Not all column deactivations are appropriate for analyzing basic compounds. Here we demonstrate the
effect of column inertness on peak shape, and discuss its role in improvingmethod accuracy,
sensitivity, and development time. (PDF - 227kB)
Screeningmethods for consumer product adulteration cases, such as the recent Tylenol recall, can
benefit from fast QuEChERS-based sample preparation and sensitive, full mass-range GC/TOF-MS.
Fast Screening of Recalled Tylenol® for Tribromoanisole and
Related Adulterants Using QuEChERS and GC-TOFMS
The novel approach used here combines QuEChERS extraction, cartridge SPE cleanup, and
GCxGC-TOFMS analysis, resulting in good recoveries for awide range of pesticides in dietary
supplements. Matrices include dandelion root, sage, and amulti-herb finished product.
Determining Pesticides in Dietary Supplements with QuEChERS
Extraction, Cartridge SPE, and GCxGC-TOFMS
Restek USLC™ columns offer thewidest range of selectivity available and are an integral part of
successful method development. Ideal for column switching systems, these columns provide
orthogonal separations to create optimal resolution and robust methods—all in a 4-column set. (PDF -
1813kB)
USLC™ Columns: Choose Columns Fast. Develop Methods Faster.
Column choice is a critical factor in successfully transferringmethods between UHPLC and HPLC. Here,
we discuss the column qualities that contribute to the successful integration of UHPLC technology.
Column Choice: A Critical Factor for Successful UHPLC Integration
Novel column chemistries are a simple change in an already budgeted consumable that can lead to
optimized andmore reliablemethods—giving a fast return on aminimal investment.
Novel Column Chemistry—High Impact, Low Cost Technology
The Pinnacle DB Biphenyl column offers enhanced retention and alternate selectivity for aromatic,
unsaturated, and sulfur-containing hydrophilic compounds. Herewe demonstrate significantly greater
retention of sulfone- and sulfoxide-containing drug probes, compared to phenyl, phenyl hexyl, and
alkyl (C18) columns. Only the Biphenyl column, using pi-pi interactions, separated both test probes to
k′ > 2, the level needed to ensure separation from unretainedmatrix contaminants.
Beyond C18—Increase Retention of Hydrophilic Compounds Using
Biphenyl Columns
Two options for the analysis of PGIs in API have been developed byMerck and Restek tomeet different
laboratory needs. The first option is a fast method for the analysis of sulfonate esters on the Rxi -5Sil
MS column. The second option is a comprehensivemethod for the analysis of both sulfonate esters and
alkyl halides on the Rtx -200 column. Bothmethods require very little sample preparation, which helps
increase laboratory productivity.
Two Options for Analyzing Potential Genotoxic Impurities in Active
Pharmaceutical Ingredients
Analyzing basic compounds can be somewhat troublesome on traditional alkyl stationary phases,
namely conventional C18 columns. This is largely due to the interaction of analytemolecules with
silanol groups present on the silica surface. To better understand the workings of silanol interactions, it
is important to consider the composition of the support material. Silica is themost commonly used
support in the production of HPLC columns, mainly because it is well-suited to high-pressure
chromatographic separations, giving high efficiencies and good reproducibility. Silica offers bed and
pressure stability and is highly porous, which ultimately gives rise to its large surface area, increased
bonding capacity and high peak efficiencies. Silica also possesses widely-studied and effective bonding
chemistries, making possible diverse analyte selectivities through awide variety of bonded stationary
phases.
How do intrinsically base-deactivated phases work?
Ultra High Pressure Liquid Chromatography (UHPLC) is a rapidly growing technique that can provide
faster analysis times. Scaling conventional HPLCmethods down toUHPLC can be an effectiveway to
take advantage of shorter run times and increase sample throughput. Herewe review the factors that
must be considered when scaling down an existingmethod. A sulfonamidesmethod transfer is used as
an example; chromatograms and formulas for all required calculations are included.
Easy Transfer of HPLCMethods to UHPLC
Ultra-high pressure liquid chromatography (UHPLC) can significantly increase efficiency and produce
faster separations. The small particle sizes used in UHPLC improve efficiency; however selectivity is still
themost important factor affecting compound resolution. Herewe demonstrate the importance of
stationary phase choice in UHPLC separations. By optimizing selectivity for your analytes of interest,
faster separations can be achieved without compromising resolution.
Optimize Selectivity & Efficiency in UHPLC Separations
The United States Pharmacopeia recently revised the general chapter on residual solvent analysis, USP
<467>, tomirror the International Conference on Harmonization (ICH) guidelines for the identification,
control and quantification of residual solvents. This revision, effective July 1, 2007, replaces previous
Revised USP 467 Residual Solvent Method
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