential measurements:
- Three sample portions, 50 to 100 mL – for each parameters, conductivity, pH, alkalinity and hardness
- Two titrants – for alkalinity and hardness
- Four sequential steps
- Conductivity measurement
- pH measurement
- Alkalinity titration
- Hardness titration
- Multiple rinsing of sensors and the titration vessel between the measurement and titration to eliminate the carry over considerably reduces the throughput
On an average, basic water analysis for these four parameters would take nine to 12 minutes per sample, depending on the type and extension of automation. For a lab that requires 100 samples per day testing it would amount to 15 to 20 hours. Parallel titration systems are complex and adds operational difficulty.
High throughput water analysis workflow
Consolidated multiparameter discrete analysis now offers a solution to these difficulties and offers high throughput wet chemical analysis workflow. Discrete analyzers, which consolidate and simultaneously test for up to 20 parameters — using a single instrument with a single operator. Gallery and Gallery Plus discrete analyzers are easy-to-use, automated systems that allow laboratories to simplify their testing with dual benefits: time and cost savings. All necessary analysis steps are automated, providing true walkaway time for the operator. Both Gallery and Gallery Plus instruments provide an integrated platform for two measurement techniques, photometric and electrochemical (pH and conductivity), which can be run simultaneously. Parallel determination of several analytes from a single sample as well as the presence of several automated features ensures analytical efficiency.
pH and conductivity for 100 samples can be tested simultaneously in less than 90 minutes, while the system is measuring alkalinity, hardness and other parameters. While traditional analysis requires multiple wet chemistry methods and, therefore, multiple samples, the Gallery discrete analyzer consumes a maximum of 300 μL of sample per test, can test for up to 20 parameters per sample, and runs up to 200 tests per hour.
It is a fully integrated walkaway solution. The testing workflow is easy to learn, and can be left unattended, improving throughput, system uptime and staff productivity. For laboratories that perform routine process water, drinking water and wastewater analysis while experiencing increased demand for their routine analytical services, the Gallery and Gallery Plus discrete analyzers provide increased throughput.
- Nat Sustain(2020). https://doi.org/10.1038/s41893-020-00605-2
- Executive Summary: How Discrete Wet Chemical Analysis is bringing Flexible, Cost-effective Multiparameter Testing to the Beverage Industry
- Executive Summary: Process-Water Characterization using Discrete Analyzers and Ion Chromatography
- Brochure: Solution for Routine and Comprehensive Water Analysis