Nanalytical Chemistry Essay examples

Submitted By Gvlrule1
Words: 635
Pages: 3

* Qualitative Analysis- what is in an uknown * Quantitative Analysis- How much is present * Analyte- substances being measured * Species- any chemical fo interest * Analytical chemistry is used everywhere * Steps in Chemcal Analysis 1. Formulatig a question 2. Selecting the analytical procedure (search literature) 3. Sampling- select a representative sample i. Replicate samples 1. homogenous Vs. Heterogeous 2. random heterogenous Vs. segregated Heterogenous a. random heterogenous= differences in concentration occur randomly and I a fine scale b. segregated heterogenous- large regions have obvious different compositions. Must make a composite smaple. (pull out same number as %) ii. Quantitative transfer- complete transfer 4. Smaple preperatio- trnasformig a sample into a state sutiable for analysis 5. Analysis iii. Calibration and calculation fo results, replicate measurements, compare analytical methods iv. Uncertainty/error 6. Interpretation and reporting 7. Drawing conclusios * Types of Analysis * Gravimetric = measure mass of analyte or related compound * Volumetric = measure volume of solution containing sufficient reagent to react completely with the analyte * Electroanalytical = measure electrical properties such as potential, current, resistance and quantity of electricity * Spectroscopic = measurement based on interaction of electromagnetic radiation and analyte * Mass Spectrometry = measure of mass to charge ratio (m/z) of analyte * Others: e.g. radioactive decay, heat of reaction, optical activity, refractive index, rate of reaction * Calibration curves/standard curve= graph of detector response as a function of analyte concentration * Replicate samples= measure amples in separate aliquots/vials to account for variability * Interference- species other than analyte increase/decreases analytical method. Makes it seem there is more analyte sample * Masking- transformation of an interfering species into a form that is not detected * Chapter 1 * Fundamental units * Meter, kilogram, second, kelvi, mole, ampere, candela * Derived units * Hertz,newton, pascal, joule,watt,coulomb,volt,ohm,farad,Becquerel *
Metric Prefix Table Prefix | * Symbol | Multiplier | Exponential | yotta | Y | 1,000,000,000,000,000,000,000,000 | 1024 | zetta | Z | 1,000,000,000,000,000,000,000 | 1021 | exa | E | 1,000,000,000,000,000,000 | 1018 | peta | P | 1,000,000,000,000,000 | 1015 | tera | T | 1,000,000,000,000 | 1012 | giga | G | 1,000,000,000 | 109 | mega | M | 1,000,000 | 106 | kilo | k | 1,000 | 103 | hecto | h | 100 | 102 | deca | da | 10 | 101 | | 1 | 100 | deci | d | 0.1 | 10¯1 | centi | c | 0.01 | 10¯2 | milli