Galbraith Laboratories Inc.

Thin-Layer Chromatography (TLC) identification relies on the comparison of a TLC analysis of an unknown sample to that of a reference substance. The distance traveled by the unknown sample is compared to that of the reference substance.

Carbon, Hydrogen and Nitrogen Analysis

Analysis for carbon, hydrogen and nitrogen is conducted in an elemental analyzer that burns a small portion of sample in an oxygen atmosphere to create the combustion byproducts CO2, H2O and N2 (or NOx). The gases are then separated and quantified by either an infrared cell or a thermal conductivity detector. Results are reported in wt % of the corresponding element.

Sample Preparation

Samples are prepared by weighing a sample portion into a capsule (typically made of tin foil), carefully crimping the capsule and then loading it into an auto sampler. Typical masses taken for this test are between 1 and 5 mg, though more may be taken for some instruments. The autosampler drops the sample capsule into a furnace where the combustion occurs. In the case of samples that exhibit poor recovery of carbon, hydrogen or oxygen, a combustion aid, such as Vanadium Pentoxide, may be added to the sample before the capsule is crimped. Presence of this combustion aid improves the overall combustion of the sample and may improve recovery.

Methods

Galbraith Laboratories employs four different analytical methods for the determination of CHN. The methods are largely aligned with different models of Elemental Analyzers. Each of Galbraith’s methods are based on industry methods, but have extra QC requirements embedded to ensure the accuracy of results.

Analysis of Carbon, Hydrogen and Nitrogen

Samples are introduced into a furnace and are quantitatively combusted in an oxygen atmosphere. The instrument detects and quantifies the gaseous combustion byproducts: CO2, H2O and N2 (or NOx). Most instruments quantify each of the elements in every analysis, even if only one is desired.

Quantitation Limit

Quantitation limit varies among the instruments. The range is 0.5%-1%. Results that are below the quantitation limit are reported as a less than value, i.e. <0.5%.

Results

Results are reported in % (wt/wt) unless another unit is requested.

USP <467> contains limits for residual solvents in pharmaceutical substances along with procedures for measuring residual solvent concentrations. Residual solvent limits are based on their toxicity and hazards. Solvents are ranked into one of three classes: compounds in Class 1 are considered the most toxic/hazardous. Compounds in Class 3 are considered the least toxic/hazardous. The general chapter also contains three procedures for measuring residual solvent concentrations. A list of the solvents in the scope of USP <467> is presented in the Appendix of the general chapter.

Method

The methodology is given in USP <467>. Three (3) procedures each are given for water soluble and water insoluble articles. One of the three procedures must be used according to decision criteria given in the general chapter. USP <467> relies on Gas Chromatography - Flame Ionization Detection (GC-FID) for analysis. Click here to see more information on GC-FID.

Procedures

Each of the procedures in USP <467> can be characterized as follows:

• Procedure 1: Analysis of the test solution and comparison to an external standard
  
• Procedure 2: Analysis of the test solution on a secondary column and comparison to an external standard
  
• Procedure 3: Quantification of the analyte solvent
  

Analysis

LC instruments are externally calibrated with the use of approximately 5 calibration standards. Sample solutions are injected onto the column and are separated based on their relative affinity for the stationary (column) and mobile phases. Components of the analysis solution are detected using one of the available detectors to provide a sample chromatogram. The area under the desired (target) peak(s) is integrated and is compared to the calibration curve to provide the concentration.

Quantitation Limit

Unless otherwise evaluated, the quantitation limit (QL) depends on the concentration of the lowest calibration standard used to calibrate the instrument. Results that read below the QL are reported as less than values, i.e <50 ppm.

Results

Results are reported using the mass of sample originally taken for the analysis. Typical reporting units are ppm, mg/L, or %. Other units may be reported. For any questions on LC analysis, please Contact a member of our Technical Team for more information.

Regulated Submissions

The general methodology is suitable for the analysis of regulated samples. The method is considered validated to a reference substance, but not to the sample matrix unless a formal validation is conducted.

Inductively Coupled Plasma – Mass Spectrometry (ICP-MS), measures elements on the basis of their mass to charge ratio. Galbraith Laboratories commonly employs ICP-MS to measure metallic elements, metalloids and some non-metal elements (such as bromine and iodine) in a variety of sample matrices.

Preparation

Each successful analysis begins by adequately digesting the sample for analysis. The final outcome of each preparation is to afford a homogenous solution of the analyte in the analysis solvent. In most cases, the analysis solvent is water that is stabilized with acid.

Analysis

Sample solutions are introduced into the instrument by way of a peristaltic pump. The solution is nebulized into an aerosol that is transported to a plasma torch. Metal ions in the sample solution are subjected to intense heat in a radio-frequency inductively coupled argon plasma. The ions are transported from the plasma through a vacuum interface into a quadrupole where they are separated on the basis of their mass to charge ratio (m/z). Metal ion concentrations of unknown samples are determined by comparison to an external calibration of the instrument.

Method

Galbraith's general method was written from nationally accepted methods, such as EPA SW846 6020. It also meets the general guidance of USP <730>.

Quantitation Limit

Unless otherwise evaluated, the quantitation limit (QL) depends on the concentration of the lowest calibration standard used to calibrate the instrument. Results that read below the QL are reported as less than values, i.e <50 ppb.

Results

Results are reported using the mass of sample originally taken for the analysis. Typical reporting units are ppm, ppb, mg/L, or µg/L. Other units may be reported.

Regulated Submissions

The general methodology is suitable for the analysis of regulated samples. The method is considered validated to a reference substance, but not to the sample matrix unless a formal validation is conducted.

Karl Fischer Water Testing

Karl Fischer (KF) water analysis quantifies free water and waters of hydration. Samples are weighed on an analytical balance and are then either transferred directly to the titration cell, or are added to a sample oven. In the case of the sample oven, moisture from the sample is evolved from the sample by heat and is transported to the titration cell by way of an inert gas.

Performed By:

• Volumetric Testing
  
• Coulometric Testing
  

Ion Chromatography (IC) measures ionic analytes based on their relative affinity for mobile and stationary phases. This technique is commonly employed to measure anions and cations in a variety of sample matrices.

Inductively Coupled Plasma – Atomic Emission Spectroscopy (ICP-AES) also known as Inductively Coupled Plasma – Optical Emission Spectroscopy (ICP-OES), measures element-specific spectra emitted from atoms and atomic species in a heated in plasma. Galbraith Laboratories commonly employs ICP-AES to measure Group I metals, Group II metals, Transition metals, Metalloids (such as boron, silicon, germanium, etc.) and some Non-Metal elements (such as sulfur and iodine) in a wide variety of sample matrices.

Preparation

Each successful analysis begins by adequately digesting the sample for the analysis. The final outcome of each preparation is to afford a homogenous solution of the analyte in the analysis solvent. In most cases, the analysis solvent is water that is stabilized with acid.

Analysis

Sample solutions are infused into the ICP instrument by way of a peristaltic pump. The solution is nebulized into an aerosol that is transported to a plasma torch. Metal ions in the sample solution are subjected to intense heat in a radio-frequency inductively coupled argon plasma. The elements emit characteristic spectra which are separated by a grating. The intensity of the emission lines are monitored by a photosensitive device. Metal ion concentrations of unknown samples are determined by comparison to an external calibration of the instrument.

Method

Galbraith's general method was written from nationally accepted methods, such as EPA SW846 6010B. It also meets the general guidance of USP <730>.

Quantitation Limit

Unless otherwise evaluated, the quantitation limit (QL) depends on the concentration of the lowest calibration standard used to calibrate the instrument. Results that read below the QL are reported as less than values, i.e <0.5 ppm.

Results

Results are calculated using the mass of sample originally taken for the analysis. For example if 250 mg of sample is dissolved in 25 mL of water and the solution reads 0.1 mg/L, then the final result is 0.1 x 25 / 0.25 or 10 ppm. Typical reporting units are ppm, mg/L or %. Other units may be reported. Regulated Submissions The general methodology is suitable for the analysis of regulated samples. The method is considered validated to a reference substance, but not to the sample matrix unless a formal validation is conducted.

Optical rotation measures the rotation of polarized light at a specific wavelength as it travels through a solution at a specified temperature and concentration.

Thermogravimetric Analysis (TGA) measures the amount and rate change in the mass of a sample as a function of temperature or time under a controlled environment.

Flame Atomic Absorbance (FAA) relies on aspirating a sample and atomizing it in a flame. A light beam from a lamp is directed through the flame and into a monochoromator which focuses the detector on the wavelength of maximum absorption of the element. The amount of light absorbed by the flame is inversely proportional to the amount of that element in the sample. Metal ion concentrations of unknown samples are determined by comparison to an external or internal calibration (method of standard addition) of the instrument. The concentration of the metal(s) in the sample is typically expressed in terms of the original mass taken for the analysis (wt/wt).

Graphite Furnace Atomic Absorbance (GFAA)

Graphite Furnace Atomic Absorbance (GFAA) is similar to FAA in that it relies on atomic absorption to measure metal concentrations, but it differs in that it uses a furnace to atomize the sample, not a flame. This technique offers the advantage of greater atomization of the sample, which affords either a lower detection limit (than conventional FAA) or the use of less sample. Metal ion concentrations of unknown samples are determined by comparison to an external or internal calibration (method of standard addition) of the instrument. The concentration of the metal(s) in the sample is typically expressed in terms of the original mass taken for the analysis (wt/wt).

Liquid Chromatography (LC) measures non-volatile and semi-volatile organic analytes based on their relative affinity for a mobile and stationary phases. This technique is commonly employed to measure relatively polar and/or heat sensitive analytes in a variety of sample matrices.

Methods

Galbraith's LC method is written to handle a wide range of sample types. The method specifies a range of columns and allows for unspecified columns. The method also allows for a range of mobile phase components. Click below to view a copy of the method summary: LC-100-HPLC-Analysis-GLI-Method-Summary

Detectors

The following detectors are available for LC analysis:

1. A Refractive Index Detector (RI) measures the change in the refractive index of the mobile phase during elution of an analyte.
   
2. An Ultraviolet-Visible (UV-VIS) detector measures the change in the absorbance of ultraviolet or visible light by the mobile phase during elution of an analyte.
   
3. A Diode-Array Detector (DAD) uses the same principle as the UV-VIS detector, yet it offers the ability to monitor multiple wavelengths during analysis.
   

Separate methods for each detector are not provided. The detector will be chosen based on the identiy(ies) of the analyte(s).

Preparation

Each successful analysis begins by adequately dissolving the sample for analysis. Many solvents may be used as long as they don't interfere in the analysis and sufficiently dissolve the sample.

Analysis

LC instruments are externally calibrated with the use of approximately 5 calibration standards. Sample solutions are injected onto the column and are separated based on their relative affinity for the stationary (column) and mobile phases. Components of the analysis solution are detected using one of the available detectors to provide a sample chromatogram. The area under the desired (target) peak(s) is integrated and is compared to the calibration curve to provide the concentration.

Quantitation Limit

Unless otherwise evaluated, the quantitation limit (QL) depends on the concentration of the lowest calibration standard used to calibrate the instrument. Results that read below the QL are reported as less than values, i.e <50 ppm.

Results

Results are reported using the mass of sample originally taken for the analysis. Typical reporting units are ppm, mg/L, or %. Other units may be reported.

Regulated Submissions

The general methodology is suitable for the analysis of regulated samples. The method is considered validated to a reference substance, but not to the sample matrix unless a formal validation is conducted.

Assays and Monographs

In the past half century, Galbraith Laboratories, Inc. has performed numerous assays, monographs and tests.
Familiarity with these methods makes Galbraith Laboratories, Inc. a valuable partner in applying existing
procedures to experimental pharmaceuticals or new products.

Reagent Chemicals (ACS)
European Pharmacopoeia (EP)
Food Chemicals Codex (FCC)
Japanese Pharmacopoeia (JP)
U.S. Pharmacopeia/National Formulary (USP/NF)

IR spectroscopy measures the amount of infrared light absorbed over a range of wavelengths. The typical range is 2.5 µm to 15 µm, or 4,000 to 670 cm-¹. Infrared (IR) Spectroscopy is a valuable tool in characterizing functional groups present in organic and inorganic compounds. Galbraith performs IR spectroscopy measurements using a Fourier-Transform Infrared (FT-IR) instrument.

Most IR testing falls into one of three categories:

1. Comparison to a USP reference standard for the purpose of identity verification
   
2. Comparison to a library of IR spectra for the purpose of identifying of an unknown compound
   
3. Scan of a compound to acquire the IR spectrum, especially for the purpose of showing that a particular peak (functional group) is present in the scan
   

Methods

The following methods, given in USP <197>, are available at Galbraith Laboratories:

• USP <197>A: Analysis using an Attenuated Total Reflectance (ATR) cell
  
• USP <197>K: Analysis is conducted on a mixture of the compound pressed into a pellet of potassium bromide
  
• USP <197>M: Analysis is conducted on a mixture of the compound dissolved in mineral oil
  
• USP <197>F: Analysis is conducted on the compound that is suspended between sodium chloride or potassium bromide plates
  

Preparation

Samples are prepared according to the section of USP <197> chosen (see above). For USP materials, the reference substance and sample will be dried prior to analysis if required.

Analysis

IR scans are acquired over the range of about 2.5 to 15 µm. If a comparison to a reference substance is required, an overlay of the unknown and the reference substance is made by the technician.

Reporting

The reported information will be based on the nature of the order:

1. If a pass/fail identification of the compound is required, the final report will only indicate the pass/fail outcome.
   
2. If a comparison to library spectra is made, a copy of the unknown scan is provided along with a series of the best library matches.
   
3. If a spectrum on a compound is ordered, a copy of the scan will be provided with the report. The scan will contain labels of the major peaks.
   

Regulated Submissions

The general methodology is suitable for the analysis of regulated samples. The method is considered validated to a reference substance, but not to the sample matrix unless a formal validation is conducted.

Gas Chromatography (GC) measures volatile analytes based on their boiling point and affinity for a stationary phase. This technique is commonly employed to measure solvents and other volatile analytes in a variety of sample matrices.

Methods

Galbraith's GC methodology is divided according to the injection technique. Galbraith offers direct and headspace injection techniques. Both of these injection techniques may be coupled with the detectors below.

Injection Techniques

Direct injection is usually reserved for analytes that exhibit high boiling points, to ensure that the analyte is injected into the column. Direct injection is also used in area percent (%) assays to ensure that unknown contaminates are injected onto the column.

Headspace injection is used for analytes that have relatively low boiling points. This technique is desirable since the sample matrix is not injected onto the column. Often, headspace injection affords lower detection limits than direct injection.

Detectors

Flame Ionization Detectors (FID) detect the by-products created during the combustion of organic compounds in a hydrogen flame. Thermal Conductivity Detectors (TCD) measure the change in heat flow from a GC column relative to a reference flow of carrier gas. Mass Spectrometer (MS) detectors separate analytes based on their mass to charge ratio (m/z). Separate methods for each detector are not provided. The method is chosen based on the injection technique and then the detector specified. All detectors are available for each injection technique.

Preparation

Each successful analysis begins by adequately dissolving the sample for analysis. Many solvents may be used as long as they don't interfere in the analysis and sufficiently dissolve the sample.

Analysis

GC instruments are externally calibrated with the use of approximately 5 calibration standards. Sample solutions are injected onto the column and are separated based on their boiling point and affinity for the stationary (column) phase. Components of the analysis solution are detected using one of the available detectors to provide a sample chromatogram. The area under the desired (target) peak(s) is integrated and is compared to the calibration curve to provide the concentration.

Quantitation Limit

Unless otherwise evaluated, the quantitation limit (QL) depends on the concentration of the lowest calibration standard used to calibrate the instrument. Results that read below the QL are reported as less than values, i.e <50 ppm.

Results

Results are reported using the mass of sample originally taken for the analysis. Typical reporting units are ppm, mg/L, or %. Other units may be reported.

Regulated Submissions

The general methodology is suitable for the analysis of regulated samples. The method is considered validated to a reference substance, but not to the sample matrix unless a formal validation is conducted.

A wide range of tests for the analysis of halogens or halides. Testing can be performed as a targeted analysis for fluoride and iodide using ion selective electrode detection and for chloride and bromide by ion chromatography. There are also several combined techniques to determine a total halogens or total halides result.

Halogen Testing Options

• Fluoride Ion by Ion-Selective Electrode
  
• Fluorine by Oxygen Flask Combustion
  
• Fluorine by Pyrohydrolysis
  
• Chlorine by Bomb/Ion Chromatography
  
• Bromine by Bomb/Ion Chromatography
  
• Volumetric Determination of Bromine and Iodine
  
• Iodine by Ion-Selective Electrode
  
• Total Halogens/Halides
  
• Total Halogens/Halides, Trace Level

Combustion Analysis for CHNOS

Our CHNOS department now performs a range of instrumental methods to measure gas products evolved from combusted compounds. In addition, Galbraith Laboratories, Inc. offers the ability to grind your
samples when received. With over half a century of experience in handling these analyses, our expertise is well defined in this field. To provide clients with the most accurate data possible, we offer multiple method options along with our comprehensive Quality Assurance program.

Elemental Analysis

• Carbon Analysis
  
• Hydrogen Analysis
  
• Nitrogen Analysis
  
• Oxygen Analysis
  
• Sulfur Analysis
  

Sample Combustion

Parr Bomb Combustion

Parr Bomb Combustion is a preparative technique used to prepare samples for instrumental analysis. This technique is commonly used to prepare samples for halogen and halide analysis by Ion Chromatography (IC).

Methods

Galbraith's internal procedure for parr bomb combustion is G-55.

Preparation

A portion of sample is weighed into a combustion cup. A combustion aid, such as benzoic acid or mineral oil may be added to improve combustion. A known volume of absorber solution is placed in the bottom of the bomb. The Parr Bomb is assembled and is charged to 30 ATM with pure oxygen.

Ignition

When ignited, the sample is burned quantitatively and any covalent halogen is converted into the corresponding halide salt. The halide and any native halide present in the sample are absorbed into the absorber solution. The absorber solution is poured into a separate container and is then analyzed by IC.

Differential Thermal Analysis (DTA) measures the temperature difference between an unknown sample and a reference material as a function of temperature while the unknown sample and reference material are subjected to a controlled temperature program. The analysis shows reactions and phase changes of
the unknown sample as it is subjected to the temperature program.