[Skip to Content](https://www.sigmaaldrich.com#main-content) [![MilliporeSigma](https://www.sigmaaldrich.com/static/logos/purple/millipore_sigma.svg)](https://www.sigmaaldrich.com/US/en) Products Cart0 USEN Products ProductsApplicationsServicesResourcesSupport [Login / Register](https://www.sigmaaldrich.com/oidc-sign-in) [Order Lookup](https://www.sigmaaldrich.com/US/en/order-lookup) [Quick Order](https://www.sigmaaldrich.com/US/en/quick-order) Cart0 [Home](https://www.sigmaaldrich.com/US/en)[Solid Phase Microextraction (SPME)](https://www.sigmaaldrich.com/US/en/applications/analytical-chemistry/sample-preparation/solid-phase-microextraction)Rugged SPME Sampling # Rugged SPME Sampling ## Elevate your fiber performance with nitinol-core SPME fibers SPME fibers with Carboxen®/Polydimethylsiloxane (CAR/PDMS) and Polydimethylsiloxane/ Divinylbenzene (PDMS/DVB) coatings are now available on a nitinol core (NIT) in a SS assembly for improved fiber performance. Selectivity of the CAR/PDMS and PDMS/DVB SPME fibers has been maintained for seamless transition of methods from fused-silica core (FS) fibers to the improved NIT technology. NIT fibers offer the following benefits: - Enhanced fiber reproducibility - Greater fiber durability - Maintained selectivity for method consistency - Core inertness to ensure analyte stability [Download App Note](https://www.sigmaaldrich.com/deepweb/assets/sigmaaldrich/marketing/global/documents/360/163/nit-reproducibility-wp6311en-ms.pdf) ![Elevate your fiber performance with Supelco® nitinol-core SPME fibers](https://www.sigmaaldrich.com/content/dam/cms-commons/sigmaaldrich/marketing/global/images/technical-documents/articles/analytical-chemistry/solid-phase-microextraction/nitionl-core-spme-fibers.jpg "Elevate your fiber performance with nitinol-core SPME fibers") ## Improved Lot-to-Lot and Fiber-to-Fiber Reproducibility The nitinol-core SPME manufacturing process has been optimized to enhance lot-to-lot and fiber-to-fiber reproducibility. This enhanced reproducibility stems from more stringent coating specifications reducing fiber variation significantly in particular for fiber diameter/coating thickness. The improvements provide enhanced precision of chromatographic results. The NIT CAR/PDMS and NIT PDMS/DVB fibers were compared to FS versions of the same fiber chemistry following the methodology detailed in __Table 1__ and visually represented in __Figure 1__. The __Figure 2__ shows that both the NIT CAR/PDMS fibers and NIT PDMS/DVB fibers exhibit significant reduction in intra-lot variability and inter-lot variability as compared to the FS version. | | | |------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | SPME Conditions | | | __Sample:__ | Isobutyl acetate 0.375 ug/mL, n-butanol 275 ug/mL, o-xylene 0.1825 ug/mL, and 0.175 ug/mL toluene in 25% NaCl water, pH 7 with 0.05 M phosphate buffer (double concentration for PDMS-DVB Fibers) in 10 mL screw capped vial | | __Fiber:__ | CAR/PDMS & PDMS/DVB on Nitinol and fused silica cores | | __Autosampler:__ | Gerstel MPS 2 with MFX feature for exchanging fibers | | __Sample Incubation:__ | 2 min. at 40 °C | | __Extraction:__ | headspace 40 °C, 10 min with agitation at 200 rpm | | __Desorption:__ | 3 min at 270 °C | | __Post Condition:__ | 2 min at 300 °C in fiber conditioning Station | | | | |---------------------|------------------------------------------------------------------------------------------------------| | GC Conditions | | | __Column:__ | SUPELCOWAX® 10   30 m x 0.25 mm, 0.5 µm (24284) | | __Oven:__ | 45 °C (hold 2 min) to 65 °C at 6 °C/min to 100 °C at 10 °C/min to 150 °C at 15 °C/min (hold 0.5 min) | | __Carrier Gas:__ | Helium, 1 mL/min constant flow | | __Injection port:__ | 270 °C, with 0.75 mm ID liner | | __Injection:__ | Splitless for 0.5 min at 1 mL/min then vent at 50 mL/min | | __Detector:__ | FID at 300 °C | Table 1.Analytical Testing Method for Comparison of NIT and FS Fiber Inter-lot and Intra-lot Repeatability ![Representative Chromatogram of the Analytical Testing Method Depicted on a CAR/PDMS NIT Fiber](https://www.sigmaaldrich.com/content/dam/cms-commons/sigmaaldrich/marketing/global/images/technical-documents/articles/analytical-chemistry/solid-phase-microextraction/car-pdms-nit-fiber-chromatogram.jpg "Representative Chromatogram of the Analytical Testing Method Depicted on a CAR/PDMS NIT Fiber") __Figure 1.__Representative Chromatogram of the Analytical Testing Method Depicted on a CAR/PDMS NIT Fiber ![Inter-lot and Intra-lot Reproducibility Testing Comparing NIT and FS SPME Fibers](https://www.sigmaaldrich.com/content/dam/cms-commons/sigmaaldrich/marketing/global/images/technical-documents/articles/analytical-chemistry/solid-phase-microextraction/reproducibility-testing-nit-fs-spme-fibers-carbon.jpg "Inter-lot and Intra-lot Reproducibility Testing Comparing NIT and FS SPME Fibers") __Figure 2.__Inter-lot and Intra-lot Reproducibility Testing Comparing NIT and FS SPME Fibers ## Greater SPME Fiber Durability NIT provides improved durability over FS fibers. In this comparison, the NIT and FS fibers were subjected to a flexibility test to determine fiber strength/mechanical stability. Three FS core fiber and three NIT core fiber assemblies of each coating were flexed from 0° to 180° as indicated in __Figure 3__. NIT fibers were flexed to 180° without breaking or permanently kinking regardless of coating type. __Figure 4__ shows a 90° flexion of a NIT fiber. FS fiber assemblies regardless of coating type broke off at the point of attachment when flexed between 40° and 50°. Despite the increase in mechanical stability it is still recommended to minimize the mechanical stress to the coated fibers as much as possible. ![Flexion Points for Durability Test](https://www.sigmaaldrich.com/content/dam/cms-commons/sigmaaldrich/marketing/global/images/technical-documents/articles/analytical-chemistry/solid-phase-microextraction/flexion-points-durability-test.jpg "Flexion Points for Durability Test") __Figure 3.__Flexion Points for Durability Test ![90° flexion of a NIT fiber](https://www.sigmaaldrich.com/content/dam/cms-commons/sigmaaldrich/marketing/global/images/technical-documents/articles/analytical-chemistry/solid-phase-microextraction/degree-flexion-nit-fiber.jpg "90° flexion of a NIT fiber") __Figure 4.__90° flexion of a NIT fiber ## SPME Coating Selectivity and Core Inertness Maintained To facilitate seamless transfer of methods from FS fibers to the NIT fibers of the same coating type, selectivity and inertness were compared to ensure consistency using two sets of indicator compounds: alkyl halides and small short chain amines. Comparisons were performed on four lots of CAR/PDMS and PDMS/DVB of each core type to confirm repeatability of results. The selectivity of CAR/PDMS and PDMS/DVB fibers for the alkyl halides on each core type was examined through a comparison of analyte response rates using the method outlined in __Table 2__. __Figure 5__ shows that coating selectivity is maintained for both the CAR/PDMS and PDMS/DVB chemistries for the alkyl halides regardless of core type. The difference between responses of halogenated alkanes extracted using coatings on NIT and FS cores was less than 3% for all coatings. Because alkyl halides are known to breakdown at elevated temperatures upon interaction with exposed active sites, the inertness of the two fiber types was then investigated to ensure that no increase in degradation was taking place on the NIT fibers. Percent conversion of the studied alkyl halide to their corresponding alkene is displayed in __Figure 6__. For all analytes, which are known to be prone to degradation, NIT fibers exhibit equal or better preservation of sample for both coating types. Percent breakdown was also found to be correlated with temperature, as anticipated. Inertness and selectivity of the fibers was then compared for more polar compounds using the series of short chain amines. Short chain amines also tend to be problematic analytes due to their reactivity with metal which results in oxidative degradation that intensifies at elevated temperatures. The analyte response of each amine was divided by the internal standard, n-propanol, which is stable under these conditions, to examine amine breakdown or irreversible adsorption. If breakdown were to occur, the ratio would be lower on a more active core. The chromatogram and ratios depicted in __Figure 7__ indicate that the selectivity and core inertness is maintained between the FS and NIT fibers for the amine series. The values are statistically the same at 5% RSD. | | | |--------------------|------------------------------------------------------------------------------| | SPME Conditions | | | __Sample:__ | Halogenated alkanes at 150 ug/mL in 4 mL water, 25% NaCl, pH 7 in 10 mL vial | | __Preincubation:__ | 2 min with agitation at 40 °C | | __Extraction:__ | Headspace, 10 min at 40 °C with agitation at 250 rpm using MPS II | | __Fibers:__ | CAR/PDMS & PDMS/DVB on Nitinol and fused silica cores | | __Desorption:__ | 3 min at 280 °C for CAR/PDMS and 230 °C for PDMS/DVB | | __Post Bake:__ | 2 min at 250 °C | | | | |------------------|-----------------------------------------------------------------------------------------| | GC-MS Conditions | | | Oven program: | 40 °C hold 2 min to 70 °C at 8 °C /min to 150 °C hold 3 min | | Column: | VOCOL® 30m x 0.25mm ID, 1.5 µm df (24205-U) | | Injector: | 280 °C for CAR/PDMS and 230 °C for PDMS/DVB, splitless open after 0.75 min at 30 mL/min | | Desorption: | 3 min at set injection temperatures | | Carrier Gas: | Helium, 1 mL/min constant flow | | Detector: | MSD-m/z 40-300 full scan | Table 2.Analytical Method for the GC Analysis of Alkyl Halides on NIT and FS Fibers ![Alkyl Halide Analyte Responses by Core Type and Coating](https://www.sigmaaldrich.com/content/dam/cms-commons/sigmaaldrich/marketing/global/images/technical-documents/articles/analytical-chemistry/solid-phase-microextraction/alkyl-halide-analyte-responses.jpg "Alkyl Halide Analyte Responses by Core Type and Coating") __Figure 5.__Alkyl Halide Analyte Responses by Core Type and Coating ![Core Inertness Study on the Breakdown of Alkyl Halides](https://www.sigmaaldrich.com/content/dam/cms-commons/sigmaaldrich/marketing/global/images/technical-documents/articles/analytical-chemistry/solid-phase-microextraction/alkyl-halide-breakdown-car-pdms.jpg "Core Inertness Study on the Breakdown of Alkyl Halides") __Figure 6.__Core Inertness Study on the Breakdown of Alkyl Halides ![alkyl halide breakdown pdms dvb nit fs fibers](https://www.sigmaaldrich.com/content/dam/cms-commons/sigmaaldrich/marketing/global/images/technical-documents/articles/analytical-chemistry/solid-phase-microextraction/alkyl-halide-breakdown-pdms-dvb-nit-fs-fibers.jpg "alkyl-halide breakdown pdms dvb nit fs fibers") | | | |-----------------|--------------------------------------------------------------------| | __Column:__ | SPB®-1 Sulfur (base deactivated), 30 m x 0.32 mm x 4.0 µm (24158) | | __Sample:__ | 1 ug/mL each in water with 25% NaCl, 0.05 M phosphate buffer pH 11 | | __Extraction:__ | 10 min immersion | | __Fibers:__ | PDMS/DVB Fused Silica & NIT cores | | __Desorb:__ | 3 min @ 250 °C | | __Oven:__ | 45 °C (1.5 min) to 80 °C at 8 °C/min to 200 °C at 20 °C/min | | __Injector:__ | 250 °C, splitless closed initial 0.75 min | | __Detector:__ | FID at 300 °C | ![Core Inertness and Analyte Response Comparison of Amines in Relation to n-Propanol on NIT and FS Fibers](https://www.sigmaaldrich.com/content/dam/cms-commons/sigmaaldrich/marketing/global/images/technical-documents/articles/analytical-chemistry/solid-phase-microextraction/core-inertness-analyte-response-comparison-amines-nit-fs-fibers.jpg "Core Inertness and Analyte Response Comparison of Amines in Relation to n-Propanol on NIT and FS Fibers") __Figure 7.__Core Inertness and Analyte Response Comparison of Amines in Relation to n-Propanol on NIT and FS Fibers ## Benefits of nitinol-core SPME fibers The nitinol-core SPME fibers show enhanced lot-to-lot as well as fiber-to-fiber reproducibility. The coating consistency has been optimized lending to an improvement in repeatability of analytical results. Durability of the fibers has been vastly increased by the NIT core allowing the fibers to handle 180° distortion. With these improvements, the selectivity and inertness of the CAR/PDMS or PDMS/DVB SPME FS fibers is maintained allowing simple transfer of methods from the FS version to the new NIT variety. Sampling Mode and Needle Size Fiber Coating and ThicknessFiber Core/ Assembly TypeHub DesciptionManual Holder/ (w/spring)Autosampler  23 Ga\*24 Ga\*23 Ga\*24 Ga* __Carboxen®/Polydimethylsiloxane (CAR/PDMS)__ 75 µm CAR/PDMSNIT/SSBlack Metallic[57901-U](https://www.sigmaaldrich.com/US/en/product/supelco/57901u)[57904-U](https://www.sigmaaldrich.com/US/en/product/supelco/57907u)[57907-U](https://www.sigmaaldrich.com/US/en/product/supelco/57907u)[57908-U](https://www.sigmaaldrich.com/US/en/product/supelco/57908u) __Polydimethylsiloxane/Divinylbenzene (PDMS/DVB)__ 65 µm PDMS/DVBNIT/SSBlue Metallic[57916-U](https://www.sigmaaldrich.com/US/en/product/supelco/57916u)[57921-U](https://www.sigmaaldrich.com/US/en/product/supelco/57921u)[57923-U](https://www.sigmaaldrich.com/US/en/product/supelco/57923u)[57931-U](https://www.sigmaaldrich.com/US/en/product/supelco/57931u) ## Materials Sorry, an unexpected error has occurred Response not successful: Received status code 500 __Related Articles__ - [Biodiesel](https://www.sigmaaldrich.com/US/en/technical-documents/technical-article/analytical-chemistry/gas-chromatography/biodiesel) - [Automated Solid Phase Microextraction (SPME) Sampling](https://www.sigmaaldrich.com/US/en/technical-documents/technical-article/analytical-chemistry/solid-phase-microextraction/automated-spme-sampling) - [Bioanalysis with SPME](https://www.sigmaaldrich.com/US/en/technical-documents/technical-article/analytical-chemistry/solid-phase-microextraction/bioanalysis-with-spme) - [BioSPME for Plasma Protein Binding Assay: Details of Method Development and Optimization](https://www.sigmaaldrich.com/US/en/technical-documents/technical-article/analytical-chemistry/solid-phase-microextraction/biospme-plasma-protein-binding-assay) - [Solid Phase Microextraction: Frequently Asked Questions](https://www.sigmaaldrich.com/US/en/technical-documents/technical-article/analytical-chemistry/solid-phase-microextraction/faq) - [GC/MS/MS Analysis of BPA in Energy Drink](https://www.sigmaaldrich.com/US/en/technical-documents/technical-article/analytical-chemistry/solid-phase-microextraction/gc-ms-ms-analysis-of-bisphenol-a-bpa-in-a-fruit-flavored-energy-drink-cla010218a) - [SPME Fiber Performance Tips for Volatiles & Semi-Volatiles](https://www.sigmaaldrich.com/US/en/technical-documents/technical-article/analytical-chemistry/solid-phase-microextraction/performance-tips) - [Analysis of Pesticides in Baby Food by Solid Phase Microextraction (SPME) Using a New Overcoated Fiber](https://www.sigmaaldrich.com/US/en/technical-documents/technical-article/analytical-chemistry/solid-phase-microextraction/pesticides-baby-food-spme) - [View More](https://www.sigmaaldrich.com/US/en/search/facet-search?focus=sitecontent&term=facet-search) [Download PDF](https://www.sigmaaldrich.com/deepweb/assets/sigmaaldrich/marketing/global/documents/342/648/nitinol-core-spme-fibers-ms.pdf) Top __Sign In To Continue__ To continue reading please sign in or create an account. 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