What is analytical chemistry? Analytical chemistry is what analytical chemists do. Analytical chemistry is a measurement science consisting of a set of powerful ideas and methods that are useful in all fields and midicine. Analytical chemistry is a science of measurement and characterization. Analytical chemistry is a science of instrumentation and measurements.

Analytical chemistry is a scientific discipline that develops and applies methods, instruments and strategies to obtain information on the composition and nature of matter in space and time.

Classification of analysis Qualitative Analysis Determination of chemical identity of the species in the sample. Quantitative Analysis Determination of the amount of species or analytes, in numerical terms. Hence, Math is heavily involved. (Excel or Oringin or Matlab) In order to perform quantitative analysis, typically one needs to complete qualitative analysis. One needs to know what it is and then select the means to determine the amount

Quantitative Analysis Gravimetric methods: mass is measured. Volumetric methods : volume is measured or used to determine amount of sample via concentration. Instrumental Methods: use an instrumental technique to assay the amount of sample. Such as electroanalytical, spectroscopic, chromatographic.

The Role of Analytical Chemistry

Spacecraft Science instruments are state-of- the-art tools that will acquire information about the Martian environment. They include: Cameras: Panoramic Camera Microscopic Imager Spectrometers Miniature Thermal Emission Spectrometer(Mini-TES) Mossbauer Spectrometer(MB) Alpha Particle X-Ray Spectrometer(APXS) Grinder Rock Abrasion Tool (RAT) Magnets Magnet Array The instruments use calibration targets, including a sundial, to determine accurate colors, brightnesses, and other information collected by the instruments.

Gene Chips (Microarray) Principle is to analyze gene (mRNA) or protein expression through large scale non-radioactive Northern (RNA) or Southern (DNA) hybridization analysis Brighter the spot, the more DNA Microarrays are like Velcro chips made of DNA fragments attached to a substrate Requires robotic arraying device and fluorescence microarray reader

Gene chips

Microarray Analysis Examples

Labs-on-a-chip

Atoms on Gold Surface Scan Tuning Microscopy (STM) Atom Force Microscopy (AFM) Imagesof proteins

Steps in a Typical Quantitative Analysis 1) Select a method: accuracy, resource and cost (e.g., blood samples, pharmaceutical products. 2) Sampling: obtaining “a representative sample”, especially important for mass products. 3) Sample preparation and handling a) Dissolution or digestion of samples b) Preparation of solid samples 4) Define replicate sample: accuracy, resource and cost 5) Eliminating interferences: blank control 6) Calibration and measurement 7) Calculation and data reduction 8) Evaluating results and estimating their reliability

Please pay attention to the terms Assay, analyze, determine Heterogenous (homogenous) materials Replicate samples or replicates Interference Specific, selective Matrix or sample matrix Calibration

Homework What is the difference between species molarity and analytical molarity? What are the three common way to express percent concentration? What are ppm and ppb? What is p-Functions?