Samples were injected in splitless mode at an initial oven temperature of 50 C and an ̊ injector temperature of 250 C with helium as the carrier gas. The oven temperature was ̊ ramped at 15 C min to 120 C and then 3.5 C min to 300 C before holding at ̊ ‾1 ̊ ̊ ‾1 ̊ 300 C for 25 min. For quantification, the base peak area for individual PAH ̊ compounds was adjusted relative to the amount of internal standard added (refinement of EPA Method 8270D). Acidified sediments were sent to another lab where each station was analyzed for the percent organic carbon in each sample. The data was normalized to the percent organic carbon in the samples. Purification and GC-FID/GC-MS analysis of n-alkanes Solid phase extraction (SPE) was performed on the total lipid extracts for sediments and crab tissue using Strata SI-1 Silica (55um, 70A) Teflon-coated SPE columns (500 mg 3 mL Phenomenex) to purify the sample for n-alkanes. The alkane fraction was then ‾1, concentrated using nitrogen gas and transferred three times to a 4 mL amber vial using hexane. Nitrogen gas was used again to concentrate the alkane fraction followed by a dilution to 200 µL using hexane which was transferred to auto-sampler vials. N-alkanes were quantified by capillary GC using an Agilent 7890A Network GC system with flame ionization detection (GC-FID). The GC column and temperature program was similar to that described above for the PAH analysis. Base peak area of n-alkanes was adjusted relative to the known concentration of perdeuterated internal standard added Alkanes were identified in full-scan mode by GC-MS. Quality assurance and quality control
Samples were injected in splitless mode at an initial oven temperature of 50 ̊ C and an injector temperature of 250 ̊ C with helium as the carrier gas. The oven temperature was ramped at 15 ̊ C min ‾1 to 120 ̊ C and then 3.5 ̊ C min ‾1 to 300 ̊ C before holding at 300 ̊ C for 25 min. For quantification, the base peak area for individual PAH compounds was adjusted relative to the amount of internal standard added (refinement of EPA Method 8270D). Acidified sediments were sent to another lab where each station was analyzed for the percent organic carbon in each sample. The data was normalized to the percent organic carbon in the samples. Purification and GC-FID/GC-MS analysis of n-alkanes Solid phase extraction (SPE) was performed on the total lipid extracts for sediments and crab tissue using Strata SI-1 Silica (55um, 70A) Teflon-coated SPE columns (500 mg 3 mL ‾1, Phenomenex) to purify the sample for n-alkanes. The alkane fraction was then concentrated using nitrogen gas and transferred three times to a 4 mL amber vial using hexane. Nitrogen gas was used again to concentrate the alkane fraction followed by a dilution to 200 µL using hexane which was transferred to auto-sampler vials. N-alkanes were quantified by capillary GC using an Agilent 7890A Network GC system with flame ionization detection (GC-FID). The GC column and temperature program was similar to that described above for the PAH analysis. Base peak area of n-alkanes was adjusted relative to the known concentration of perdeuterated internal standard added Alkanes were identified in full-scan mode by GC-MS. Quality assurance and quality control
REU-Final-Paper.docx