Why JQ1 Can Impact Most Of Us
5, 50, and 250?ng/g (Table 3). Analysis of a NIST standard reference material performed over a period of several weeks illustrates the accuracy and precision of the method using certified reference material (Table 4). This analysis provided excellent recovery for total PAH (98%, n = 11) with high precision (7�C19% RSD) that meets the guidelines expressed in the NOAA reference method and National Institute of Standards and Technology Deepwater Horizon study [1, 26]. Only two PAH values, naphthalene and anthracene, were outside the target range. Naphthalene exhibited the highest variability (19% RSD) which may have been due to losses during the extra 10-minute shake in our QuEChERS procedure and the relatively high volatility of naphthalene. Although the value for fluorene is within range of the NIST standard reference material, the fluorene values reported in Table 4 were only detected using a 60?m column (n = 3) because JQ1 in vivo of coelution of other analytes, such as PCBs, that was difficult to separate using the shorter 30?m column. Anthracene was overestimated due to coelution of contaminants when a shorter GC separation was employed for the study. The presence of a coeluting contaminant in the stir bar extract was confirmed by comprehensive GC �� GC analysis on a Leco Pegasus 4D system (data not shown). All of the PAHs were detected, even anthracene, much below the lowest regulatory limits. The limits of detection for the PAHs were found to be 0.020?ppb and the limits of quantification 0.060?ppb, based on s/n ratios of 3?:?1 and 10?:?1, respectively. Table 4 Analysis on SRM mussel tissue. 3.4. Testing Additional R428 Matrices Since the SBSE method was successfully validated in both spiked oysters and in NIST standard reference material (mussel tissue) the method was repeated in other seafood matrices using croaker (a finfish) and shrimp. Table 5 shows the linear regression data with 1�C250?ng/g spiked tissues with mean r2 values from 0.9905�C0.9948 (n = 3). Also, percent recoveries ranged from 63.1 to 93.6% when croaker and shrimp were spiked with 50?ng/g of analyte, a concentration below the regulatory level of concern. Even though further inter- and intralaboratory studies are needed E-64 to fully test the utility of this new extraction procedure, these results with oysters, croaker, and shrimp show significant promise for increasing analytical capacity for assessing petroleum contamination in potentially impacted seafood. Table 5 Analysis of finfish and shrimp matrices, n = 3. The SBSE method is successful with difficult matrices, like seafood, by not only decreasing matrix interference, but also concentrating the analytes. The method and theory of SBSE has been described in detail elsewhere [27]. Briefly, the PDMS coating on the stir bar acts as an immobilized liquid into which apolar analytes in an aqueous matrix can partition.
