TNI Logo The NELAC Institute

Combined Interpretations of the 2003, 2009, and 2016 Standards that apply to Volume 1 of the 2016 TNI Standard


Question:  For subsection (a), I would like an interpretation of the requirement to obtain the manufacturer's Certificate of Analysis for reagents.  Does this mean just "ready-made" reagents (e.g. the color reagent for a test) or does this also include pure chemicals (e.g. a bottle of sodium chloride crystals)? 

TNI Response:  The standard requires that Certificates of Analysis be obtained for all reagents. This does not mean that the C of A is automatically supplied. In some cases, you may need to request such information from a manufacturer. This includes both "ready-made" and pure (neat) chemicals.


Question:  This section requires the lab to retain records of the standard or reagent manufacturer's Certificates of Analysis. One of our largest standard manufacturers recently stopped automatically sending hard copies of the C of A with the material, stating that it can be accessed electronically from their website. The manufacturer says an advantage of this, among other things, is "immediate accessibility for audits". My question is if hard copy of the C of A onsite at the lab is strictly required, or if access to the electronic copy "on-demand" is sufficient.

TNI Response:  The laboratory must maintain copies of the Certificates of Analysis (CoAs), whether in hard copy or electronic format, in accordance with the lab's records and document control procedures and as required by the TNI Standard. The laboratory must maintain and control all records used to document lab activities, including CoAs, and all records must be made available to the accreditation body. The laboratory must retain all records (hard copy or electronic) for a minimum of five years (V1M2, section 4.13.3), and labs must incorporate procedures to maintain CoA from manufactures that do not have the same retention schedule for electronic CoAs.


Question:  My question is about documentation and traceability of consumables.  Are environmental labs required to maintain records (i.e., Certificate of Analysis, storage, date of receipt, etc.) for such consumables as carrier gasses used for Mass Spec or Spec type instrumentation?

TNI Response: requires documentation for "standards, reagents, reference materials, and media.” Carrier gasses are not referenced within this section. However, a carrier gas is a laboratory consumable material that affects the quality of tests and is subject to the policy and procedure requirements described in 4.6.


Question:  Assuming that we have a working definition for reagents, does the word "prepared" in refer only to standards or all three (standards, reference materials and reagents)?  Assuming the latter, see the discussion below for the actual question).  Prepared reagents are readily defined as reagents that are prepared in the lab by modifying (diluting, mixing, etc.) one or more precursor reagents or standards.  However there is some ambiguity concerning the term “container.”   Suppose I make 200 ml of a reagent stock, say the Ammonium Molybdate reagent used in total phosphorus analysis that is stored in a lab refrigerator. Every time we perform a TP run, a small amount of this reagent is poured into a second container, a removable, plastic reagent well that is part of our discrete analyzer’s autosampler.  At the end of the day, this reagent is not completely used up, and to minimize waste, we cap the removable plastic well and store it in the refrigerator overnight.  It is refilled the following day for the next day’s analysis.  Since the reagent stock was prepared only once, it would be assigned a single, unique serial number.  The mere act of pouring some of this reagent into a second container should not (logically) require one to generate a second serial number.  To summarize the question, is only one unique serial number needed for each contiguous preparation, regardless of the number of containers in which the reagent might be stored?  i.e., Is this description of unique identifiers for prepared reagents consistent with the meaning and intent of (d)?

TNI Response:  The use of the reagent at analysis requires that all data necessary for the historical reconstruction of the data be available (see 4.13.3 f). Somewhere with the analytical batch, reference must be made to the unique serial number of this reagent. A new serial number need not be created due to the act of pouring the reagent from one container to another. The unique serial number is created at a point in time when the reagent, standard or material is made in the lab. If no changes are made, then a new number need not be created. The act of removing the container from its specific location on the instrument requires that the container be labeled with the reagent's unique identifier in order to comply with the traceability requirement of c.