Environmental

Rtx®-Dioxin2 columns have higher temperature stability (340 °C) than other confirmation columns and also provide isomer specificity for both 2,3,7,8-TCDD and 2,3,7,8-TCDF in a single column. These attributes allowed the Maxxam Analytics HR-MS group to make productivity improvements that resulted their being honored with a Kaizen award. (PDF - 691kB)

Analyze volatile compounds and polar analytes with greater confidence using Rxi®-624Sil MS columns. Optimized selectivity, higher inertness, and lower bleed result in reliable separations and accurate, trace-level determinations. Includes environmental and pharmaceutical applications. (PDF - 3111kB)

This 4-page newsletter includes an analysis of Massachusetts DEP air-phase petroleum hydrocarbons, as well as an update on the U.S. EPA Photochemical Assessment Monitoring Stations (PAMS) program. Also features Tedlar® bags and air canisters. (PDF - 774kB)

Concurrent solvent recondensation large volume splitless injection (CSR-LVSI) GC/MS is used here for analyzing pesticides and brominated flame retardants in drinking water based on EPA Method 527. CSR-LVSI allows a time-consuming sample extract concentration step to be eliminated, but can also be used with extract concentration for lower detection limits.

This 4-page newsletter includes an analysis of naphthalene along with TO-15 volatiles, as well as an innovative customer application for verifying sample port integrity during soil vapor intrusion monitoring. Also features air canisters and new air sampling products. (PDF - 337kB)

Semivolatiles are typically analyzed using splitless injection, but this approach results in slow analysis times and significant variability. In contrast, using split injection under the conditions established here allows faster sample throughput and increased repeatability.

Rxi® GC columns deliver more accurate, reliable trace-level results than any other fused silica column on the market. Take variation out of the equation and lower detection limits with highly inert, low bleed Rxi® gas chromatography columns. (PDF - 1929kB)

Confirming sample port integrity with a leak detector is a simple, cost-effective alternative to lab analysis of tracer gas in vapor intrusion VOC samples. Prevent resampling of soil vapors by confirming sample port integrity in the field prior to sampling.

Get improved resolution, faster analyses, and less downtime by using Rtx®-CLPesticides and Rtx®-CLPesticides2 columns for multiple GC/ECD methods. Instead of changing columns between methods, you can save time by analyzing chlorinated pesticides, PCBs, herbicides, and other halogenated compounds on a single column set. Rtx®-CLPesticides and Rtx®-CLPesticides2 columns have a unique selectivity and outperform other column sets offered specifically for multiple GC/ECD methods.

Ambient air sampling involves collecting a representative sample of ambient air for analysis. There are two general approaches: 1) “whole air” sampling with canisters or Tedlar® bags and 2) “in-field concentration” sampling using sorbent tubes or cold traps. In this guide, we focus on collecting whole air samples in canisters, a flexible technique with many applications. (PDF - 1408kB)

Analytical conditions for GC analysis of volatile organic compounds have been optimized to ensure good resolution of critical pairs, while maximizing sample throughput. Rxi^®-624Sil MS columns are shown to outperform other 624s.

Gas sampling bags can be a cost-effective alternative to canisters and thermal desorption tubes for many air monitoring applications, including VOCs and permanent gases. This 4-page flyer provides general guidelines, product specifications, and recommended applications. (PDF - 953kB)

Polycyclic aromatic hydrocarbons (PAHs) are common environmental pollutants, affecting air, water, and soil quality. Although naturally occurring, human impact has created a steady increase in environmental levels of PAHs and their byproducts. PAHs are typically formed through the incomplete combustion of organic materials, such as wood, coal, and oil, but are also used in manufacturing of some medicines, plastics, and pesticides. Many PAHs are known or suspected carcinogens. The United States Environmental Protection Agency currently lists and mandates testing of the 16 PAHs they deem most hazardous. (PDF - 226kB)

Semivolatiles methods, such as EPA Method 8270, place stringent demands on gas chromatography (GC) columns. Here we demonstrate the performance of Rxi^®-5Sil MS columns for semivolatiles analysis in terms of bleed, efficiency, and activity. Excellent sensitivity and resolution are seen, even for difficult PAHs such as benzo(b)fluoranthene & benzo(k)fluoranthene, and indeno(1,2,3-cd)pyrene and dibenzo(a,h)anthracene. Both basic and acidic compounds show good response even at low levels. (PDF - 620kB)

New Semivolatiles Wool, pre-packed in Restek liners, is designed specifically for semivolatiles analysis and result in more accurate results at lower levels, compared to similar products.

Sample throughput for haloacetic acids in drinking water can be increased significantly using Rtx^®-CLPesticides/Rtx^®-CLPesticides2 columns. Target HAAs were fully resolved in under 13 minutes.

Direct injections of water-based samples, such as samples containing ethylene glycol, can cause poor peak shape, sample carryover, and FID flameout. Avoid these problems using the chromatography tips described here. (PDF - 203kB)

Sample throughput for PBDE analysis can be significantly increased using a 15m Rtx^®-1614 column. Excellent responses and peak shapes are obtained for all congeners, including BDE-209, in just 20 minutes.

Conserve solvent, ensure cleaner extracts, and obtain high recovery of target pesticides by using graphitized carbon-based CarboPrep^® SPE tubes to prepare samples for chlorinated pesticides analysis. (PDF - 676kB)

As labs operate in an extremely competitive market, the demand for more sensitive multiresidue pesticide methods is increasing. Here we demonstrate linearity down to 10pg on-column for a wide range of pesticides differing in volatility, compound class, and degree of activity. The inertness of the Rxi^®-5Sil MS column ensures linear performance and more accurate low level quantification for multiresidue pesticide methods.

Programmable temperature vaporization inlets are versatile, yet normally do not accommodate on-column injection. Now, using a PTV On-Column liner, the capabilities of PTV can be expanded to include true on-column injections.

The Rtx^®-Dioxin2 column has a unique selectivity for dioxins and furans, including specificity for 2,3,7,8-TCDD and 2,3,7,8-TCDF. Here we characterize all 136 tetra- through octachlorine dioxins and furans and define all possible coelutions. While commonly used cyanopropyl columns are limited by a low maximum operating temperature of 240°C, the Rtx^®-Dioxin2 column is stable up to 340°C, extending column lifetime and improving the analyses of dioxins and furans.

Restek develops reference standards for underground storage tank testing. This flyer includes UST fuel composite standards, single source fuel standards, fuel surrogate & internal standards, & standards blended for specific state methods. (PDF - 438kB)

Here we analyze polycyclic (polynuclear) aromatic hydrocarbons (PAHs) from the US EPA, European Union (EU), and Portugal lists by UHPLC and HPLC. Procedures shown use two optimized stationary phases (Pinnacle^® DB PAH and Pinnacle^® II PAH) and provide 3.5 to 6 minute analyses, allowing labs to achieve significantly faster sample throughput.

An optimized EPA Method 535 procedure offers superior sensitivity for the ethanesulfonic acid (ESA) and oxanilic acid (OA) degradates of chloroacetanilide herbicides alachlor, acetochlor, and metolachlor. Alachlor ESA and acetochlor ESA isomers are reliably resolved, and the procedure is simplified with a full line of Method 535 products, including reference standards, solid phase extraction cartridges, and HPLC columns.

Thermal desorption is now recognized as the technique of choice for environmental air monitoring and occupational health and safety. This 28-page publication from Markes International Ltd. presents several real world thermal desorption applications. (PDF - 1137kB)

The use of carbon disulfide (CS₂) extraction as an air monitoring method for vapor-phase organic compounds (VOCs) is fundamentally limited with respect to detection limits. Thermal desorption (TD) is a complementary gas extraction technique whereby sorbent tubes are heated in a flow of carrier gas. Trapped vapors desorb from the sample tubes into the gas stream and are transferred into the GC/MS analyzer. Here, we summarize the key advantages of thermal desorption versus solvent extraction.

The Rtx^®-CLPesticides and Rtx^®-CLPesticides2 column pair is an excellent choice for chlorophenoxyacid herbicide analysis. Now, with an optimized film thickness for the 0.32mm ID version, this difficult analysis can be made in less than 13 minutes on both the primary and confirmation columns. Near baseline resolution is achieved for all analytes except for bentazon/picloram on the Rtx^®-CLPesticides column; however, this pair is fully resolved on the Rtx^®-CLPesticides2.

This 2-page note describes the features and benefits of our popular TO-Can^® air monitoring canisters (SUMMA^® can equivalents), our new canister air sampling timer, and our convenient, reliable passive air sampling kits. (PDF - 206kB)

Analyses of chlorinated pesticides can be difficult because samples often are contaminated with non-target compounds (e.g., lipids), and the method can require rigorous quality control. Our 24-page guide covers sample extraction methodology, sample cleanup, and chromatography. A chromatographic analysis of widely used chlorinated herbicides also is illustrated. One of our most popular technical guides. (PDF - 4062kB)

Semivolatiles methods, such as EPA Method 8270, place stringent demands on gas chromatography (GC) columns. Here we demonstrate the performance of Rxi^®-5Sil MS columns for semivolatiles analysis in terms of bleed, efficiency, and activity. Excellent sensitivity and resolution are seen, even for difficult PAHs such as benzo(b)fluoranthene & benzo(k)fluoranthene, and indeno(1,2,3-cd)pyrene and dibenzo(a,h)anthracene. Both basic and acidic compounds show good response even at low levels.

The new Allure^® AK HPLC column was developed specifically for the analysis of aldehydes and ketones, including the 13 carbonyl compounds specified in the California Air Resources Board (CARB) Method 1004. The data shown in this article demonstrate excellent resolution, even of buteraldehyde and methyl ethyl ketone (MEK), in less than 12 minutes using a 200mm Allure^® AK HPLC column.

Semivolatiles methods, such as EPA Method 8270, place stringent demands on gas chromatography (GC) columns. Here we evaluate the performance of Rxi^®-5Sil MS columns for semivolatiles analysis in terms of bleed, efficiency, and activity. We demonstrate excellent sensitivity and resolution, even for difficult PAHs such as benzo(b)fluoranthene & benzo(k)fluoranthene, and indeno(1,2,3-cd)pyrene and dibenzo(a,h)anthracene. Both basic and acidic compounds show good response even at low levels.

Rtx^®-CLPesticides and Rtx^®-CLPesticides2 columns are ideal for multiple environmental ECD methods. Here we demonstrate the effectiveness of this column pair for chlorinated pesticides, PCBs as Aroclors, and chlorinated herbicides. (PDF - 8005kB)

Polynuclear aromatic hydrocarbons are a significant, and wide-spread, source of pollution. The US EPA mandates testing of the 16 PAHs they designate as most hazardous; the target list in other countries is expanding and includes new compounds that are difficult to separate. Here we demonstrate the ability of the Rxi^®-17 column to effectively resolve dibenzo pyrene isomers, as well as to separate benzo(j)fluoranthene from benzo(b)fluoranthene and benzo(k)fluoranthene.

Increasing sample throughput is an effective way to reduce operating costs for environmental labs. Here we introduce new film thicknesses for the Rtx^®-CLPesticide and Rtx^®-CLPesticide2 GC columns, optimized for complete separations and short analysis times. Using these new columns, all US EPA Method 8081 organochlorine pesticides are resolved in <9 min. We also show complete separation of these compounds in <5 min. using these columns and a Gerstel MACH column heating system.

Liner choice is a critical decision in semivolatiles analysis. Liners containing wool packing are recommended to minimize molecular weight discrimination. Attributes of different types of liners, including the Drilled Uniliner^®, are discussed.

Nineteen polycyclic aromatic hydrocarbons (PAHs), including benzo(b) and benzo(j)fluoranthene, were fully resolved using a Pinnacle^® II PAH column. Greater sensitivity was achieved by coupling UV and fluorescence detection. This HPLC method offers improved resolution compared to standard GC techniques.

Switching to a methanol-based mobile phase for polycyclic aromatic hydrocarbon analysis—using the method shown here—is an effective way to save money by reducing acetonitrile consumption. (PDF - 119kB)

We developed the 20m x 0.18mm x 0.30µm Rxi^®-5ms column to balance the demand for shorter analysis times with the need to maintain both column capacity and column efficiency. Here we establish conditions for eluting more than 90 semivolatiles, including 7 surrogates and 6 internal standards, in less than 12 minutes. Benzo(b) and benzo(k)fluoranthene were resolved well and sample throughput was improved by 75%. This highly inert, low bleed column is ideal for GC/MS analysis.

This 4-page newsletter includes new applications for monitoring total reduced sulfurs at ppbv levels and air can sampling of microbial volatile organic compound (VOC) for testing by GC/MS. Also features new air sampling products. (PDF - 295kB)

This flyer give an overview of TD sampling and describes many applications that can be sampled using this versatile technique. Includes a comparison of tube and canister sampling, to help you determine which VOC sampling technique is best for you. (PDF - 177kB)

Developed through collaboration with scientists at AB/MDS Sciex, this analysis allows complete resolution of paraquat and diquat with a simple, isocratic mobile phase. It is significantly faster than conventional methodologies and, with detection limits of 5ppb for paraquat or 0.1ppb for diquat, sensitivity is superior — without preconcentration.

Using this new column, resolution and peak shapes for 88 semivolatile compounds commonly analyzed in drinking water are exceptionally good at 10ng each on column. Because the Rxi®-5ms column performs well with analytes in a diverse range of chemical classes, we highly recommend it for analyzing complex mixtures of semivolatiles.

Exceptional inertness and ultra-low bleed enable an Rxi^®-5ms column to resolve sub-1ng quantities of acidic or basic analytes under a single set of conditions. In this example analysis, an Rxi^®-5ms column separated 93 target analytes in US EPA Method 8270D in less than 18 minutes.

The newest members of our new line of Rxi^® columns, Rxi^®-1ms columns, offer the same outstanding inertness, ultra-low bleed, and batch-to-batch reproducibility as our Rxi^®-5ms columns. Rxi^®-1ms columns provide excellent selectivity and symmetric peaks for the diverse chemicals that can make up a semivolatiles sample.

New manufacturing processes for our Massachusetts TPH solid phase extraction cartridges reduce extractable contaminants almost to blank levels, and assure more reliable fractionation of aliphatics from aromatics. Large, uniform lots of silica reduce the frequency of verifying fractionation results.

An Rtx^®-VMS column provides rapid, baseline resolution of most volatile analytes in the CLP OLM 04.1 analysis for groundwaters or drinking waters from Superfund sites. A particularly challenging stipulation of the method, 90% resolution of the gaseous components, is easily attained.