Glossary of Technical Terms, Acronyms, and Units of Measure

amu -- atomic mass unit. A measure of atomic mass which is equal to 1/12 of the mass of a carbon atom of mass 12.
Aroclor -- Aroclor is a trademark, registered to Monsanto Corporation, for naming mixtures of individual chlorinated biphenyls and chlorinated polyphenyls. Monsanto Corporation was the major producer of Aroclors from 1930 to 1977. Aroclors were used in a wide variety of applications, including dielectric fluids in capacitors and transformers, heat transfer fluids, hydraulic fluids, lubricating and cutting oils, and as additives in pesticides, paints, copying paper, carbonless copy paper, adhesives, sealants, and plastics. Each Aroclor is assigned a four digit number. The last two digits indicate the approximate percentage in weight of chlorine in the product, and the first two digits indicate the type of material as follows: 12 -- chlorinated biphenyls, 25 -- blend of chlorinated biphenyls and chlorinated terphenyls (75:25), 44 -- blend of chlorinated biphenyls and chlorinated terphenyls (60:40), and 54 -- chlorinated terphenyls.
Aroclor-based PCB concentration -- PCB analysis where calibration is based on one or more mixtures of Aroclors rather than on individual PCB congeners.
BHCs -- benzenehexachlorides, trade names for hexachlorocyclohexanes.
BZ # -- Ballschmiter and Zell number for a designated PCB congener.
CAS No. -- Chemical Abstracts Service Registry Number is a unique serial number assigned to a given compound. There is no inherent significance to the registry number.
congener -- a member of a series of structurally similar compounds.
DDD -- see DDT.
DDE -- see DDT.
DDI -- double-deionized, such as in double-deionized water.
DDT -- insecticide dichlorodiphenyltrichloroethane. DDT metabolites include DDD (dichlorodiphenyldichloroethane) and DDE (dichlorodiphenyldichloroethylene).
dioxin -- term commonly used to refer to a group of seven 2,3,7,8-substituted polychlorinated dibenzo[p]dioxin (PCDD) congeners and ten 2,3,7,8-substituted polychlorinated dibenzofuran (PCDF) congeners. When the number of chlorine atoms per molecule is four, the terms tetrachlorodibenzo[p]dioxin (TCDD) and tetrachlorodibenzofuran (TCDF) are often used. 2,3,7,8-TCDD is the most toxic of all PCDD and PCDF congeners. (See TE.)
DOB -- 4,4'-dibromooctafluorobiphenyl.
DQO -- data quality objective.
EMAP -- EPA’ s Environmental Monitoring and Assessment Program.
EMDL -- estimated method detection limit. See MDL.
EPA -- U.S. Environmental Protection Agency.
FDA -- U.S. Food and Drug Administration.
fillet -- a slice of boneless muscle tissue of fish.
formula -- molecular formula of a chemical compound.
GC/ECD -- gas chromatography with electron capture detection.
GC-MS -- gas chromatography - mass spectrometry.
HEPA -- high-efficiency particle air, such as in high-efficiency particle air laminar-flow hood.
high-molecular-weight PAH -- PAHs with >4 rings and molecular weights >202 amu.
HPLC -- high-performance liquid chromatography.
IDL -- instrumental detection limit. Calculated by multiplying the standard deviation of the replicate measurements by 3.143 (EPA 1984b).
lipid -- fats and other esters that are insoluble in water, but are extracted by solvents such as alcohol, ether, and (in this study) methylene chloride.
low-molecular-weight PAH -- PAHs with <3 rings and molecular weights <192 amu.
MDL -- method detection limit. Calculated by multiplying the standard deviation of the replicate measurements by the Student’s t value.
MW -- nominal molecular weight of the compound. Chlorine isotope 35Cl was used in the calculation of molecular weight of chlorinated compounds.
µg/g -- micrograms/gram.
ng/g -- nanograms/gram.
New York Bight -- 39,000-km2 sector of the Middle Atlantic Bight continental shelf between Montauk Point, New York, and Cape May, New Jersey, and approximately 1,280 km wide from the Hudson-Raritan Estuary to the shelf edge.
New York Bight Apex -- the New York Bight Apex is bound by the coasts of New Jersey and Long Island, 73°30’W longitude, and 40°15’N latitude.
NIST -- U.S. Department of Commerce’s National Institute of Standards and Technology.
OCDD -- octachlorodibenzo[p]dioxin.
OCDF -- octachlorodibenzofuran.
PAHs -- polycyclic aromatic hydrocarbons.
PCBs -- polychlorinated biphenyls. A PCB is one of 209 compounds having the formula C12H10-nCln, where n = 1-10, i.e., monochlorobiphenyls through decachlorobiphenyl. The term PCBs is used to refer to the entire class or any subset of one or more such compounds. The entire set of 209 PCBs forms a set of congeners. When PCBs are subdivided by degree of chlorination, the term homolog is used, e.g., the pentachlorobiphenyl homolog. PCBs of a given homolog with different chlorine substitution positions are called isomers, e.g., 2,3,4-trichlorobiphenyl and 3,3',5-trichlorobiphenyl are two of the twelve trichlorobiphenyl isomers (Erickson 1992).
PCDD -- see dioxin.
PCDF -- see dioxin.
pg/g -- picograms/gram.
pg/µL -- picograms/microliter.
physiological condition -- refers to the relationship between a fish’s length and weight. As a fish’s weight increases for a given length (i.e., the fish becomes “plumper”), its physiological condition is considered to be better, or at a higher level. When such length-weight relationships are used as indices of physiological condition, they are called “condition factors.”
ppb -- parts per billion. ng/g.
ppm -- parts per million. µg/g.
pptr -- parts per trillion. pg/g.
QA -- quality assurance.
QC -- quality control.
RPD -- relative percent difference. Calculated by dividing the difference of duplicate values by the duplicate mean, then multiplying by 100.
RSD -- relative standard deviation. Calculated by dividing the standard deviation by the mean value.
BHCs -- sum of ß-BHC, -BHC (lindane), and -BHC.
chlordanes -- sum of chlordane, -chlordane, trans-nonachlor, heptachlor, heptachlor epoxide, and oxychlordane.
SRM -- standard reference material.
TCB -- 1,2,3-trichlorbenzene.
TCDD -- see dioxin.
TCDF -- see dioxin.
TE -- toxic equivalent. A means of summarizing dioxin data, including the less toxic, chlorinated dibenzo[p]dioxin and dibenzofuran congeners together with 2,3,7,8-TCDD (EPA Method 8290, September 1994). The 2,3,7,8-TCDD congener is assigned a TE factor of 1.0.
z-score -- a number calculated to compare concentration values obtained for an SRM with consensus concentration values (IUPAC 1993). Obtained by the difference between the individual result and the consensus result, divided by the consensus standard deviation. An absolute z-score of < 2 is considered satisfactory, 2-3 questionable, and >3 unsatisfactory (Parris 1995).

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(File Modified Nov. 19 2010)