In our blog posts Lessons From the Lab we answer frequently asked questions from clients.  Find all installments of Lessons From the Lab here. 

What is Trace Metals Analysis?

Trace Metals analysis may be performed on a variety of aqueous matrices. Depending on the objective of your sampling, WETLAB can perform total recoverable or dissolved metals analysis. For total recoverable or total metals analysis, the sample must be preserved with the addition of nitric acid (HNO₃) to lower the pH of the sample to <2. Dissolved metals require an additional step prior to the addition of HNO₃. Samples for dissolved metals must be filtered using a 0.45 µm filter, after the sample has passed through the filter, the sample must be preserved with HNO₃. In SW-846, the EPA recommends that samples are field filtered. If field filtration is not possible, clients may submit an unpreserved sample to WETLAB and we can filter the sample using 0.45 µm filters and preserve with HNO₃. If field preservation is not possible, the EPA recommends in EPA 200.2, “Preservation may be done at the time of sample collection, however, to avoid the hazards of strong acids in the field, transport restrictions, and possible contamination it is recommended that the samples be returned to the laboratory within two weeks of collection and acid preserved upon receipt in the laboratory. Following acidification, the sample should be mixed and held for 16 hours.” Aqueous samples that have been properly preserved for trace metals analysis by EPA 200.7 and/or EPA 200.8 may be held and analyzed up to six months after collection date.

 

 

In our blog posts Lessons From the Lab we answer frequently asked questions from clients.  Find all installments of Lessons From the Lab here. 

What is a Reporting Limit?

A Reporting Limit (RL) is defined as the smallest concentration of a chemical that can be reported by a laboratory. If a laboratory is unable to detect a chemical in a sample, it does not necessarily mean that the chemical is absent from the sample altogether. It could be that the chemical concentration in the sample is below the sensitivity of the testing instrument. Concentrations below the RL are reported as not detectable at the RL or “less than” the RL. The RL value is often defined be each specific laboratory, so it is not uncommon to come across different RL’s when testing the same compound. RL’s act as safety protocols that allow laboratories to efficiently communicate the different variables correlated with testing and analyzing samples from a wide variety of sources and factors. It is important to identify the limit of concern that the client has when testing their sample to ensure that the RL is less than the regulatory limit. That enables a laboratory to identify whether a concentration of the chemical in question is above the regulatory limit of concern.

WETLAB is a certified lab for drinking water testing in Nevada, with reciprocity for testing in California, Wyoming, and Idaho.  This means that when you send drinking water samples to WETLAB, we guarantee thorough, high-quality data that complies with regulatory standards.  We ensure that your sample is analyzed with up-to-date methods, performed with the precision and attention to detail that you require.  We analyze drinking water for regulated public water systems of all sizes and for private domestic wells.

Private domestic well owners face a unique set of circumstances not often realized by many people who utilize a community water system.  Well owners are responsible for ensuring their own water quality, which means regular water testing.  Your water can contain microscopic particulates and micro-organisms that you would be unable to detect with your naked eye.  The Environmental Protection Agency recommends testing your well regularly for several contaminants, including total coliform, pH, corrosion, nitrates, and metals.  If you experience any changes in water quality, such as rapid corrosion of pipes, undesirable tastes or smells, or increased scaly build-up, you may be interested in testing your water quality.

If you are interested in testing your private domestic well, reference this helpful guide from the UNR Cooperative Extension.  This guide will help you determine what drinking water parameters you may be interested in testing for, and what the critical limits for some contaminants are.  After you test your water, you can use this tool to help interpret your results.  Our friendly staff at WETLAB will be happy to assist you with any other questions you might have.

WETLAB provides a uniquely client-oriented lab experience that will ensure you obtain the quality lab results you seek.  Contact WETLAB at (775) 355-0202 to determine how we can help you.

Our ongoing series Life of a Sample explores what happens behind the scenes at WETLAB.  If you missed parts one through four, check them out here!

At this point in our sample’s life cycle, the sample has been received, prepped, distilled/ digested, and analyzed.  The next step is entering all the collected data so that it can be transmitted to clients.  During this step, all the raw data is double-checked for inaccuracies and to ensure that all quality control samples have been included.  All data that can’t be migrated digitally is hand-entered by lab technicians, which is then checked for input errors such as incorrect dates or mis-typed numbers.  Catching these small errors is critical for ensuring data is reported correctly and on time for our clients.  This step is typically completed by the end of the day the sample finishes analysis.  After data entry, our sample will reach its terminal stage- reporting.

Lithium Brine Testing- Methods for Analysis

In part one of this two part series, we provided an overview of WETLAB’s industry leading practices for Lithium Brine Testing. In part two, we will explore the strengths and limitations associated with each of the four testing methods, including ICP-OES- the preferred method of brine characterization.

WETLAB is an industry leader for lithium brine testing, and has excelled at characterization using ICP-OES. The four main methods of lithium brine testing each have its own strengths and limitations, which we explore below.

FAAS (Flame Atomic Absorption Spectroscopy) involves a nebulized sample being passed through an acetylene flame and the light absorbance of a specific wavelength is then measured. Some of the potential limitations involved with FAAS characterization include low sensitivity, relatively low ionization temperature (3000°C), and only one analyte can be run at a time. Phosphates and Sulfates can also form flame-stable metal salts, which can complicate analysis.

GFAAS (Graphite Furnace Atomic Absorption Spectroscopy) involves the sample being heated in a graphite tube, and then atomized light is passed through the tube and measured at a specific wavelength. Due to heating programming and specificity, GFAAS analyses are typically done for one element at a time. GFAAS also has long sampling times, low temperature, and a limited dynamic range.

ICP-MS (Inductively Coupled Plasma – Mass Spectrometry) involves a nebulized sample being passed through high temperature plasma to ionize atoms, which are then isolated by their mass/charge ratio and detected directly. ICP-MS can be an excellent option for some clients, but some of the limitations for lithium analysis are that lithium is very light and can be excluded by heavier atoms, and analysis is typically limited to <0.2% dissolved solids, which means that it is not great for brines. Equipment and technician training costs are also very high with this method.

ICP-OES (Inductively Coupled Plasma – Optical Emission Spectroscopy) involves a nebulized sample being passed through high temperature plasma to ionize atoms, which release light at specific wavelengths. This is the preferred analytical technique for most metals in any matrix, and all metals in a complex matrix such as brine solutions. ICP-OES can handle a high amount of dissolved solids, has little chemical interference, and has robust sample introduction with high-energy plasma (~10,000°C) plasma. ICP-OES can also perform multi-element analysis, easily determining concentrations of other metals (K, Mg, B, etc).   Although ICP-OES is the preferred technique, it does have some limitations. These include moderate detection limits, typically lower than FAAS but higher than GFAAS and ICP-MS in a clean matrix. Complex matrices (such as brine) can often require dilutions from the other methods that may raise the overall Detection Limit. Also, spectral Interferences are common, but can typically be easily compensated to eliminate.

 

To determine how WETLAB can help you get the data you need with our industry leading practices, call WETLAB at (775) 355-0202 and speak with someone from our highly skilled customer and sample management team.

 

Our ongoing series Life of a Sample explores what happens behind the scenes at WETLAB.  If you missed part one, two, or three, check them out here!

The next step for our samples life cycle is analysis, which takes around four days, depending on the method.  Analysis starts with batch prepping the samples and preparing the instrument.  All daily required instrument maintenance is also preformed during this step.  All reagents and standards are logged here, and will later be used to monitor for QA/QC and determine accuracy.  When the batches and machines are prepped, the samples are run through analysis.  During this time, all quality control samples are monitored to ensure that the machines are functioning properly and there are no problems with analysis.  If any issues or unexpected results appear, analysts will trouble shoot all instruments and samples.  Samples that do not meet acceptance criteria are then re-run.  Potential problems can arise when samples have complicated matrices, which can cause equipment malfunctions. Once our samples are done in the analysis stage, it’s on to data entry.

Matt Weikel, Inorganic Laboratory Manager, presented at a training hosted by Nevada Water Resources Association (NWRA) regarding WETLAB’s industry leading lithium brine testing methods. In this two part series, we will provide an overview of this presentation, and explore various methods of analysis.

Lithium Brine extraction and processing is gaining traction in Nevada. Lithium mining uses evaporation ponds, which produces a brine that lithium is then extracted from. With lithium brine gaining popularity, lithium brine testing has become an interesting and ever-changing topic.

WETLAB has always sought to develop products and practices that are in our clients’ best interest, which is why we have perfected the ideal method of lithium brine testing to meet various client needs.   Lithium brine can be characterized on four different pieces of equipment, including:

1. FAAS (Flame Atomic Absorption Spectroscopy)
2. GFAAS (Graphite Furnace AAS)
3. ICP-MS (Inductively Coupled Plasma – Mass Spectrometry)
4. ICP-OES (Inductively Coupled Plasma – Optical Emission Spectroscopy)

WETLAB continues to excel at ICP-OES characterization, which is the preferred method of analysis for lithium brines.  Each of these methods has its own strengths and limitations, and is coupled with a digestion method to place the metals into solution. WETLAB commonly uses a two-acid digestion, HNO3 + HCl, which include EPA methods 200.2, 3010, and 3050. After the sample is digested, it is ready for analysis.  WETLAB commonly recommends using ICP-OES analysis, as it works best for the characteristics of brine, and obtaining other data metrics from the sample.

When you choose WETLAB for your lithium brine testing and characterization needs, you get a lot of benefits.   WETLAB prioritizes customer service and accurate analysis, and we’re always here to help you get what you want.   We ensure precise analysis through a robust QA/QC program coupled with several measures of internal data and accuracy checks.

Part two of this series, WETLAB Lithium Brine Testing, we will explore the strengths and limitations associated with each of the above testing methods, and determine why using WETLAB for ICP-OES analysis is ideal.

Bruce Metals, Inc. has been a WETLAB client since mid-2012.  BMI is an interesting client because of their project and the way that we process their samples.  Many clients have fairly standard tests, especially those that are dictated by the state in permits.  Bruce Metals is different; WETLAB worked with them to develop tests that meet their unique matrices and concentrations.  Due to the uniqueness of working with Bruce Metals, we decided to highlight them in a client testimonial.

BMI works with several mining clients to draw metals in parts-per-billion ranges from leaching solutions.  This specialized process requires specialized testing, which is where WETLAB comes in.  We have worked with BMI to make testing procedures and data that meets their needs, ensuring a long and prosperous relationship.

If you missed our client testimonial with Andy Roberts of Bruce Metals, Inc., check it out here.

WETLAB is an analytical facility, so our area of expertise lies in our ability to achieve accurate results with relatively low reporting limits for difficult matrices such as brine solutions. In the past year, WETLAB has seen an increase in the submission of brine solutions for lithium analysis. WETLAB partners with consulting firms, soils, and geochemistry laboratories to provide a complete and precise set of data, with each team contributing from their strengths. Through analysis we’ve gained valuable knowledge and experience and have developed best practices to best analyze this difficult matrix.

As far as analytical difficulties with this matrix, there are several:

• Li is a very light element. This precludes it from some testing methods outright (such as XRF/XRD).
• When Li is in a matrix with a large number of heavier elements, it tends to be pushed around and selectively excluded due to its low mass. This provides challenges when using Mass Spectrometry.
• A brine matrix also has the potential for much greater interferences regardless of method used.

At WETLAB, we have handled many Li Brine solutions and extracts, which has given us a chance to gain experience and fine tune our methodologies to meet our clients’ needs. By using different phase-testing and isolation techniques, we are able to provide a good overall picture of the complete sample in situ. We have often tested the solid, aqueous, and slurry components individually from single samples to provide a fuller understanding of the mineralogy present.

Our low reporting limits allow us to complete the analytical process with a smaller initial sample size which saves time and cost when it comes to extractions and shipping. We are also able to do larger dilutions to eliminate or reduce interferences while further reducing native sample consumption.

We have the use of a full laboratory at our disposal, with staff experienced with difficult matrices and samples with high potential for interference. This allows us to provide other analytes with good accuracy and relatively low reporting limits. The complete profile can allow field specialists to determine the appropriate steps to drive their operation with less guess-work. For instance, we were able to provide quick and meaningful results for Iron and Phosphate for a client who suspected their Lithium was in a Lithium Ferrous Phosphate.

We are always happy to field any analytical-related questions at any time.

After a heavy rainfall, water runs off of non-absorbent surfaces like roads, driveways, and parking lots. While the rain pours off the pavement, it carries away all of the pollutants with it, including oil, gasoline, and sediment. These pollutants flow with the water into natural rivers, streams, and lakes. However, it’s not only the larger waterways that are affected; drainage ditches and storm water retention ponds become polluted as well. This runoff is referred to as nonpoint source pollution because it does not stem from one specific source such as an industrial facility. Due to the lack of rainfall in Nevada’s arid climate, several months of pollutants can be released during one large storm event. Characterizing the levels of pollutants in water runoff is an important task in protecting our water sources.

WETLAB has developed specialized testing suites for characterizing this runoff. These tests include turbidity, to measure the amount of sediment that has escaped the roadways, and metal levels, including lead and mercury. To find out how WETLAB can help you characterize water runoff, call us at (775) 355-0202 and talk to one of our talented project managers.

To find out more about nonpoint source pollution, visit the Nevada Division of Environmental Protection (NDEP) website here.