Term
What are the main sources of anthropogenic contaminants? |
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Definition
Agriculture, industry and households |
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Term
Natural Contaminant sources |
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Definition
Animals, Plants, Minerals |
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Term
By-products of imcomplete burning in boilers |
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Definition
Fly ash, bottom ash, boiler slag |
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Term
Five main conditions for formation of photochemical smog |
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Definition
Heavy traffic, sunlight, high temp, ozone, quiet weather |
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Term
Natural sources of aerosols |
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Definition
Deserts, oceans, forests, fires, volcanoes |
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Term
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Definition
Chemical species which affects the outcome of a measurement. |
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Term
How do you eliminate interferences? |
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Definition
Separating analyte from sample matrix. Part of sample pretreatment step. |
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Term
Seven steps of quantitative analysis |
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Definition
Method selection, Sampling, Solution Preparation, sample pretreatment, analytical measurement, calculating result, statistical evaluation |
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Term
When is a sample representative of the bulk of a material? |
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Definition
If its composition is identical to the average composition of the bulk material |
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Term
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Definition
Collection of a gross sample Reduction of gross sample to homogeneous laboratory sample |
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Term
Three methods for calculating the analytical result |
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Definition
Calibration curve method, internal standards method, standard addition method |
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Term
What is the calibration equation? |
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Definition
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Term
Describe the standard addition method. |
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Definition
Known amounts of analyte are added to the sample with unknown analyte conc. The analytical signal is measured before starting the additions, and after each addition. |
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Term
Equation for multipoint standard addition of varying volumes |
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Definition
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Term
When should varying volume multipoint addition be used? |
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Definition
When there could be changes to the sample matrix |
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Term
Equation for determining concentrating using multipoint constant volume |
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Definition
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Term
When is the internal standards method used? |
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Definition
Instrument response varies slightly in time; Sample loss can occur during pretreatment |
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Term
Equation for the internal standards method |
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Definition
C = [(1/F)*(C(internal)/Z(internal)] * Z(analyte) |
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Term
What are the three main types of experimental error? |
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Definition
Systematic, random, gross |
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Term
How do you correct instrumental errors? |
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Definition
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Term
What is a gross error, and how do we determine a gross error? |
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Definition
Large outlier. Identified using statistical evaluation. |
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Term
Can we identify and quantify the source of random error? |
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Definition
No, as the error introduced is usually very small. |
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Term
How do we characterize precision and accuracy? |
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Definition
Precision - variance, standard deviation, RSD Accuracy - Absolute or relative error |
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Term
What are the two main types of columns used in chromatography? |
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Definition
Packed columns and open tubular columns |
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Term
Three types of GC detectors |
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Definition
Flame-ionisation (hydrocarbons), Thermal conductivity, Electron capture detector (halogens) |
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Term
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Definition
Gas tank - Pressure regulator - Sample port - Oven - Detector |
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Term
What are the requirements of the partition coefficient such that there is separation and preconcentration of the analyte? |
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Definition
K >> 1 ; [Sample] >> [Extractant] |
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Term
What is column resolution? |
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Definition
Quantitative measure of its ability to separate 2 analytes. R = 2[(tb - ta)/(Wa + Wb)] |
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Term
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Definition
The difference between the titrant volume to equivalence, and the actual titrant volume used.
Error = V(equiv.) - V(end) |
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Term
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Definition
Light source - Premix Burner (Sample, fuel, air) - Monochromator - Detector |
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Term
What are releasing agents and protective agents? |
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Definition
Releasing agents react preferentially. Protective agents form stable, non-volatile compound with the analyte. |
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Term
Why is the analysis of phosphoric compounds important? |
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Definition
Orthophosphate supports eutrophication, which leads to anoxic conditions. |
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Term
What are the main sources of ammonium salts as water comtaminants? |
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Definition
Decomposition of proteins, Atmospheric nitrogen, agriculture, cleaning products |
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Term
What are the main sources of anions as water comtaminants? |
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Definition
Erosion, sedimentary release, agriculture, soaps, sewage treatment |
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Term
What are the main organic derivatives as water comtaminants? |
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Definition
Organic decay, algae, oils, pesticides, detergents |
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Term
List aerosol control devices in order of increasing particulate size. |
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Definition
Electrostatic precipitators, Fabric filter separator, Scrubber, Cyclone, Settling chamber |
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Term
What are the effects of water hardness? |
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Definition
Interfering with cleaning tasks, Formation of mineral deposits in pipes, Flocculation of colloidal particles in soil. |
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Term
What are the parameters of water hardness? |
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Definition
< 60 mg/L - soft >270 mg/L - hard |
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Term
Formula for the student t-test |
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Definition
mean - true > ts/sqrt(n) : no difference |
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Term
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Definition
F =variance 1/variance 2 : compared with critical f value |
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