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Frequently Asked Questions

General FAQs—Laboratory Services

WQCF’s state-of-the-art laboratory provides chemical characterization of aqueous samples. Currently, WQCF can analyze for the following parameters:

  • Total dissolved metals by ICPOES (inductively-coupled plasma optical emission spectrometry)
  • Total dissolved ions (anions and cations) by IC (ion chromatography)
  • Dissolved carbon (total, inorganic, or organic) by TDCA (thermal decomposition carbon analysis)
  • Total dissolved nitrogen by PCNA (photo-catalytic decomposition nitrogen analysis)
  • Total suspended solids (TSS) and Total dissolved solids (TDS)
  • Wet chemistry: Alkalinity (ALK) or Acid-Neutralization Capacity (ANC), pH, conductivity
  • Hot Acidity (HA) for mine drainage characterization

The WQCF also provides the following support functions:

  • Hot plate digestion (liquids)
  • Instrument operation training
  • Mentoring/consulting: data quality objectives (DQO); experiment/research design; good laboratory practice and safety

We recommend contacting WQCF Lab Manager Adrian Gonzalez very early in your program’s timeline, even during project development/planning. Coordination and discussion of analytical needs early in the process could uncover limitations or beneficial analytical capabilities to your overall objectives. Information learned from these discussions could impact the feasibility, objectives, direction, or progress of your project.

Topics to discuss with the WQCF lab manager include (but not limited to) the following:

  • Understand available WQCF services, capabilities, methods
  • Project Data Quality Objectives (DQO) requirement: detection limit requirements, speciation vs. total, digestion matrix composition requirements, concentration units, PARCC parameters, etc.
  • Analytical quality assurance (QA) / quality control (QC) requirements
  • Schedule logistics (when to submit samples, turnaround time requirements)
  • Account to be charged, price/cost estimates
  • Results reporting format and delivery method

Submit your samples in water-tight containers (e.g., vials) that are clearly labeled. Physically bring your secured samples to the Science and Engineering Research Facility (SERF) Room 317, on the campus of University of Tennessee, Knoxville. With your secured samples, bring a completed Request for Services (RFS) form. List your samples’ alpha-numeric identification codes (IDs) in the order to be analyzed. Please also remember to record the appropriate charge account number or payment source(s) on the RFS. At the WQCF lab, you will sign-over custody of your samples to the lab manager (unless analyzed by your qualified trained representative).

QA/QC is a critical part of all chemical analyses. The appropriate QA/QC level is 100% dependent on your job’s data quality objectives (DQO) and data end-use (e.g., application; purpose) of the results. Thus, there is a wide range of QA/QC levels to apply to any given job. It can range from a minimum of calibration standards and at least one instrument blanks to full accreditation-level QA/QC programs that include numerous calibration standards, calibration verification standards, instrument blanks, method blanks, field duplicates, laboratory duplicates, matrix spikes, QA reference standard solutions, etc. Discuss this with the lab manager before submitting a job.

There are several types of detection limits (DLs), including instrument DL (IDL), method DL (MDL), and limits of quantitation (LOQ). By accreditation requirements, WQCF performs annual method MDL studies for all instruments. This means MDLs can change slightly year-to-year. However, the LOQ is an assigned value (greater than the MDL) that the lab is highly confident in measuring accurately consistently. WQCF generally has defined its LOQ at 0.1 mg/L for most analytes. Discuss current LOQs with the Lab Manager.

Your samples are stored in the WQCF lab in a secured refrigerator until analysis. The lab manager keeps strict control of access to the lab (samples and standards; instruments and equipment). If a technical issue is identified with your samples prior to analysis, the lab manager can suspend work on your job and contact you. What happens next will depend on the outcome of those discussions.

You and the lab manager should agree on how you want results reported back to you. Typically, each instrument exports final results to an electronic file. The lab manager consolidates results from all instruments into one electronic spreadsheet file for your job. At a minimum, you can ask to receive this basic summary spreadsheet as your job report. More detailed report formats might involve labor charges for time spent preparing custom reports. In all cases, you will receive your job report after the job has been processed by our department’s business manager.

Yes. WQCF provides training on operating the ICPOES, IC, and carbon/nitrogen analyzer (CNA) located in the lab. WQCF charges an hourly rate for training. View WQCF website for current rates. Training per instrument usually consists of two sessions (different days) of approximately 3-4 hours per session. The first day consists of introduction to the WQCF’s lab facilities and instrument function, available methods and configurations of the instrument, and analytical theory. The lab manager demonstrates operation while the trainee takes notes and asks questions. The second day consists of the trainee operating the instrument as the lab manager observes and guides as needed. The trainee is documented as proficient on an instrument when one or more known-concentration reference standards are analyzed, and the trainee’s results match the expected values. A qualified, trained analyst is given access to the lab only after coordinating instrument schedule/availability with the lab manager. Samples analyzed by a qualified, trained analyst will be charged the “self-serve” price, available on the WQCF website.

ICPOES FAQs—Dissolved Metals Analysis

The following elements can be analyzed by the WQCF instrument. Asterisks indicate the most common elements analyzed by WQCF.

Group 1 and 2: Lithium, sodium*, potassium*, rubidium, cesium; beryllium, magnesium*, calcium*, strontium, barium

Transition metals: scandium, titanium, vanadium*, chromium*, manganese*, iron*, cobalt*, nickel*, copper*, zinc*; yttrium*, zirconium, niobium, molybdenum, ruthenium, rhodium, palladium, silver, cadmium*; hafnium, tantalum, tungsten, rhenium, osmium, iridium, platinum

Group 13: boron*, aluminum*, gallium, indium, thallium*

Groups 14–17: silicon*, germanium, tin, lead*; phosphorus, arsenic*, antimony*, bismuth; sulfur, selenium*, tellurium, iodine

Samples absolutely must not contain hydroFLUORIC acid (HF).

All samples must be filtered through 0.45 um filter pore size.

All samples should be acidified to pH < 2 (preferably with trace-metal grade nitric acid). That pH is attained with at least 1% (by volume) acid in the sample.

You must provide at least 10 mL of each aqueous sample. A convenient vial for submitting ICPOES samples is the Falcon(R) 15-mL centrifuge vials. Label each sample vial clearly and submit in a vial rack.

Concentrations measured are restricted to the calibration standards’ concentration range. For some elements, ICPOES offers excellent linearity over a wide concentration range. For others, the internal physics of thermal ionization and photon emission limits the linearity response and results in non-linear response by the instrument detector. Calibration standard concentrations ranging from 0.1 mg/L to 20 mg/L are typical. Custom calibration ranges can be prepared as needed. For best accuracy, samples with concentrations that exceed the calibration standard range should be diluted with a metal-free diluent and reanalyzed.

Ion Chromatography (IC) FAQs—Dissolved Ions Analysis

Currently, the WQCF lab’s IC is configured to analyze the following:

  • anions (fluoride, chloride, bromide, nitrate, nitrite, sulfate, and phosphate)
  • cations (ammonium, sodium, potassium, magnesium, calcium).

All samples must be filtered through 0.45 um filter pore size

Samples to be analyzed for mineral ions (e.g., chloride, fluoride, bromide, sulfate) do not need to be preserved. EPA recommends specific preservation procedures for samples to be analyzed for ortho-phosphate or nitrate/nitrite. Discuss this with the lab manager before submitting a job.

Provide at least 2 mL of each aqueous sample in a plastic chromatography vial. Label each sample vial clearly and submit in a vial rack.

Concentrations measured are restricted to the calibration standards’ concentration range. For some ions, IC offers excellent linearity over a wide concentration range. For others, interactions between eluent chemistry (e.g., pH) and ion structure causes substantial non-linear response by the instrument detector. Calibration standard concentrations ranging from 0.1 mg/L to 20 mg/L are typical. Custom calibration ranges can be prepared as needed. For best accuracy, samples with concentrations that exceed the calibration standard range should be diluted with ion-free water and reanalyzed.

C/N Elemental Analysis (C/NEA) FAQs—Dissolved Carbon or Dissolved Nitrogen

Currently, the WQCF lab’s CNEA is configured to analyze the following:

  • Dissolved carbon (total carbon, inorganic carbon, [by difference] organic carbon)
  • Dissolved nitrogen (total nitrogen, organic and inorganic forms combined)

All samples must be filtered through 0.45 um filter pore size.

Samples to be analyzed for inorganic carbon (e.g., carbonates) should not be acidified. For samples to be analyzed for organic carbon only, EPA recommends specific preservation procedures to minimize bacterial growth and alteration of the sample’s integrity. Discuss this with the Lab Manager before submitting a job.

Provide at least 50 mL of each aqueous sample in a glass vial. Label each sample vial clearly and submit in a vial rack. Plastic vials should be avoided for carbon analysis because it’s possible they could contribute or remove dissolved carbon species to samples, altering the sample’s integrity.

Concentrations measured are restricted to the calibration standards’ concentration range. C/N Elemental Analysis offers excellent linearity over a wide concentration range. Calibration standard concentrations ranging from 0.1 mg/L to 50 mg/L are typical. Custom calibration ranges can be prepared as needed. For best accuracy, samples with concentrations that exceed the calibration standard range should be diluted with ion-free water and reanalyzed.