Sample Collection is the first, and perhaps the most important step in the analytical process. Poor sampling inhibits the labs ability to produce representative data of a sampling source. Sampling is comprised of 5 main steps:
1. Create a Field Sampling Plan
2. Contact lab to order bottle kit and discuss any scheduling complications
3. Conduct sampling following instructions from Field Sampling Plan and the lab
4. Release Custody of Samples to the lab, or a third party shipper
5. Review Sample Receipt to ensure correct analyses are ordered
What do each of these steps mean? Let’s take a closer look.
1. Field Sampling Plan- This is necessary to succeed in sampling, and generally should include the following:
2. Ordering Bottles and Scheduling Sampling- Call us to order your sample containers. The bottles provided will be bagged together into “sets” to keep each site organized. A cooler will also be provided. The lab will generally need the following information:
Depending on the situation, more coordinating and information may be required! For example:
Courier Pick Up or Drop Off– If you need sample containers dropped off at your site or picked up from a courier, it is wise to plan sampling around your labs standard courier routes. You can find WETLAB’s standard courier schedule here.
Sample Shipping– If samples are being shipped to or from a remote location, consider the amount of time samples will be in transit. If you are sending short-hold samples, selecting a “next day delivery” option may be necessary.
Subcontracted Work– Most subcontracting is shipped to southern CA and NV, therefore, factor this extra time in transit when making your sample plan. Furthermore, avoid delivering samples requiring subcontracting on Fridays, as they cannot ship out until the following Monday.
Weekend Work– Weekend work is not ideal, however, it is sometimes unavoidable! It is important, however, to notify your lab as soon as possible about weekend work so that staff can be scheduled to accommodate the request.
3. Sampling- Once the game plan is set, it is time to execute your sampling project.
4. Releasing Custody of Samples- An additional responsibility of a sampler is properly documenting sample information and signing for any change of sample custody. The analytical Chain of Custody (or COC) is a required legal document submitted with samples to the laboratory. This document is a requirement for any sample submission to a lab, and serves numerous purposes:
5. Review Sample Receipt- WETLAB can send you an electronic “ sample receipt” which will list the entered information from your Chain of Custody, the receiving conditions of your samples (including anomalies), and an itemized list of all the analytical testing slated for your samples.
This is the final check before the testing will commence, so it’s important to review as soon as possible and contact the lab with any questions or concerns.
Contact WETLAB at (775)355-0202 to discuss your sampling requirements and project needs.
What is a preservative, and why is it important? According to the EPA, methods of preservation are relatively limited and are intended generally to (1) retard biological action, (2) retard hydrolysis of chemical compounds and complexes, (3) reduce volatility of constituents, and (4) reduce absorption effects.
In other words, the purpose of a preservative is to “freeze” the sample chemistry at the point of sampling so that what gets analyzed at the lab is as similar to the source as possible, despite the unavoidable delay between the sampling and analysis.
Some common preservatives include:
However, the most important, but often overlooked, preservative is ice. Keeping a sample cold (between 2-6C) is a requirement for nearly every analytical test we perform EXCEPT for metals analysis. It is generally preferable to use wet ice instead of ice packs when possible.
Sample containers, just like preservatives, are designed to inhibit the natural chemical changes which will occur in a sample as time passes. In addition to that, sample containers also serve a few other purposes:
But how do I know which sample bottle and preservative to use? Simple, you ask the lab! By contacting WETLAB before you begin your sampling process, you will help ensure that you use the correct bottle and preservative. Our staff can also help you review your permit making sure the correct samples are taken at the correct time of the year (DPBs, LCR, SOCs), and making sure the correct methods are used for your sample matrix (drinking water, waste water, haz waste). We can even help with sampling requirements making sure your samples are collected as intended by your permit (LCR first draw, grab vs. composite), saving you valuable time that can be lost from unintended mistakes.
Be aware, preservatives and hold times are dictated by the analytical method and enforced by state/federal agencies and the laboratory. Cyanide species, Volatile Organics, Dissolved Oxygen, Bacteria, SOCs, DBPs, and many other tests absolutely require correct bottles and preservatives to analyze for compliance.
Contact WETLAB at (775)355-0202 to discuss your sampling needs. Our seasoned staff can help you determine which samples you need, how they need to be collected, and provide you with all the right bottles and preservatives to make sure your procedures remain in compliance.
Arsenic is a well-known inorganic element, and it is one of the many routinely monitored contaminants in drinking water. WETLAB tests for Arsenic in drinking water through EPA Method 200.7 and 200.8. But how does Arsenic make its way into drinking water, and what are the potential health effects from increased Arsenic load?
The EPA requires that ground water systems monitor for Arsenic every three years, and surface water systems every year. These frequencies may be increased if Arsenic is found to be at or above the MCL (Maximum Contaminant Level), defined as 10ppb (parts per billion). This MCL was lowered from 50ppb in 2001 to better protect public health.
Arsenic is a naturally occurring element found in soils and rocks, and is also a by-product of several industrial and agricultural processes. Drinking water contamination can occur from naturally eroding deposits, and from runoff of various processes. Some water will be naturally higher in Arsenic due to the rocks and soils that make up the aquifer. Arsenic contamination can be treated in many ways, including Iron treatment and adsorption, which helps precipitate Arsenic out of water.
Ingesting water with Arsenic levels greater than the MCL can cause adverse health effects if the water is consumed for many years. These health effects include skin damage, circulatory problems, and an increased risk of various cancers.
To find out more about Arsenic in drinking water, visit this guide, published by the EPA.
At WETLAB, we believe that good communication is a critical part of ensuring our clients receive good data. Our QA manager and sales team presented on this topic in March at the Nevada Rural Water Association Conference in Reno, NV. Below is a small synopsis of this presentation.
Good communication appears to be a simple goal, but can be difficult to achieve. There are many players involved at every stage, and one small miscommunication can result in the end product not being what is needed. The ultimate goal is to produce legally defensible results that meet Data Quality objectives.
It is imperative that clients and the lab communicate clearly- WETLAB strives to ensure that all of our clients understand what data they need to satisfy regulatory requirements. The regulatory landscape concerning water is ever-changing, and can be confusing. At WETLAB, we stay up to date with the latest changes so that we can help our clients get the results they need. Outside of the lab, we talk to our clients and their regulators to determine needs. Inside of the lab, we discuss projects clearly throughout all departments.
The critical point of communication occurs between the client and the lab. Providing WETLAB with the appropriate documents helps to clearly show objectives. These documents include: a detailed Client Information Sheet, a Sampling Analysis Plan, the Scope of Work, and the Chain of Custody. Having an accurate and clear Chain of Custody is imperative to retain legal defensibility of sample results. Our staff reviews all Chain of Custody forms to make sure they are clear and fully completed.
If all participants communicate as clearly as possible, the goal of regulatory compliance can be achieved. Contact WETLAB to see how we can help you achieve your goals.
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.
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.
This is the final installment of our ongoing series Life of a Sample, which explores what happens behind the scenes at WETLAB. If you missed parts one through five, check them out here!
Our sample has now been received, prepped, distilled/ digested, analyzed, and entered. The final, and terminal step, is reporting. At this point, samples will have been validated, which means that QA/QC parameters have been checked to ensure they are within acceptable ranges. These parameters include checking total versus dissolved solids, Maximum Contaminant Levels (MCLs) for drinking water, cation versus anion balances, and several others. If any of these validation measures are outside of acceptable or expected limits, QA staff will determine if the sample needs to be re-analyzed. If the sample passes the validation check, the data is ready to be reported to the client and regulating agency. Our client services staff ensures that clients are provided with a complete and accurate report of all results, and they understand what they have been provided with. If the sample is being analyzed for compliance, such as drinking water for a public water system, the results are also provided to the regulating agency. After reporting is finished, our sample’s life cycle is complete!
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.
Our ongoing series Life of a Sample explores what happens behind the scenes at WETLAB. If you missed part one and two, check them out here!
The next step for a sample at WETLAB is distillation and digestion, which takes two days. Lab technicians start with organizing samples by hold times and due dates, ensuring timely and accurate analysis. Then, we look through historical data to determine if any dilutions are usually needed. All samples are then organized, the sample preparation log is meticulously filled out, and reagents and standard solutions are gathered. Then the distillation or digestion block is heated, and once the block reaches the correct temperature, the samples are added. The process is carefully watched, making sure that no samples boil over, and that the bubbles don’t stop during distillation. Once the timer stops, the samples are removed from the hot block and placed in clean specimen cups. Up next, samples move to analysis.