Instrumental Analysis

R.D. Laboratories maintains a large inventory of modern analytical instrumentation to remain current with all compendia requirements.  We evaluate a broad range of characteristics using advanced instrumental analyses, from measuring low levels of impurities in raw materials to determining the strength and purity of finished dosage forms.

Our instruments and methods employ the most up-to-date innovations in technology and automation to perform analyses more efficiently and accurately.  Frequently, modern instrumental analysis is the only way to accomplish assay determination of finished products.

Liquid Chromatography

One of the most powerful and useful techniques in pharmaceutical analysis, R.D. Laboratories offers a wide variety of HPLC capabilities.  We assay both APIs and finished products with this type of testing, and examine peak purity, impurities and degradation products during stability and validation studies.  Detectors we use include UV (Ultraviolet), Vis (Visible), RI (Refractive Index) and PDA (Photo Diode Array).  We can deploy a nearly limitless combination of columns, mobile phases, gradients and detectors to separate and quantitate analytes.  Our refrigerated, sealed auto-samplers are ideal for thermally labile and/or photo-sensitive samples.

Gas Chromatography

R.D. Laboratories, Inc. has an extensive array of GC capabilities. Because of our extensive experience and capabilities, customers rely on us for all of their compedial residual solvents testing, client specific methods and residual solvent validations.  We have several systems that accommodate packed (glass and metal), capillary and megabore columns; and we offer a limitless variety of column types, packings and liquid phase coatings. R.D. Laboratories also deploys both FID (Flame-Ionization Detector) and TCD (Thermal Conductivity Detector) to test nearly all required compendial GC products. Direct injection and headspace auto injectors with temperature control enable us to quickly deliver extremely accurate results.

Residual Solvents

Residual solvents represent nearly 95% of GC testing at R.D. Laboratories.  Previously referred to as organic volatile impurities (OVIs), residual solvents are trace level chemical residues that are used or produced in the manufacture of drug substances and excipients or in the preparation of drug products. They can also be byproducts formed during packaging and storage of the drug product.

Our analysts have extensive experience in optimizing gas chromatographic methods and analyzing volatile organic compounds in a variety of matrices.  We have multiple gas chromatographs with a variety of injection and detection techniques.  All equipment is fully validated (IQ/OQ/PQ) and system suitability is performed using traceable reference standard residual solvent solutions to satisfy current Good Manufacturing Practice regulations.

Elemental Analysis

Metal impurities are introduced into pharmaceutical products and dietary supplements from raw materials, catalysts, equipment and the environment. World regulatory agencies are working to finalize limits for elemental impurities based on their potential toxicity (ICH Q3D and USP <232>). 

R.D. Laboratories has significant expertise and a variety of specialized equipment to assist with inorganic impurity testing.

AA, GFAA and Hydride Generator

We routinely use the GBC Avanta atomic absorption spectrometer for very specific and quantitative analysis for a variety of elements.  Flame vaporization, hydride generation, cold vapor, and electrothermal atomization methods provide parts-per-billion level detection.  We use a hydride generator for the determination of mercury by cold vapor and analysis of arsenic, selenium and other hydride forming elements. Our GBC GF3000 graphite furnace performs extremely sensitive trace elemental analyses of elements other than those measurable by cold vapor.


 The current Heavy Metals test USP <231> lacks specificity and the ability to accurately quantify individual inorganic impurities. The USP is abandoning this subjective wet chemical method in favor of a sophisticated quantitative instrumental technique.  Elemental Impurities (USP<233>) proposes the use of Inductively Coupled Plasma with Optical Emission Spectroscopy (ICP-OES) or Mass Spectrometry (ICP-MS). The USP is expected to require metal testing utilizing these techniques in January 2018.

R.D. Laboratories believes that the ICP-MS offers significant sensitivity advantages over ICP-OES and has qualified a Thermo Scientific X SERIES 2 ICP-MS.  This system offers accurate multi element determinations to part-per-billion levels with a wide linear range. For samples that are not easily solubilized we utilize a CEM Discover SP-D closed-vessel microwave digestion system.  The ICP-MS system couples to chromatographic or electrophoretic equipment if speciation is required.


This empirical test measures the dissolution of an active ingredient in a specified medium, with a given apparatus, over a specific time period. This may be a one point measurement or multi-point timed-release determination.

R.D. Laboratories performs dissolution on a wide range of finished dosage forms, although our customers most frequently request us to analyze tablets and capsules.  We commonly use Apparatus 1 (Basket) and Apparatus 2 (Paddle). We typically perform analyses of the predetermined sample intervals using HPLC, UV-VIS Spectrophotometry, AA or sometimes GC. Dissolution testing is critical in determining that active drugs have been released from the dosage form.

Water Determination

R.D. Laboratories uses two types of autotitrator instruments to perform water determinations (USP chapter  <921>, Type I).  These are the Mettler-Toledo V20 for 0.01% – 100% water content determinations, and the KEM MKC-510 for trace level determinations.


RD Laboratories uses the Mettler-Toledo V20 Karl Fisher autotitrator for water determinations where the expected water content is between 0.01 % to 100% of the sample.  The V20 is a dedicated volumetric KF titration system capable of using titrants corresponding to 2 mg water per mL of titrant and 5 mg water per mL of titrant.  The sample is introduced directly into the desiccated vessel through a sample port, dissolved or dispersed, and titrated to the potentiometric endpoint.  The system utilizes a stepping-motor driven auto-fill burette capable of 20,000 steps at a resolution of 0.25 microliters of titrant delivered.


For trace water determinations R.D. Laboratories uses the KEM MKC-510 Karl Fischer coulometer with an ADP-511 evaporator. This apparatus performs Karl Fischer water determinations at extremely low levels and without interferences seen in traditional Karl Fischer determinations. This auto electronic titrator consists of a closed system, purged with a dry inert gas. A specific temperature program, complete with gradients and holds, expels moisture from the sample which is contained in a glass boat, isolated from the titration vessel. As the moisture is swept into the cell reagent, the titration is conducted using electrodes, measuring water at the microgram level.


R.D. Laboratories’ osmometer determines the concentration of a solution by determining the solution’s freezing point, which is directly correlated to the level of the concentration. Freezing point osmometers are superior other instruments, like vapor pressure osmometers, because other instruments can miss certain volatilities that may be present in the solution, such as carbon dioxide, ammonia and alcohol.

A freezing point osmometer provides the most accurate and reliable results available. Ours is fully automatic over the 3,000 mOsm/kg range and has multiple operating ranges for even higher accuracy.

Additional Tests

R.D. Laboratories maintains a large array of analytical instrumentation capable of performing a wide variety of procedures too numerous to comprehensively list here.  Below are a few additional tests we perform.  If you do not see the procedure that meets your needs please contact us for more information.

  • Elemental Analysis
  • Disintegration
  • Tablet Hardness
  • Closed-cup flash point
  • Tablet Friabilator
  • Refractive Index
  • Nephelometer
  • Fluorometric Spectrophotometry
  • Mercury Analysis
  • Residual Solvents
  • Microwave Digestion
  • Optical/Specific Rotation
  • UV-Vis
  • FTIR
  • Brookfield viscosity
  • Impurities testing