For detection of Polynuclear Aromatic Hydrocarbons (PAHs) (as phenanthrene) in soil. For testing in other matrices, please contact our technical support department at 1-800-544-8881.
Materials Required but Not Provided
SDI Sample Extraction Kit
(Part Number: A00160EA/A00160EB)
Procedural Notes and Precautions
- Prepare soil samples for analysis according to the procedure in the SDI Sample Extraction Kit Users Guide.
- After extraction and dilution of samples, follow the immunoassay procedure as described in the Rapid Assay PAH Test Kit User’s Guide.
- The initial 1.33x dilution described for water samples in Step 1 of “Collect/Store the Sample” does not need to be performed for soil samples.
A control solution at approximately 25 ppb (as phenanthrene) is provided with the PAH RaPID Assay Kit. It is recommended that it be included in every run and treated in the same manner as unknown samples. If running standard soil procedures an acceptable result should be 100 times the value stated on the control vial (i.e. 2.5 + or – 0.5 ppm) when the control results are corrected for the dilution factors (see Results section below).
Interpret soil sample results as described in the RaPID Assay PAH Test Kit procedure, accounting for the total dilution factor indicated in the table of the SDI Sample Extraction Kit Users Guide. Alternatively, program the RPA-1 Analyzer as listed below to automatically correct for this dilution factor.
1. The RPA-I photometer (provided in the Rapid Assay Accessory kit) can be used to calculate and store calibration curves. To obtain soil results from the PAH Rapid Assay test kit on the RPA-I the following parameter settings are recommended:
Data Reduct : Lin. Regression
Xformation : Ln/LogitB
Read Mode : Absorbance
Wavelength : 450 nm
Units : PPM
# Rgt Blk : 0
# of Cals : 4
# of Reps : 2
#1: 0.00 PPM
#2: 0.20 PPM
#3: 1.00 PPM
#4: 5.00 PPM
Range: 0.2 – 5 ppm
Rep. %CV: 10%
The PAH RaPID Assay does not differentiate between PAH and other related compounds. The table below shows compounds at the method detection limit (MDL) which is the lowest concentration of the compound in soil that can be picked up in the assay. The limit of quantitation (LOQ) is an approximate concentration required to yield a positive result at the lowest standard, this is the lowest concentration of the compound in soil that can be quantified in the assay. The IC50 is the concentration in soil required to inhibit one half of the color produced by the negative control. It is also used to calculate cross-reactivity values to similar compounds.
The Total PAHS (sum of 16 PAH compounds) of the indicated contaminant types in soil samples are expressed below, at each of the three kit calibrator (standard) levels, in units comparable to results from GC Method 8270 or HPLC Method 8310.
Range of Detection
The PAH RaPID Assay has a range of detection in soil of 0.2 ppm to 5 ppm (as phenanthrene) when used in conjunction with the SDI Sample Extraction Kit.
PAH recoveries will vary depending on soil type, retention mechanism, solvent and extraction apparatus used, length of extraction period and levels of potentially interfering substances in the soil.