Product Information

Upcoming Changes To CHEMetrics Ammonia Test Kits

CHEMetrics Ammonia Test Kits Update

The CHEMetrics Nessler Ammonia product line has been providing a reliable and straightforward means to measure ammonia in water for decades. The K-1503 and K-1523 Vacu-vials tests have been very successful, despite the limitation of the 2-month shelf-life.

In September 2023 we addressed the short shelf-life of K-1503 by launching K-1513, an improved Nessler Ammonia Vacu-vials test kit, with a 12-month shelf-life and wider measurement range. After seeing the positive reception of K-1513 we are following up with the launch of K-1533 in a few months. K-1533 will be a replacement for K-1523 and offer the new 12-month shelf-life and a larger measurement range. As we discontinue K-1503 and K-1523, the longer shelf-life products K-1513 and K-1533 will be their direct replacements.

The new K-1513 and K-1533 kits utilize the same Direct Nesslerization method of analysis so you can expect the same precision and accuracy that K-1503/K-1523 provided. Besides the improved shelf-life and wider testing range, the primary differences are that the new test procedures require an additional activator solution. Table 1 provides a comparative summary of the features for the old and new products.

A table detailing the current products and what products are replacing them.

We understand that changing part numbers and test procedures can be inconvenient. However, we believe the shelf-life extension and expanded testing range will reduce product ordering frequency and open up new measurement range options for our customers.

What Do I Need to Keep Testing?

In early Spring 2024, if you were previously using K-1503 you will be prompted to purchase K-1513, and if you were previously using K-1523, you will be prompted to purchase K-1533. Since the test procedures have changed it will be critical to review the new kit instructions.

For customers using CHEMetrics V-2000 or V-3000 photometers, you may need to update your instrument software to the most current method revision available on our website. (V-2000 method update and V-3000 method update). Refer to Table 2 for new program # assignments and Photometer Method Revision requirements. Additionally, customers using spectrophotometers will need to use the new calibration equations printed in the kit instructions.

A table detailing the different methods for each instrument CHEMetrics provides.

Questions?

If you have any questions or concerns regarding the changes to the ammonia test kits, we encourage you to reach out to our customer service team via our website or by phone at 800.356.3072. Thank you for choosing CHEMetrics for your water testing needs.

CHEMetrics Q1 2024 Product Line Updates

Introduction

Q1 2024 was a busy time at CHEMetrics! We have made a lot of updates to our product lines and website to help increase our production flexibility, response time, order accuracy, and on-time delivery. These changes encompassed product labels, packaging, new products, and part # retirements. To help make sense of the different part number changes, we thought a summary might help!

Discontinued Part #s

Several CHEMetrics’ part #’s were “retired” in Q1 2024. These changes were part of an effort to streamline manufacturing processes, increase regulatory compliance, and improve our inventory management.

Table 1 lists the discontinued part #s, with their corresponding direct replacement product. Note that although the accessory solution packs (A-xxxx) and CHEMets refill (R-xxxx) catalog #’s are changing, the kit part #s (K-xxxx) they are components of, are NOT changing.

The formulations for the impacted products have NOT changed. The direct replacement is identical to the discontinued products. This means that there is no analytical performance difference between the discontinued product and the replacement.

Historically components were assigned analyte specific part #s even if they were identical. Now, we offer a single part # for all test kits, rather than separate ones.

For example, catalog #s A/S-1600 (bromine), A/S-5501 (hydrogen peroxide), A/S-7400 (ozone), and A/S-7900 (peracetic acid), share identical reagent formulations. These part #s have been replaced with a single part # A/S-2500.

Similar part numbering consolidation is occurring for CHEMets refills. For example: R-7904 was a Peracetic Acid CHEMets refill that was labeled “R-7904 Peracetic Acid”. It is now labeled as “R-7904 Bromine/PAA/Peroxide” because these analytes now share the same CHEMets refill part #.

Table 1: Discontinued products and Replacements

This is a table detailing the discontinued part numbers, the direct replacement part, the kits they are components of, and the analyte of interest.

 

New Products as a Result of This Change

Technically, A-6900 (cadmium) and A-6905 (zinc) foil packs are not new products. They used to be packaged with their corresponding R-6902, R-6904 and R-6905 nitrate CHEMets refills. Now that R-6902/6904 and R-6905 part #s are retired and replaced with R-7002, (refer to Table 1), these foil packs are being packaged separately.

NOTE: This means that when nitrate customers want to re-order their consumables, they MUST use two part #s when ordering – R-7002 PLUS A-6900 or A-6905.

A Note About Catalogs

Many of you have been requesting the CHEMetrics 2024 catalog. Due to these product line changes, we have delayed the launch of our catalog. We will issue the catalog once the product changes are complete. This will ensure you have a reliable catalog.

Questions?

 If you have any questions or concerns about these product changes please contact customer service through our website or via phone at 800.356.3072. Thank you for choosing CHEMetrics and keeping Simplicity in Water Analysis.

New Product: Test Kits for Corrosion Inhibitors Utilizing Rose Bengal Chemistry

Two New Filming Amine Test Kits Available

CHEMetrics has developed new test kits utilizing the Rose Bengal chemistry for measuring residual corrosion inhibitors like film forming amines (FFA) in boiler systems.

K-1013 features our Vacu-vials® ampoules and is compatible with a CHEMetrics V-3000 photometer or spectrophotometers that accept a 13mm round cell. Alternatively, a K-1013 DR 900 user program is available for download. This kit comes with enough consumables to conduct 30 corrosion inhibitor tests. Results are provided in ppm Octadecylamine (ODA) or Oleylamine (OA).

K-1013 Filming Amine Test kit and all of it's contents

K-1006 features our CHEMets® ampoules for visual colorimetric analysis. Color development in the CHEMets ampoule is compared against the provided comparators to obtain a result. This test kit comes with two comparators allowing for measurements in the ranges of 0-2 and 2-6 ppm ODA or OLA. The kit contains everything needed to conduct 30 tests.

K-1006 Test Kit for Filming Amines and all of it's contents.

Test Kit Applications

Film forming amines, sometimes known as film forming amine products (FFAP) or film forming products (FFP), are used in high pressure boilers, cooling systems, and heat recovery steam generators (HRSGs) to prevent corrosion and minimize corrosion product transport. The Rose Bengal method is a popular test method for measuring these compounds in boiler water or condensate. Under acidic conditions the amines react with Rose Bengal to form a magenta-colored complex in direct proportion to the concentration of simple filming amines such as Octadecylamine (ODA) or Oleylamine (OA).

What are the Benefits of the CHEMetrics Rose Bengal Test?

Rose Bengal is a widely accepted method for measuring filming amines but most commercially available test kits have one key drawback. Rose Bengal dye adheres to glass and labware to the point of staining. Typically, it is necessary to clean glass cuvettes with solvents to prevent introduction of measurement bias. Other labware may need to be dedicated for Rose Bengal use.

With the CHEMetrics self-filling ampoule technology the dye is packaged in the single-use ampoule. No cuvettes are required since the ampoule is used to make the measurement. Staining problems are eliminated. Our convenient corrosion inhibitor test kits save labor and costs associated with solvent cleaning and disposal.

The ampoules contain a premeasured dose of reagent for a single test. After the addition of acidifier solution to the sample simply snap the ampoule in the sample and wait 2 minutes for color to develop to obtain your results.

Rose Bengal Method compared to Methyl Orange Method

CHEMetrics offers two different chemistries for measuring film forming products, the Methyl Orange method, and the Rose Bengal method.

These two methods are very different in their chemistries. Most film forming amine products are proprietary blends of different chemicals. This can make testing for them quite difficult as the components can vary based on the FFA blender/supplier. We encourage customers to try both test methods to determine which one works best for their product and application.

The Filming Amine Test Kits utilizing the Rose Bengal Chemistry are available now on the CHEMetrics website. Order online or contact us at 800-356-3072 to place your order today.


Upcoming Changes to CHEMetrics VACUettes® High Range Visual Colorimetric Tests

What is Changing?

In the coming days you will notice a change to the packaging for all VACUettes products. The VACUettes capillary tips will no longer be attached to the test ampoule. Instead, the tips will now be supplied in a small plastic box packaged alongside the CHEMets refill containing the ampoules. If you are ordering a VACUettes test kit (Catalog Numbers that start with a “K”), the box containing the tips will be inside the plastic case for the test kit. If you are purchasing a VACUettes refill (Cat #’s – beginning with an “R”) the box of tips will be packaged with the CHEMets refill and updated product instructions in a resealable plastic bag.

The part numbers for these products ARE NOT changing for this change in packaging.

VACUettes Packaging will now have the tips in a small plastic box within a resealable plastic bag.

An example of the new VACUettes product packaging.

Before performing a test, the VACUettes tip will need to be attached to the tip of the CHEMets ampoule. The updated instructions will detail how to put the tip on the ampoule. Kit instructions are also available on our website on the individual kit and refill product pages.

What’s Next for the VACUettes Product Line?

In the coming months we will be discontinuing the entire VACUettes product line, but we will replace it with a new line of high range test kits. The new line of test kits will offer improved ease of use along with the same direct read convenience that VACUettes tests provided. More information on these new products will be coming soon.

Can I Purchase More VACUettes Test Kits Now?

We will continue to offer VACUettes test kits for several months until our stock runs out. A full list of VACUettes products can be found on this page. You can place orders online at chemetrics.com, through your AquaPhoenix sales rep, or via phone at 800.356.3072.

I Have a Question!

If you have any questions or concerns you can fill out a contact us form or talk to a customer service representative at 800.356.3072. We will continue to update our blog with new information regarding the VACUettes change so please check back soon. We thank you for your business!

NEW A-2024 Ammonia Single Analyte Meter Now Available

A New Meter for Measuring Ammonia

To provide even more convenient water testing options, CHEMetrics now offers the A-2024 Single Analyte Meter (SAM) for the measurement of ammonia in water. The A-2024 SAM is an affordable portable ammonia photometer designed to work with the currently available K-1413 and K-1513 Ammonia Vacu-vials test kits.

Figure 1: The A-2024 SAM provides accurate and reliable results for ammonia water testing.

Whether you prefer testing with K-1413’s hydroxybenzyl alcohol chemistry or the Direct Nesslerization chemistry of K-1513, the new ammonia SAM is perfect for starting a new testing regime or integrating into your current schedule. Results are provided in ppm (mg/L) ammonia-nitrogen (NH3-N) on a clear screen. Featuring compatibility with two different methods, A-2024 can

measure at the following ranges:

  • K-1413 Range: 0 – 3.00 ppm
  • K-1413 Range: 0 – 60.0 ppm
  • K-1513 Range: 0 – 10.0 ppm
  • K-1513 Range: 0 – 150 ppm

The SAM fits comfortably in hand and runs on four AAA batteries for approximately 5,000 tests. It holds 15 data sets in memory making it perfect for testing in the field or in the lab. Every unit comes with a light shield, screwdriver, batteries, instructions and a 1-year warranty so you can test with confidence. CHEMetrics Vacu-vial test kits are sold separately so you can choose the product that best meets your testing needs.

You can purchase a unit right now on our website, by phone at 800.356.3072, or by email at orders@chemetrics.com. (International customers: Please contact your local CHEMetrics distributors.)

New Monochloramine Water Analysis Test Kits

CHEMetrics is pleased to announce the release of two new test kits employing the hydroxybenzyl alcohol  (HBA) method to measure monochloramine in water. These test kits are perfect for drinking water and wastewater testing applications in the field and lab. This method measures only monochloramine and expresses the results as ppm (mg/L) monochloramine as chlorine (NH2Cl-Cl2) in just 5 minutes.  (Monochloramine in water reacts with HBA in the presence of sodium nitroferricyanide to form a green colored complex in direct relation to the concentration of monochloramine.)

The CHEMets® K-6802 visual test kit measures from 0-20 ppm NH2Cl-Cl2 utilizing vacuum sealed self-filling ampoule technology. It comes with everything needed to perform 30 tests packed into a convenient plastic case.

The Vacu-vials® K-6803 instrumental test kit measures in the following ranges depending on the instrument:

  • CHEMetrics V-2000 Photometer: 0 – 15.0 ppm NH2Cl-Cl2 (Prog. # 117)
  • CHEMetrics V-3000 Photometer: 0 – 8.00 ppm NH2Cl-Cl2 (Prog. # 117)
  • Spectrophotometer: 0 – 8.00 ppm NH2Cl-Cl2

K-6803 uses self-filling ampoules that are compatible with any spectrophotometer that accepts a 13mm round cell. The kit comes with everything needed to perform 30 tests packaged into an environmentally-friendly cardboard box.

For more information about our HBA test kits for monochloramine, visit www.chemetrics.com, call 800.356.3072 or fill out a form to contact Technical Services.

Introduction to Freshwater Monitoring and Water Rangers Products

Announcing A New Partnership

At CHEMetrics, our goal is to deliver water testing tools and resources that are accurate, affordable, and easy to use. With that in mind, we’re proud to announce our partnership with the Canada-based Water Rangers organization. Water Rangers has created water testing kits designed for communities, schools, and passionate citizen scientists who help in the effort to maintain healthy local freshwater ponds, lakes, and rivers. Water Rangers test kits have been tested against professional equipment and, like CHEMetrics-branded products, deliver accurate results without need for a lab. So far, thousands of volunteers in over 20 countries have joined the Water Rangers movement. CHEMetrics has been proud to have our K-7512 Dissolved Oxygen Test Kit as a part of the Water Rangers kit, and now we are excited to offer Water Rangers products for sale directly from www.chemetrics.com to meet your freshwater testing needs.

Water Rangers Partners

Figure 1: Water Rangers is funded and supported by these great organizations

How Does Water Testing Help?

There are often large gaps in water quality data for research studies. Without long term data, it is difficult to detail what is happening with a body of water. With the Water Ranger’s open data platform, your test results can be uploaded to a database and made available to other volunteers and scientists. The location-based platform makes it possible to keep track of measurements for a body of water over a long period of time. Those measurements can ultimately strengthen the scientific community and help drive leaders to make better resource management decisions. To learn more about Water Rangers open data platform visit https://app.waterrangers.ca/.

Which Test Kit is Right For Me?

CHEMetrics offers two Water Rangers test kits. Both are easy to use and compatible with the open data platform.

Freshwater Explorer Test Kit (K-0020) – This kit is designed for analysts of all ages and comes with a new and improved field guide that includes step-by-step directions to help the user conduct each test, understand the results, and record observations. All items come packaged in a durable backpack for easy field travel. No previous testing experience is required. This kit is ideal for small organizations and individuals. With this kit you can measure temperature, water clarity, depth, chlorine concentration, pH, alkalinity, hardness, total dissolved solids, and dissolved oxygen concentration. Gather data about your community’s lakes and rivers without breaking the bank.

Freshwater Education Test Kit (K-0010) – This test kit is specifically designed for educators who want to help create the next generation of water testers. Also bundled in an easy-to-carry backpack, this kit comes with enough supplies to serve the testing needs of 20 students. The accompanying teacher guide provides detailed lesson plans and shows educators how to perform every test. Even more lesson plans are available through the Water Rangers website (waterrangers.ca)

Contents of the Water Rangers Education Kit

Figure 2: The Freshwater Education Kit fits all of this in convenient portable bag.

The Freshwater Kit Restocking Pack (R-0010) –  For the user who needs to replace their kit’s consumables, this bundle will help you get back to testing right away. It contains conductivity calibration solution, a CHEMetrics R-7512 dissolved oxygen refill pack, a container of 50 test strips (for chlorine, pH, alkalinity, hardness), and a fridge magnet to remind users of monthly testing times.

Are you ready to test your local water sources and start supporting your community? Place your order for a Water Rangers test kit right now at chemetrics.com.

Building a Panel to Make the Water Treaters Life Easier

Around AquaPhoenix, we are always talking about continuous improvement and looking for ways to advance our manufacturing operations and the customer experience. We feel the same principles of continuous improvement should also be applied to the daily life of a water treater. After all, improving efficiency and reducing problems should always be on our minds.

Recently, Blaine Nagao, CWT, and President of our Equipment Division went out to the shop floor and started creatively thinking about ways water treaters can improve their daily routine. He started grabbing things from our shelves, cleared a spot on a workbench, and built his ideal panel.

Below, he outlines what you can do to a panel that will make your program work more effectively. Hopefully, these ideas make you look at your day-to-day routine and see areas for improvement, and the next time you need to build and install a new system, you can incorporate some of these job-enhancing features! How can you make a panel build serve you and your customer better?

Ask yourself these questions:

  • What makes your job easier?
  • What makes a customer’s job easier?
  • What makes your program work effectively?

Work Surface

We’ve all balanced our laptop or test kits on a drum that may be covered with chemical or something else and gotten it all over our stuff. That’s not what tanks were made for. Tanks and drums were made for holding chemical and for pumping out of.

Integrate a work surface onto the panel. Integrate lighting or shade if needed. How many times do you have to go to a panel out by a cooling tower and you have to put your jacket over or hold your hand over to read the screen? That’s not a failure on the controller manufacturer’s part. An LCD screen does not work well in direct sunlight. In contrast, you may have to run tests in the evening or in a dark basement. Why not put a light on your panel? It’s low cost and easy to do.

Internet Access

Receive alarms, emails and upload data from anywhere internet service is available. Wi-Fi is great because you most likely will have a laptop with you on location. Most manufacturers have routers on their controllers however, many people do use that feature as a hotspot. Create a password that only you know to eliminate the risk of an operator using all of your data.

Our routers have an extra waterproof ethernet port. You can plug your laptop right into that and access your controller. It’s nice to have a port that you can access without opening the controller.

Storage for Parts and Coupons

There is plenty of open space on a panel. Make use of that space by designing holders for all of those miscellaneous items. Save time and expense by eliminating those ‘quick’ trips to the hardware store.

Examples:

  • Corrosion coupons
  • Coupon envelopes
  • Spare holder screws/nuts
  • Corrator tips
  • Injection valves
  • Electrodes, etc.

It may seem like a lot of money upfront to keep these items stocked, but it does not compare to overnighting just one of those items or having to not feed product, or compromise performance.

Toolless Fittings

Order parts with toolless fittings. A simple union fitting on an injection valve is much better than trying to pull the tubing off of an injection valve to check to see if it’s clogged.

Consider adding a tee with a plug to your next panel build. If your rejection line clogs, you can inspect it. Valve it off and run a cleaning/rod brush on the end of a drill to clean out those clogged-up tees and lines.

If you replace your injection valve, tees, and coupons, with toolless fittings, you will eliminate the need for additional tools to service your system.

Learn More

To see the entire presentation, including tips for choosing the correct products for your panel, click here to see the entire on-demand recording.

 

Testing for Persulfate with CHEMetrics K-7870 and K-5543

Testing for persulfate is easy with the CHEMets® visual test kit K-7870. With this test you can measure anywhere between 0 to 70 ppm sodium persulfate in just 90 seconds. If you are in need of an instrumental test, CHEMetrics hydrogen peroxide Vacu-vials® kit K-5543 can be used to measure sodium persulfate by using a slightly modified procedure. Simply fill the sample cup, insert the Vacu-vials ampoule and snap the tip. Now mix and wait 90 seconds. Multiply your peroxide test results by 7 to convert to ppm sodium persulfate. Watch the video below to see these tests in action!

 

Environmental Dissolved Oxygen Testing: CHEMetrics Test Kits vs. Winkler Titration

Significance of Dissolved Oxygen in Aquatic Environments

Measuring the concentration of dissolved oxygen (DO) in natural waters is vital in assessing the overall health of aquatic environments. While every ecosystem is different, water bodies need approximately 6 – 10 mg/L (ppm) DO to support aquatic life. Low dissolved oxygen concentration is a strong indicator that sources of pollution are negatively impacting water quality. Often, low levels of DO can be traced to non-point sources such as stormwater runoff. Typical contaminants stemming from runoff are petroleum hydrocarbons and excess fertilizer which supplies plant nutrients that create algae blooms. As the algae decompose the oxygen in the water is consumed causing hypoxia (low levels of DO) or anoxia (complete absence of DO). In a healthy water environment, oxygen can be replenished in the water naturally through the atmosphere and photosynthesis by aquatic plants. Flowing water such as streams and rivers will have greater levels of DO due to natural aeration of the water caused by agitation.

Oxygen solubility in water is dependent upon temperature, atmospheric pressure, and salinity of the water. When assessing the dissolved oxygen concentration in a body of water, it is important to consider all of these factors. Oxygen solubility is often expressed in terms of percent (%) air saturation. Air saturation tables provide theoretical values of dissolved oxygen at 100% air saturation at various temperatures and air pressures.

Testing for Dissolved Oxygen in the Field

Various types of dissolved oxygen measurement equipment are commercially available that utilize galvanic, polarographic, and optical sensors. These probes are reliable but require calibration and maintenance which may not always be cost effective for certain kinds of project specific monitoring requirements.

Test kits are a lower cost option than probes but may require multiple steps to obtain test results. Many test kits on the market today utilize an older method called the Winkler Titration. CHEMetrics offers test kits that employ the simpler but equally reliable indigo carmine method. A comparison study was conducted between CHEMetrics K-7513 Vacu-vials® and K-7512 CHEMets® test kits (indigo carmine method) and LaMotte’s 5860-01 test kit (Winkler Titration).

What is the Winkler Titration?

The Winkler Test, also referred to as the Winkler Titration or the Iodometric Method, was created by Lajos Winkler in 1888 while working on his dissertation at Budapest University. The method is broken down into a few steps that can be altered with slightly different chemicals. The first step is the fixation of oxygen in the sample. For the LaMotte 5860-01 kit, manganous sulfate, MnSO4, and an alkaline potassium iodide azide solution are added to the sample. This creates a white precipitate of manganous hydroxide, Mn(OH)2. Once the precipitate is formed, oxygen in the water oxidizes an equivalent amount of Mn(OH)2 to a brown precipitate called manganic hydroxide, Mn(OH)3. A strong acid, commonly sulfuric acid, is added to acidify the solution. The acid converts the Mn(OH)3 to manganic sulfate, Mn2(SO4)3. After this step, because the oxygen within the sample is “fixed,” additional atmospheric oxygen being introduced to the sample is unlikely to interfere with the test result. The manganic sulfate oxidizes potassium iodide to form iodine. The amount of iodine released is proportional to the amount of oxygen present in the sample. The release of iodine changes the color of the sample to a yellow-brown color. The final step is to determine the amount of iodine in the sample by titrating with sodium thiosulfate (Na2S2O3). When the iodine has been completely converted into sodium iodide (NaI) the solution will turn colorless. It is not uncommon for an indicator to be added to make the final endpoint easier to determine.

A photo of LaMotte's 5860-01 Test Kit for Dissolved Oxygen

The LaMotte 5860-01 test kit utilizes the Winkler method for Dissolved Oxygen analysis.

What is the Indigo Carmine Method?

CHEMetrics K-7512 CHEMets (visual) and K-7513 Vacu-vials (instrumental) dissolved oxygen test kits are based on the Indigo Carmine Method and self-filling ampoule technology. The indigo carmine method utilizes the reduced (or leuco) form of the indigo carmine dye which is yellow. When this form of indigo carmine reacts with oxygen, it changes from a yellow green to a blue color. The intensity of the blue color is directly proportional to the concentration of dissolved oxygen in the water sample.

CHEMetrics K-7512 Dissolved Oxygen Test kit and contents

CHEMetrics K-7512 visual test kit utilizes indigo carmine method for Dissolved Oxygen Analysis

The indigo carmine reagent is packaged inside CHEMetrics glass ampoules sealed under vacuum. The analyst snaps the ampoule tip in the water sample prompting sample to be drawn into the ampoule. When the ampoule is inverted, the bubble mixes the reagent with the sample. After a 2-minute color development time, K-7512 CHEMets ampoules are read in a color comparator where the intensity of the blue color developed in the test ampoule is visually compared against color standards representing DO concentrations ranging from 1 – 12 mg/L (ppm). Likewise, K-7513 Vacu-vials ampoules can be read in spectrophotometer at 485 nm in absorbance mode. CHEMetrics provides a calibration equation to convert absorbance to ppm DO. Alternatively, K-7513 Vacu-vials ampoules can be read in CHEMetrics pre-calibrated photometers that display direct ppm DO test results ranging from 2 – 15 ppm.

Vacu-vials® Instrumental Test Kit Contents and Packaging

CHEMetrics K-7513 Is an instrumental version of the indigo carmine method for Dissolved Oxygen analysis.

Unlike the Winkler method, the CHEMetrics indigo carmine test procedure is simple, fast and does not require measuring and adding multiple reagents to the sample to complete the required chemical reactions. Therefore, the test can easily be performed immediately at the time of sample collection, minimizing the opportunity for atmospheric oxygen to enter the sample. Furthermore, the K-7512 and K-7513 test kits are not susceptible to interferences from temperature, salinity, or dissolved gases like sulfide. The ease of this method makes it especially convenient for environmental water analysis.

Comparing Performance of Winkler and Indigo Carmine Dissolved Oxygen Test Kits

A protocol was designed to compare test results generated by the two methods. Oxygen in nitrogen gas standards representing two levels of oxygen were bubbled into a 2-liter separatory funnel containing deionized water. The concentration of dissolved oxygen was determined from the application of Henry’s Law, the barometric pressure, and water temperature. The sampling bottle provided with the LaMotte’s 5860-01 was filled with sample from the separatory funnel. This sampling technique was found to be a more reliable procedure in a lab setting than the submerged bottle method suggested by the LaMotte kit instructions. Once the LaMotte bottle was filled, the LaMotte test procedure was followed. Both the K-7512 CHEMets and the K-7513 Vacu-vials ampoules were snapped while the sample continually flowed into a beaker. A Hach DR 2800 spectrophotometer was used to measure K-7513 absorbance values. An I-2002 CHEMetrics Single Analyte Meter (SAM) was used for a second set of instrumental readings. Two DO concentrations were evaluated, 4.0 and 10.7 ppm. The results of the testing are displayed below.

CHEMetrics vs. Winkler test results

A table comparing CHEMetrics test results to Winkler test results

Results

Test results agreed favorably among the LaMotte and CHEMetrics instrumental and visual test kits. At 4.0 ppm DO, less than 1 ppm error was observed with both the Winkler and the indigo carmine methods. At 10.7 ppm DO, both methods performed similarly with errors ranging between -1.1 and 0.3 ppm DO. K-7513 test results were consistent between the spectrophotometer and I-2002 SAM photometer.

Conclusion

Measuring dissolved oxygen is critical to understanding the health of aquatic environments. There are many ways to analyze dissolved oxygen, such as probes and test kits. Many test kits offer the Winkler titration method which is labor intensive and complicated, requiring addition of multiple chemicals. CHEMetrics offers an indigo carmine method packaged in our self-filling ampoules to create a simplified testing procedure. It can be used to obtain accurate results with fewer steps and less chemical handling than with the Winkler method. The ease of use and portability of the CHEMetrics test kits and I-2002 SAM photometer make them perfect for testing in the field. To purchase CHEMetrics test kits or find more technical information about the K-7512 and K-7513 test kits, please explore our dissolved oxygen test kits.

Zachary Waszczak, July 2021

 

References

  1. EPA National Aquatic Resource Surveys Indicators Dissolved Oxygen. https://www.epa.gov/national-aquatic-resource-surveys/indicators-dissolved-oxygen (accessed Apr 12, 2021)
  2. Dissolved Oxygen (DO), Government of Northwest Territories Environment and Natural Resources. https://www.enr.gov.nt.ca/sites/enr/files/dissolved_oxygen.pdf (accessed Apr 12, 2021)
  3. LaMotte Dissolved Oxygen Water Quality Test Kit Instruction Manual Code 5860-01.

 

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