Columns Acclaim ® Surfactant Column A Simple Solution to Difficult Challenges Acclaim Surfactant columns are high-efficiency specialty silica columns for separating anionic, nonionic, and cationic surfactants: • Ideal selectivity for separation of anionic, nonionic, and cationic surfactants • Excellent peak shapes for cationic surfactants • Improved resolution for ethoxylated surfactants • Compatible with highly aqueous mobile phases • Methods compatible with various detectors • Broad range of applications Ideal Selectivity for the Separation of Anionic, Nonionic, and Cationic Surfactants The Acclaim Surfactant column is a new column designed for, and ideally suited to, the separation of a variety of different surfactants. This column incorporates a proprietary silica-based bonded phase that offers ideal selectivity and unprecedented capacity for separating cationic, nonionic and anionic surfactants in a single run. The simple, volatile mobile phases are compatible, with mass spectrometry detection which facilitates the application of this column to trace-level analyses of surfactants in various matrices, includ- ing pharmaceutical formulations and environmental samples. Surfactants are widely used in industrial, agricultural, and pharmaceu- tical markets, in products as diverse as pesticides, detergent powders, petro- leum products, cosmetics, and pharma- ceuticals. Their separation and identifi- cation can be a challenge due both to the diversity of surfactants and com- plexity of the sample matrix. Peaks: 1. Xylene sulfonate 2. Lauryldimethylbenzyl ammonium chloride 3. Octylphenoxyethoxyethyl dimethylbenzyl ammonium chloride 4. Triton X-100 5. Decyl sulfate 6. Dodecyl sulfate 7. C 10 -LAS 8. C 11 -LAS 9. C 12 -LAS 10. C 13 -LAS mV Minutes 0 5 10 15 20 25 30 35 40 1 2 3 4 5 6 7 10 9 8
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Acclaim Surfactant Column Data Sheet - Cromlab€¦ · pesticides, detergent powders, petro-leum products, cosmetics, and pharma-ceuticals. ... chromatographic analysis using the
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Colum
ns A c c l a i m ® S u r f a c t a n t C o l u m nA S i m p l e S o l u t i o n t o D i f f i c u l t C h a l l e n g e s
Ideal Selectivity for the Separation ofAnionic, Nonionic, and CationicSurfactants
The Acclaim Surfactant columnis a new column designed for, andideally suited to, the separation of avariety of different surfactants. Thiscolumn incorporates a proprietarysilica-based bonded phase that offersideal selectivity and unprecedentedcapacity for separating cationic,nonionic and anionic surfactants in asingle run. The simple, volatile mobilephases are compatible, with massspectrometry detection which
facilitates the application of thiscolumn to trace-level analyses ofsurfactants in various matrices, includ-ing pharmaceutical formulations andenvironmental samples.
Surfactants are widely used inindustrial, agricultural, and pharmaceu-tical markets, in products as diverse aspesticides, detergent powders, petro-leum products, cosmetics, and pharma-ceuticals. Their separation and identifi-cation can be a challenge due both tothe diversity of surfactants and com-plexity of the sample matrix.
The separation of surfactants istypically accomplished using HPLC.Reversed-phase and ion-exchangechromatography are the most popularapproaches, but normal-phase and size-exclusion chromatography are alsoused, depending on the application.Although many HPLC stationaryphases are available and have been usedfor the analysis of surfactant formula-tions, none of these columns have beendesigned specifically for this applica-tion, nor are they capable of separatinganionic, nonionic, and cationic surfac-tants in a single chromatographic run.Figure 1 shows the difference betweena conventional C18 column and theAcclaim Surfactant column for theseparation of a mixture of anionic andnonionic surfactants. The AcclaimSurfactant column provides excellentseparation, whereas the C18 columnfails to resolve all the surfactants underthe same conditions.
Excellent Peak Shapes for CationicSurfactants
Reversed-phase chromatography,using a C18 column, is often used forthe separation of anionic surfactants.When analyzing cationic surfactants,however, it is often difficult to obtainsharp, symmetrical peaks due primarilyto the presence of free silanols. Thenovel bonding chemistry of theAcclaim Surfactant phase allows foreffective deactivation of free silanolstoward positively charged cationicsurfactants, resulting in excellent peakshapes, as shown in Figure 2. Bycomparison, a C18 column tested undersimilar conditions demonstrates anextended retention time and peak tailing.
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Figure 3. Improved resolution between oligomers in ethoxylated surfactants.
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Figure 4. Analysis of a strongly hydrophilic hydrotrope.
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Dimensions: 4.6 × 150 mmMobile Phase: Acetonitrile/0.1 M NH4OAc, pH5.4
v/v 40/60 for Acclaim Surfactantv/v 50/50 for Symmetry C18 (Waters) column
As a consequence of its novelcolumn chemistry, the Acclaim Surfac-tant column exhibits a unique polaritythat provides significantly improvedresolution for individual oligomers ofethoxylated surfactants compared withconventional C18. Figure 3 provides acomparison between the AcclaimSurfactant column and a conventionalC18 for the characterization of TritonX-100. The Acclaim surfactant columnexhibits significantly improved resolutionbetween the oligomers.
Compatible with Highly AqueousMobile Phase Conditions
High-density C18 columns areoften unsuitable for analyzing stronglyhydrophilic hydrotropes, such assodium naphthalene sulfonate andxylene sulfonate. The problem arisesbecause these analyses require a highlyaqueous mobile phase that often leadsto undesirable “dewetting”. Asillustrated in Figure 4, the novelchemistry of Acclaim Surfactantcolumn provides excellent resolutionbetween isomers of xylene sulfonate,while under the same condition littleor no retention is observed on theconventional C18 column.
Methods Compatible with VariousDetectors (ELSD, UV, MS ConductivityDetection)
UV absorbance is the mostpopular detection method in HPLC, dueto its ease of use and sensitivity(Figures 3–5 and 18–20). The drawbackwith this approach is that the analytemust have a chromophore to bedetected and many surfactants do not.
Although refractive index (RI)detection is a universal detectionmethod, capable of detecting allanalytes, it is incompatible withgradient methods, exhibits low sensitiv-ity, and thus is only used when otherdetection methods are not applicable.
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Evaporative light-scatteringdetection (ELSD) is not only a univer-sal detection method, but also iscompatible with gradient methods andis far more sensitive than RI. In addition,methods developed with ELSD can beeasily transferred to LC-ESI-MSapplications with little or no modifica-tions, because both detectors share thesame mobile phase requirements(Figures 1, 2, 8, 11–14 and 16–22).
Mass spectrometry (MS) is aninherently sensitive and universalmethod and has become the widelyaccepted tool for characterization oforganic compounds. The soft ionizationtechniques, such as electrosprayionization (ESI), have greatly increased
the applicability of MS detection tosurfactant analysis. As shown inFigures 6, 10, and 15, the AcclaimSurfactant column can be used for theanalysis of anionic, cationic, andnonionic surfactants using LC-ESI-MSand ammonium acetate eluents.
Suppressed conductivity detec-tion can also be used for surfactantanalysis and provides certain advan-tages for analyzing trace levels ionicsurfactants in complex matrices.Figures 7 and 9 show the separation ofvarious anionic and cationic surfactantson the Acclaim Surfactant column,using a borate buffer and acetic acidmobile phases, respectively.
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Figure 5. Analysis of sodium dodecylbenzene sulfonate (LAS).
mass spectrometer)Inj. Volume: 25 µLDetection: MS (ESI negative, probe 300 °C,
cone 20 V needle 2.5 KV,SIM 265.2, span 0.3 m/z)
Peak: Sodium lauryl sulfate (1 ppm)
Broad Range of Applications
Anionic SurfactantsAnionic surfactants account for
60% of surfactant use in the UnitedStates, where they are popular ingredi-ents in detergent powders. This popular-ity arises because of their effectivenesscompared with other surfactants inparticulate soil removal, especially fromnatural fabrics, and because they areeasily spray-dried.
Linear alkylbenzenesulfonates(LASs) are the most widely usedsurfactants, due to their low cost andrapid degradation under aerobic condi-tions. The synthesis of LAS typicallyleads to a mixture of positional isomersthat results in a very complex samplematrix that can be a challenge to separateeffectively by chromatography. Tosimplify quantitative analysis, isocraticconditions are often used to produce onlysingle peaks for the same size homo-logues species. As shown in Figure 5,LAS can be separated on the AcclaimSurfactant column into simple, singlepeaks corresponding to a homologousseries, whereas the Acclaim PA columngives more complex chromatograms.
Alkyl sulfates are the sulfuric acidesters of linear alcohols. They arefrequently employed as additives incosmetics and detergents. Figure 6shows the analysis of lauryl sulfate,a major ingredient in shampoo, on anAcclaim Surfactant column usingLC-ESI-MS and an ammoniumacetate eluent.
Alkylether sulfates are preparedby adding oxyethylene groups to analcohol that is then sulfated. Oxyethy-lation enhances water solubility andfoaming, making these surfactantsideal components in shampoos anddetergents. Figure 7 shows the analysisof laureth sulfate using suppressedconductivity detection.
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Figure 7. Analysis of ammonium laureth sulfate using conductivity detection.
(B) 0.1 M NH4OAc, pH 5.4Gradient: 25–85% A in 30 minTemperature: 30 °CFlow Rate: 1 mL/minInj. Volume: 10 µLDetection: ELSD
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2-Hydroxyethylbenzyl coco imidazolinium chloride
Diethyl heptadecyl imidazolinium ethylsulfate
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Nonionic SurfactantsNonionic surfactants account for
about 40% of the worldwide consump-tion of surfactants. Most nonionicsurfactants are considered low-foamingproducts, have good cold watersolubility, and low critical micelleconcentration. Their compatibility withcationic fabric softeners makes thempreferable in certain formulations.Figures 13–16 show chromatographicanalyses of three individual nonionicsurfactants using the Acclaim Surfac-tant column.
Figure 13. Analysis of PEG monoethyl ether (MW-550).
Polyethylene Glycols (PEGs)Polyethylene glycols (PEGs) are
often nonsurfactant impurities found inethoxylated surfactants, typically in therange of 1–10%. The oligomer distribu-tion is similar to, but broader than thatof the surfactant. Figure 17 illustratesthe exceptional resolution of theAcclaim Surfactant column for indi-vidual oligomers in various PEGs.
Figure 16. Analysis of ZONYL FSO fluorosurfactant.
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Column: Acclaim Surfactant, 5 µmDimensions: 4.6 × 150 mmMobile Phase: (A) Acetonitrile, (B) H2OGradient: 40–70% A in 30 min, then
hold at 70% A for 5 minFlow Rate: 1 mL/minInj. Volume: 10 µLDetection: ELSD
Figure 17. Separation of different polyethylene glycols.
(B) 0.1 M NH4OAc, pH 5.4Gradient: 25–80% A in 30 min,
then hold at 80% A for 15 minTemperature: 30 °CFlow Rate: 1 mL/minInj. Volume: 5 µLDetection: ELSD, UVSample Prep: Dilute 10× with 70% acetonitrile,
then filtered through 0.2-µm membrane
Analysis of Surfactants in ConsumerProducts
Figures 18–22 demonstrate theapplicability of the Acclaim Surfactantcolumn for analyzing a variety ofconsumer products, such as shampoo,laundry detergent, dish washing liquid,mouthwash, and fabric softener.
Reproducible ManufacturingTo meet the exacting needs of our
customers, each Acclaim Surfactantcolumn is manufactured to stringentspecifications to ensure column-to-column reproducibility. Each column isshipped with a lot validation sheetshowing the test results and specifica-tions for the lot of bonded silica packedinto the column. In addition, eachcolumn is individually tested andshipped with an individual test chro-matogram validating the columnperformance, with respect to selectivity,capacity, and efficiency.
(B) 0.1 M NH4OAc, pH 5.4Gradient: 25–80% A in 30 min, then hold at 80% A for 10 minTemperature: 30 °CFlow Rate: 1 mL/minInj. Volume: 10 µLDetection: ELSD, UVSample Prep: Dilute 10× with 70% acetonitrile,
To order in the U.S., call (800) 346-6390 or contact the Dionex Regional Officenearest you. Outside the U.S., order through your local Dionex office or distribu-tor. Refer to the following part numbers.
Acclaim and AAMS are registered trademarks of Dionex Corporation.
Dionex Corporation Dionex Corporation Dionex U.S. Regional Offices Dionex International Subsidiaries1228 Titan Way Salt Lake City Technical Center Sunnyvale, CA (408) 737-8522 Australia 61 (2) 9420 5233 Austria (01) 616 51 25 Belgium (03) 3-353 42 94 Canada (905) 844-9650 China (852) 2428 3282P.O. Box 3603 1515 West 2200 South, Suite A Westmont, IL (630) 789-3660 Denmark 36 36 90 90 France 01 39 30 01 10 Germany 06126-991-0 Italy (06) 66 51 50 52 Japan (06) 6885-1213 Korea 82 2 2653 2580Sunnyvale, CA Salt Lake City, UT Houston, TX (281) 847-5652 The Netherlands (0161) 43 43 03 Switzerland (062) 205 99 66 United Kingdom (01276) 69172294088-3603 84119-1484 Atlanta, GA (770) 432-8100 * Designed, developed, and manufactured under an NSAI registered ISO 9001 Quality System.(408) 737-0700 (801) 972-9292 Marlton, NJ (856) 596-06009