Frequently Asked Questions

Q: Can you test indoor air quality for my house?

There is no "one size fits all" test for sampling of potential air pollutants, as there are many different classes of chemicals and each one is sampled differently. Our air testing services are catered towards industrial and commercial clients needing testing of air samples for volatile organic compounds (VOCs) and semi-volatile organic compounds (SVOCs). This level of testing is generally cost-prohibitive for private individuals.

Your local health department may be able to refer you to a local indoor air quality specialist, certified industrial hygienist, or environmental consultant who will have the expertise of how to collect the samples and manage the testing for you.

Q: Can you test my prescription medication for contamination?

Our services are primarily for contract manufacturers, pharmaceutical/nutraceutical production, and botanical/chemical product supplier companies. The level of testing required for a single test is generally cost-prohibitive for private individuals.  You may also try contacting the U.S. FDA or your local health provider.

Q: Can you test for chemicals in blood or urine?

We generally do not offer medical testing. Our laboratories are for environmental and pharmaceutical testing, but not for medical purposes. You may try contacting your local health provider or Centers for Disease Control (CDC).

Q: Can you test to determine if someone is poisoned?

Our laboratories are for environmental and pharmaceutical testing, but not for medical testing. We suggest contacting your local health provider or poison control center.

Q: Do you have a price list?

A: We do not have an all-inclusive price list as each project is unique to your needs. Please contact us or call 1.800.695.7222 to receive a quick quote.

Q: What analyses and services do you provide?

The following is a general list of the analyses performed by ALS - Columbia. Our scientists are constantly adding to our capabilities. If you want to know about a specific analyte or group of compounds please contact us.

  • Environmental testing of air, water, wastewater, soil, sludge, solids, waste oil, solvents, hazardous waste, sediments and tissues
  • Micro-elemental analyses including those for C, H, N, O, S, metals and halogens on a wide variety of matrices
  • Process and quality control testing for many industries including pulp and paper, electronics, pharmaceutical and nutraceutical industries
  • Analytical method development
  • Sampling, field and mobile laboratory services
  • Technical consulting
  • Program management
  • Data management

Q: What is NELAP/NELAC certification?

In 2006, the Boards of the National Environmental Laboratory Accreditation Conference (NELAC) and the Institute for National Environmental Laboratory Accreditation (INELA) took action to form The NELAC Institute to oversee a national environmental laboratory accreditation program. Though many states in the US are now members and allow analyses on samples from their states by NELAP accredited laboratories, there are still some states that have preserved their own certification programs.

Q: What analytical method should I request?

The proper analytical method for your situation depends on what regulatory act or agency requires the testing. Testing generally falls under one of the following:

  • Clean Water Act (CWA): for rivers, oceans, wastewater (aka NPDES or National Pollution Discharge Elimination System), and stormwater: Methods for Chemical Analysis of Water and Wastes (MCAWW): methods are numbered between 100 and 400s or in the 600s.
  • Safe Drinking Water Act: for potable water evaluation: methods are numbered between 100 and 400s or in the 500s.
  • Resource Conservation and Recovery Act (RCRA): created a framework for the proper management of hazardous and non-hazardous solid waste and includes 3 programs.
    • The solid waste program concerning disposal in landfills or other solid water disposal facilities and prevents open dumping of solid waste.
    • The hazardous waste program which controls hazardous waste from creations to ultimate disposal.
    • The underground storage tank program which controls underground storage tanks which may contain petroleum products or other hazardous substances.
    • Methods are labeled SW 846 methods and are numbered in the 1000s, 3000s and the 5000s to 9000s.
  • Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) aka Superfund governs the cleanup of abandoned or uncontrolled hazardous waste sites. These sites are generally under EPA oversight and they determine the analytical methods to use.

There are other agencies that may require specific methods. Please contact us if you have questions.

Q: What are field quality control samples?

These are samples that are taken to ascertain whether anything that happened in the field might have affected the analytical results and that nothing about the sample itself would affect the analytical results. They consist of:

  • Trip Blank: accompanies the samples to and from the field, never opened, until all samples are readied for analysis. Its purpose is to assess the potential for in-transit contamination of samples.
  • Field Blank: exposed to the same field conditions as the sample, opened in the field. Its purpose is to assess the potential for field contamination.
  • Equipment Blank: rinsate from the equipment used to take the sample. The purpose of the equipment blank is to assess the potential of cross contamination of samples due to insufficient decontamination of sampling equipment
  • Field Duplicate: a duplicate sample taken in the field from the same location as the original sample to ascertain sampling precision.
  • Blind Duplicate or Double-Blind PE: same as the field duplicate above, but it is given another name so it’s not identified with any field duplicate, again to test precision
  • Split Samples: sample is split and sent to 2 or more laboratories for the same test. They are used to assess the analytical precision between the laboratories.
  • Temperature Blank: a vial of water that accompanies the samples that will be opened and tested upon arrival at the laboratory to ensure that the temperature of the contents of the sampling shipping container was within the required 4°C ± 2°.

Q: What are laboratory quality control samples?

These are samples that are taken to ascertain whether anything that happened in the field might have affected the analytical results and that nothing about the sample itself would affect the analytical results. They consist of:

  • Method Blank (MB): an analyte-free matrix (water, soil, etc.) subjected to the entire analytical process to demonstrate that the analytical system itself does not introduce contamination. The method blank results should be below the Method Reporting Limit (MRL) or, if required for DoD projects, < ½ MRL for the analytes being tested. A method blank is included with the analysis of every sample preparation batch, every 20 samples, or as stated in the method, whichever is more frequent.
  • Matrix Spike/Matrix Spike Duplicate: a known amount of a compound similar chemically to the target analyte is added to samples to ascertain any matrix effects on recoveries and to determine the accuracy and precision of the method in this matrix.
  • Laboratory Control Sample (LCS): a well-characterized sample of known analytes and concentration. A reference material containing certified amounts of target analytes, may be used as an LCS. An LCS is prepared and analyzed at a minimum frequency of one per 20 samples, with every analytical batch or as stated in the method, whichever is more frequent. The LCS sample is prepared and analyzed in exactly the same manner as the field samples. The percent recovery of the target analytes in the LCS is compared to established control limits and assists in determining whether the methodology is in control and whether the laboratory is capable of making accurate and precise measurements at the required reporting limit. Comparison of batch-to-batch LCS analyses enables the laboratory to evaluate batch-to-batch precision and accuracy.
  • Surrogates are organic compounds that are similar in chemical composition and behavior to the analytes of interest, but are not normally found in environmental samples. Depending on the analytical method, one or more of these compounds is added to method blanks, calibration and check standards, and samples prior to extraction and analysis. Samples include duplicates, matrix spike samples, duplicate matrix spike samples and laboratory control samples. This is done in order to monitor the method performance on each sample. The percent recovery is calculated for each surrogate, and the recovery is a measurement of the overall method performance.
  • Post Digestion Spike or Post Spike: Post digestion spikes are samples prepared for metals analyses that have an analyte spike added to determine if matrix effects may be a factor in the results. The spike addition should produce a method-specified minimum concentration above the method reporting limit. A post digestion spike is analyzed with each batch of samples and recovery criteria are specified for each method.
  • Initial (or independent) calibration verification standards (ICVs) are standards that are analyzed after calibration with newly prepared standards but prior to sample analysis, in order to verify the validity and accuracy of the standards used in the calibration. Once it is determined that there is not a reference material defect or systematic error in preparation of the calibration standards, the newly prepared standards are considered valid and may be used for subsequent calibrations and quantitative determinations (as expiration dates and methods allow). The ICV standards are prepared from materials obtained from a source independent from the one used for preparing the calibration standards (“second-source”). ICVs are also analyzed in accordance with method-specific requirements.
  • Continuing calibration verification standards (CCVs) are midrange standards that are analyzed in order to verify that the calibration of the analytical system is still acceptable. The frequency of CCV analysis is either once every ten samples, or as indicated in the method.

Q: What are the different reporting units?

  • Wet Weight (as received) basis: Concentration of the analytes reported based on the sample’s wet weight or as received condition.
  • Dry Weight basis: The concentration is adjusted to remove the moisture from the sample.
  • Percent: parts per hundred
  • PPM: parts per million
    • mg/L: weight/volume
    • mg/Kg: weight/weight
  • PPB: parts per billion
    • µg/L: weight/volume
    • µg/Kg: weight/weight
  • PPBv or µL/L: volume/volume – air analyses - this does NOT equal µg/L.

Q: What is your turn around time?

All ALS - Columbia laboratories strive for a standard turn around time of 14 days, however there are many factors affecting this, such as the current laboratory capacity, when the samples arrive, and reporting requirements needed, among others. Contact us to learn what turn around times are available.

Q:. What are MDLs and MRLs?

MDL = Method Detection Limit

MRL = Method Reporting Limit

Contact us for current MDLs and MRLs.

Q:. What data “flags” (or qualifiers) do you use and what do they mean?


  • Data Qualifiers which are related to the sample matrix
    • “i” for interference means the MRL/MDL has been elevated due to a chromatographic interference. The presence of certain components in the sample matrix have compromised the ability to detect and/or quantify target analytes.
    • “d” for dilution means the sample has been diluted or less sample used to improve the ability to detect and quantify either one or more analytes or the whole chromatogram.
  • Concentration Qualifiers which are related to the concentrations
    • “U” or “ND”: the compound or analyte was not detected at or above the MRL/MDL using the prescribed analytical method.
    • “J” ( for organics) or “B”( for inorganics): the compound or analyte was detected below the MRL but above or equal to the MDL. So there is a likelihood the compound or analyte may be there but quantification is not possible as it was detected below the lowest calibration point.
    • “B” for organics: the analyte or compound was found in the associated method blank at a level above the MRL for DoD projects “B” is used if the level is ½ the MRL. This indicates inaccuracy with the sample result or maybe a false positive result. “B” is not typically used if the sample concentration is significantly higher than the level found in the method blank (i.e. 20 times greater)
    • “E”: the result is an estimate because the analyte concentration exceeded the upper instrument calibration range. The estimate accuracy may vary widely depending on the calibration range, the analyte and the detector.
  • Procedural Qualifiers which are related to deviations from the method or standard operating procedure of the laboratory
    • “P” means the gas chromatograph or high performance liquid chromatography confirmation criteria was exceeded. The relative percent difference was greater than 40% and less than 100% between the 2 analytical results (25% for pesticides under the EPA’s contract laboratory program protocols. This applies only to dual column analytical methods that do not produce additional qualitative data. It may mean that interference exists on one of the columns. If that can be verified on one of the columns, the result from the other column is reported. If no interferences can be identified, the higher of the two results is reported. Confirmation results with greater than 100% relative percent difference result in an “i” flag on the lower concentration.