Dietary Supplements Solutions


Rtx-1301 (G43) Columns (fused silica)

low- to midpolarity phase

  • General-purpose columns for residual solvents, alcohols, oxygenates, and volatile organic compounds.
  • Equivalent to USP G43 phase.

Stabilwax Columns (fused silica)

polar phase; Crossbond polyethylene glycol

  • Rugged enough to withstand repeated water injections.
  • Low-bleed PEG column ensures long column lifetimes.
  • Temperature range: 40 °C to 260 °C.
  • Equivalent to USP G14, G15, G16, G20, and G39 phases.

USP Residual Solvent Standards

  • USP equivalent standards for the revised USP <467> general chapter—compliance without the cost—compare prices today.
  • The only complete source for USP <467>.

Everything you need for QuEChERS!

  • Fast, simple sample extraction and cleanup using dSPE—Fourfold increases in sample throughput.
  • Complete offering for AOAC and European Methods.
  • Single and multiple component standards as specified in EN Method 15662.

Rxi-5Sil MS Columns (fused silica)

low-polarity phase; Crossbond 1,4-bis(dimethylsiloxy)phenylene dimethyl polysiloxane

  • Engineered to be a low-bleed GC-MS column.
  • Excellent inertness for active compounds.
  • General-purpose columnsideal for GC-MS analysis of semivolatiles, polycyclic aromatic compounds, chlorinated hydrocarbons, phthalates, phenols, amines, organochlorine pesticides, organophosphorus pesticides, drugs, solvent impurities, and hydrocarbons.
  • Temperature range: -60 °C to 350 °C.

Ultra Aqueous C18 Columns (USP L1)

Particle Size: 3 µm or 5 µm, spherical
Pore Size: 100 Å
Carbon Load: 15%
End-Cap: no
pH Range: 2.5 to 8
Temperature Limit: 80 °C
USP Phase Code: L1
Phase Category: modified C18
Ligand Type: proprietary polar modified and functionally bonded C18

Audio Slideshow

Introduction to QuEChERS

A brief overview of the QuEChERS process, and how it can simplify your sample preparation workflow.



Revised USP 467 Residual Solvent Method - Satisfy New Method Requirements with Restek Columns and Standards

The United States Pharmacopeia recently revised the general chapter on residual solvent analysis, USP <467>, to mirror the International Conference on Harmonization (ICH) guidelines for the identification, control and quantification of residual solvents. This revision, effective July 1, 2007, replaces previous methods that were not consistent with the ICH guidelines. Here we provide an overview, chromatograms, and technical tips for successfully running the new procedure.

General Interest

Pesticides in Dietary Supplements: - Advantages of QuEChERS vs. PAM 303

Restek has developed the first QuEChERS-based method for determining pesticide residues in dietary supplements. This simple, cost-effective procedure reduces matrix interferences as well as sample prep variation among technicians.

Foods, Flavors & Fragrances

Comprehensive Pesticide Residue Analysis by LC-MS/MS Using an Ultra Aqueous C18 Column

Analysis of pesticide residues in foods is complicated by the large number of target compounds. LC-MS/MS analysis using an Aqueous C18 column provides more comprehensive results than GC alone.

Foods, Flavors & Fragrances

Rapid Characterization of Garlic Volatiles—No Sample Prep Required! - Using Headspace GC/MS and an Rxi®-5ms Capillary Column

Chromatographic methods for garlic and garlic powder are used by the food and dietary supplement industries to monitor product quality. Here we present a headspace gas chromatography mass spectrometry (HS GC/MS) method for garlic flavor and odor components using an Rxi®-5ms column. This method eliminates sample preparation making the bench work simple and fast. The experimental set-up is ideal for both screening analysis and low-level trace analysis.

Foods, Flavors & Fragrances

Monitor Anitoxidants in Tea Extract - Using an Ultra Aqueous C18 HPLC Column and Unique® TOFMS

An Ultra Aqueous C18 column enables you to use the conditions most effective for this analysis: gradient elution in high aqueous mobile phases. The C18 chains will not collapse in the presence of a high water content. Use this chromatographic system to extract data for specific compounds of interest and to manually inspect spectra for phenolic glycosides, esters of phenolic acid, or other compounds.

PDF Document

Determining Pesticides in Dietary Supplements with QuEChERS Extraction, Cartridge SPE, and GCxGC-TOFMS

The novel approach used here combines QuEChERS extraction, cartridge SPE cleanup, and GCxGC-TOFMS analysis, resulting in good recoveries for a wide range of pesticides in dietary supplements. Matrices include dandelion root, sage, and a multi-herb finished product.

PDF Document

QuEChERS Methodology: AOAC Approach Instruction Sheet

Instruction Sheet for QuEChERS Methodology: AOAC Approach.

PDF Document

QuEChERS Methodology: European and Mini-Multiresidue Method Instruction Sheet

Instruction Sheet for QuEChERS Methodology: European and Mini-Multiresidue Method.

PDF Document

Q-sep dSPE Sample Clean-up Instruction Sheet

Instruction Sheet for Q-sep dSPE Sample Clean-up.

PDF Document

Developing New Methods for Pesticides in Dietary Supplements

QuEChERS is a simple, effective approach to sample prep that can be applied to the analysis of pesticides in dietary supplements. Here, we demonstrate a QuEChERS, cSPE, GC-TOFMS procedure that results in good recoveries for a wide range of pesticides in dandelion root.

PDF Document

Residual Solvent Analysis: Implementing USP <467>

This 12-page reference includes a of headspace fundamentals, the revised USP <467> method (July, 2008), chromatography for Procedures A, B, and C, and technical tips for optimization. Guidance on fast, effect method development is given.

PDF Document

Fast, Simple QuEChERS Extraction and Cleanup of Pesticide Residue Samples

QuEChERS dSPE methods simplify extract cleanup, reduce material costs, and improve sample throughput. Here we demonstrate the effectiveness of QuEChERS sample cleanup using a multiresidue analysis of pesticides on strawberries.