- Method-specific performance for extractable petroleum hydrocarbon (EPH) analysis of soil and water samples.
- Complete separation of aliphatic and aromatic compounds into distinct fractions.
- Guaranteed background level under the strict reporting limits of MA and NJ EPH methods.
- Superior lot-to-lot reproducibility and storage stability ensured by rigorous QC testing and moisture-resistant packaging.
- Available in two formats: 5 g bed for higher loading capacity and 2 g bed for automated systems, time-saving, and solvent reduction.
Aliphatic Fraction
| Format | Lot # | Average ppm (n = 3) | |
| Region 1 (C9 – C18) |
Region 2 (C18 – C36) |
||
| 2 g | 1 | 3.2 | 2.5 |
| 2 | 3.7 | 2.9 | |
| 5 g | 1 | 13.2 | 17.3 |
| 2 | 11.3 | 16.4 | |
Restek aliphatic quality limits: <35 ppm each region
Aromatic Fraction
| Format | Lot # | Average ppm C9-C36 (n = 3) |
| 2 g | 1 | 9.5 |
| 2 | 9.5 | |
| 5 g | 1 | 34.2 |
| 2 | 35.6 |
Restek aromatic quality limits: <50 ppm
For 5 g Cartridges: Column: Rxi-5ms, 30 m, 0.32 mm ID, 0.25 μm (cat.# 13424); Sample: MA EPH surrogate spike mix (cat.# 31479); Conc.: 5 μg/mL; Injection Inj. Vol.: 1 μL splitless (hold 1 min); Liner: Restek Premium 4.0 mm ID cyclo double taper inlet liner (cat.# 23310); Inj. Temp.: 300 °C; Purge Flow: 50 mL/min; Oven Temp.: 40 °C (hold 1 min) to 300 °C at 12 °C/min to 330 °C at 6 °C/min; Carrier Gas: He, constant flow; Flow Rate.: 2 mL/min; Linear Velocity: 41.0 cm/sec @ 40 °C; Dead Time: 1.12 min @ 40 °C; Detector: FID @ 330 °C; Make-up Gas Flow Rate: 45 mL/min; Make-up Gas Type: N₂ Hydrogen flow: 40 mL/min; Air flow: 450 mL/min; Data Rate: 50 Hz Instrument: Agilent 7890B GC; Notes: The area of the surrogate peak was excluded from the calculated total extracted background value.
For 2 g Cartridges: Column: Rxi-5ms, 30 m, 0.25 mm ID, 0.25 μm (cat.# 13423); Sample: MA EPH surrogate spike mix (cat.# 31479); Conc.: 5 μg/mL; Injection Inj. Vol.: 1 μL splitless; Liner: Topaz single taper inlet liner with wool (cat.# 23303); Inj. Temp.: 250 °C; Purge Flow: 50 mL/min; Oven Temp.: 40 °C (hold 1 min) to 300 °C at 12 °C/min to 330 °C at 6 °C/min; Carrier Gas: He, constant flow; Flow Rate.: 2 mL/min; Linear Velocity: 41.0 cm/sec @ 40 °C; Dead Time: 1.12 min @ 40 °C; Detector: FID @ 330 °C; Make-up Gas Flow Rate: 45 mL/min; Make-up Gas Type: N₂ Hydrogen flow: 40 mL/min; Air flow: 450 mL/min; Data Rate: 50 Hz Instrument: Agilent 7890B GC; Notes: The area of the surrogate peak was excluded from the calculated total extracted background value.
No background, no problems.
Resprep EPH cartridges are guaranteed clean—we certify our background levels will always meet method requirements.
Same High-Performance Silica Now Available in Two Formats
- Use 5 g bed for higher loading capacity.
- Use 2 g bed for automated systems, time-saving, and solvent reduction.
Table I: Whether you use 5 g or 2 g formats, Resprep EPH fractionation SPE cartridges deliver accurate results consistently, even for the compounds most critical to method requirements as shown below.
Aliphatic Fraction
| 5 g Cartridges | 2 g Cartridges | ||||
| Compound | Function | Average % Recovery |
%RSD | Average % Recovery |
%RSD |
| Nonane (C9) | Most-retained aliphatic | 109.1 | 2.1 | 102.8 | 0.2 |
| 1- Chlorooctadecane | Surrogate | 107.0 | 0.6 | 89.8 | 0.4 |
| Octacosane (C28) | Aliphatic loading capacity probe | 109.2 | 1.0 | 101.6 | 0.0 |
| Tetracontane (C40) | Least-retained aliphatic | 106.8 | 0.6 | 100.7 | 0.1 |
Aromatic Fraction
| 5 g Cartridges | 2 g Cartridges | ||||
| Compound | Function | Average % Recovery |
%RSD | Average % Recovery |
%RSD |
| 1,2,3-Trimethylbenzene | Least-retained aromatic | 85.3 | 6.7 | 101.9 | 0.5 |
| Naphthalene | Breakthrough probe | 86.6 | 6.8 | 101.5 | 0.5 |
| 2-Methylnaphthalene | Breakthrough probe | 86.6 | 6.7 | 101.6 | 0.5 |
| 2-Fluorobiphenyl | Surrogate | 86.4 | 6.7 | 101.2 | 0.5 |
| 2-Bromonaphthalene | Surrogate | 86.2 | 6.7 | 101.7 | 0.5 |
| Phenanthrene | Aromatic loading capacity probe | 86.2 | 6.7 | 101.4 | 0.6 |
| o-Terphenyl | Surrogate | 86.2 | 6.7 | 99.7 | 0.4 |
| Dibenzo(a,h)anthracene | Most-retained aromatic | 82.2 | 7.7 | 99.5 | 0.5 |
Fortified concentrations for all fractions were prepared per gram silica and were 800 ppm (C28 and phenanthrene) and 40 ppm (all other compounds) after accounting for the amount of silica in each cartridge format (n = 3). Method requirements: MA EPH and NJ EPH analyte recovery 40%–140%; Texas EPH analyte recovery 60%–140% and surrogate recovery 70%–130%.
Which Cartridge Format do I Need?
Table II: If your samples don’t require a higher loading capacity, you can save time and reduce solvent consumption by using 2 g cartridges instead of 5 g cartridges.
Solvent Consumption Comparison
| Extraction Steps | Solvent Consumption (mL) | ||
| 5 g Cartridge | 2 g Cartridge | ||
| Cartridge conditioning | Dichloromethane | 6 | 3 |
| Hexane | 15 | 5 | |
| Aliphatic fraction | Sample | 1 | 1 |
| Hexane | 19 | 5 | |
| Aromatic fraction | Dichloromethane | 20 | 6 |
| Total solvent used (mL) | 60 | 20 | |
| Total chlorinated solvent used (mL) | 26 | 9 | |
| Reduce solvent waste by ~66%! | |||
Time-Saving Comparison
| Extraction Steps | Solvent Consumption (mL) | ||
| 5 g Cartridge | 2 g Cartridge | ||
| Cartridge conditioning | Dichloromethane (5-min hold) | 8 | 6.5 |
| Hexane | 7.5 | 2.5 | |
| Aliphatic fraction | Sample loading | 0.5 | 0.5 |
| Hexane | 9 | 2.5 | |
| Aromatic fraction | Dichloromethane | 10 | 3 |
| Concentration time | Two fractions | 60 | 15 |
| Miscellaneous steps | Adding solvent, transferring glassware | 8 | 8 |
| Total process time | 103 min | 38 min | |
| Save over an hour of sample prep time! | |||
No-risk, no-obligation trial.Free samples of Resprep solid phase extraction (SPE) tubes are available. Contact us or your local Restek representative to request yours.
