Analytical Chemistry Methods

• Analytical chemistry studies the principles, laws, and techniques for determining the chemical composition of natural or artificial samples.
• Chemical Analysis refers to the operational techniques used to determine chemical composition.

Analytical Chemistry Methods

• Analytical chemistry methods are classified into chemical, instrumental, and separation methods.
• Chemical/Classical Methods: Based on analyte chemical properties and instrumentation is minimal.
• Gravimetry and volumetry are chemical methods and are classified as qualitative and quantitative analysis.
• Qualitative: Identifies elements or chemical groups in a sample.
• Quantitative: Determines the amounts of elements or chemical groups in a sample.
• Instrumental Methods: Based on chemical-physical properties.
• These methods use instruments other than balances and burettes.
• Instruments are classified based on the measured property, such as optical/spectroscopic, electrochemical, separative, or chromatographic.
• Separation Methods: These are used to separate compounds to eliminate interferences and facilitate measurements.

Sample Size

• Ultra-microanalysis: Uses samples up to 0.0001 g
• Micro analysis: Uses samples up to 0.01 g.
• Semi-micro analysis: Uses samples up to 0.1 g.
• Macro analysis: Uses larger samples.

Analyte Concentration

• Trace: Determination for samples with trace amounts of analytes
• Macro and micro components: Determination for samples with macro and micro components in analytes

Analytical Process Methodology

• The analytical process involves problem definition, method selection, optimization, sampling, data acquisition and treatment, and result assessment.

Analytical Result Quality

• Primary objective: Quality depends on accuracy and representativeness.
• Capital properties depend on basic properties.
• Basic properties are sensitivity, selectivity, precision, and sampling.

Errors

• Errors in analytical chemistry are alterations of the provided information, indicating differences between the true/accepted value and individual/averaged results.
• Errors can be attributed to a result or an analytical process.
• Systematic errors: Operational alterations that reference the true/accepted value; affect accuracy.
• Deviation is predetermined, either excess (+) or defect (-) and can be constant or proportional.
• Instrumental/Apparatus Errors: Errors from apparatus and reagents.
• Measuring devices can have systematic errors.
• Pipettes, burettes, and volumetric flasks may deliver slightly different volumes than indicated.
• Method Errors: Originate from chemical and physicochemical properties of the analytical system.
• Personal Errors: Result from an individual's inability to make accurate observations (e.g., color confusion).
• Operative Errors: Physical in nature and associated with analysis manipulations.
• Random Errors: Result from typical experimental fluctuations, from multiple analyte determinations in sample aliquots.
• Characteristics: Equally probable excess (+) or defect (-), smaller deviations are more frequent; normal distribution is represented by infinite measurements.

Laboratory Biosecurity

• Security: Being safe, free, and exempt from harm or danger.
• Bio: Set of all living things.
• Biosecurity: Protection of life through internationally recognized preventative measures. Intended to protect the health and safety of personnel and their environment.
• It applies to healthcare workers, laboratory researchers/technicians, patients, the general population, and the environment.
• Risk: Probability of an individual developing health problems due to exposure to dangerous situations.
• Accidents arise from risk, unsafe behavior, and unsafe conditions.
• Biological: Probability of a material of biological origin emitting biological entities (viruses, bacteria), coming into contact with a receptor, with adverse health consequences or environmental concerns.
• Physical: Factors that depend on the physical properties of objects (physical load, noise, illumination, ionizing and non-ionizing radiation, elevated temperature, vibration).
• Chemical: Probability of a chemical contaminant contacting a receptor, leading to adverse health consequences.

Laboratory Safety Norms

• Activities should only be carried out by qualified personnel, never work alone when performing experimental activities.
• Know safety elements like fire extinguishers, emergency exits, eye washers, spill kits.
• Keep work areas clean and free of books, coats, bags.
• Eating, drinking, smoking, applying makeup are prohibited.
• Food and drugs should not be stored inside the laboratory, especially with other chemicals.
• Wear appropriate clothing, closed shoes, and tie back hair.
• Order and cleanliness are crucial.
• Wash hands after working in the lab and before leaving.
• Only use equipment that you know how to operate.
• Wear gloves to avoid contact with chemical or biological substances.
• Pipetting by mouth is prohibited.
• Running is prohibited.
• Do not inhale, taste, or smell products without proper knowledge.

Substance Classification By Danger

• Explosives: Substances/preparations that can explode under the effect of a flame.
• Oxidizing agents: Substances/preparations that, in contact with other substances, especially flammables, produce a strongly exothermic reaction.
• Extremely flammable: Substances/chemical products with an ignition point below 0°C and a boiling point less than or equal to 35°C.
• Highly flammable: Substances/preparations that, ignite at room temperature
• Flammable: Substances/preparations with an ignition point of 21°C–55°C .
• Very toxic: Substances/preparations that can cause serious, acute or chronic risks, including death, through inhalation, ingestion, or skin penetration.
• Harmful: Substances/preparations that can cause limited severity risks through inhalation, ingestion, or skin penetration.
• Corrosive: Substances/preparations that can have a destructive effect on living tissue upon contact.
• Irritants: Substances/preparations that can cause an inflammatory reaction through immediate, prolonged, or repeated contact with skin or mucous membranes.
• Dangerous for the environment: Substances/preparations that can present immediate or delayed risks to the environment.
• Carcinogens: Substances/preparations that can cause cancer or increase its frequency through inhalation, ingestion or skin penetration.
• Teratogens: Substances/preparations that can cause lesions in the fetus during intrauterine development through inhalation, ingestion, or skin penetration.
• Mutagens: Substances/preparations that can produce alterations in the genetic material of cells through inhalation, ingestion, or skin penetration.

Chemical Substance Risk Labels

• Health Risk Code:
• 0: Common material
• 1: Slightly dangerous
• 2: Dangerous; use respiratory equipment
• 3: Extremely dangerous; wear full protective clothing
• 4: Too dangerous to breathe vapor or liquid
• Reactivity Risk Code:
• 0: Stable
• 1: Unstable when heated; take normal precautions
• 2: Possible violent chemical change; use hoses from a distance
• 3: May detonate with strong shock or heat; use monitors
• 4: May detonate; evacuate area if materials are exposed to fire
• Flammability Risk Code:
• 0: Materials that do not burn
• 1: Need to be preheated to burn
• 2: Ignites when moderately heated
• 3: Ignites at normal temperatures
• 4: Extremely flammable

Lab Safety Equipment

• Individual Protection Equipment: Goggles, gloves, lab coat, closed-toe shoes, face masks, and hearing protection.
• Common Lab Materials and Procedures:
  • Beakers (Berlin): Used for heating liquids and preparing solutions, not volumetric.
• Erlenmeyer Flasks: Conical flasks with a wide base and narrow neck, used for boiling liquids and preparing solutions volumetrically.
• Funnels: Used for transferring liquids during the separation process, called filtration.
• Volumetric Flasks: Pear-shaped container with a flat bottom and a long, narrow neck, used for volumetric measurements.
• Graduated Cylinders: Cylindrical containers used for volumetric measurements.
• Volumetric Pipettes: Cylindrical glass tubes, wide in the middle and narrow at the ends, that may have one or more calibration marks (aforos) for delivering a specific volume of liquid volumetrically.
• Graduated Pipettes: Cylindrical tubes, graduated, open at the ends, used for volumetric measurements.
• Pro-pipettes: Spherical rubber bulbs used to load and unload pipettes.
• Burettes: Long, graduated tubes with a tap or stopcock at the bottom to regulate liquid flow, attached to a clamp or universal support volumetrically.
• Test Tubes: Glass or plastic tubes with one open end, held with a clamp or rack.
• Flasks: Glass flasks with a long neck and round body, used for heating liquids.
• Distillation Flasks: Similar to flasks but with a side tube on the neck, used for distillation.
• Test Tube Racks: Wood, metal, or plastic stands.
• Stoppers: Cork or rubber.
• Condensers/Refrigerant Tubes: Long tubes surrounded by another concentric tube of larger diameter.
• Wash Bottles/Squirt Bottles.
• Thiele Apparatus: Detects the melting point.
• Decantation/Separation Ampoules: Pear-shaped containers that separate immiscible liquids.
• Iron/Universal Support: Stable base that holds clamps or rings for support.
• Crystallizers: Cylindrical containers used for evaporating liquid from a solution.
• Watch Glasses: Concave circular glasses.
• Tripod: Used to support metal meshes that hold materials being heated.
• Metal mesh: Asbestos center.
• Bunsen burners.
• Test Tube Brush: Used to clean glassware.
• Forceps and Tongs.
• Metal Spatula.
• Thermometer.
• Mortar and Pestle.
• Analytical Balance.

Laboratory Procedures

• Solutions: Homogenous mixture of a solid, liquid, or gas with another liquid, it has 2 components: solvent and solute.

• Solvent: Original substance.

  • Resultant liquid: Solution or Dissolution.

• Solutions can be CHEMICAL or PHYSICAL depending on whether reaction has occurred.

• Can be prepared using test tubes, flasks, or beakers for liquids.

• Solids need to be pulverized: Use a mortar to reduce size.

• Gases are mixed using Woolf flasks.

• Drying: Operation to separate a liquid from a solid using non mechanical procedures.

  • Solids: Place them on absorbent sheets to remove solvent traces.
  • Organic Substances can be dried in a vacuum at room temperature.
  • Liquids are dried by treatment with dehydrating agents.
  • Gases are dried by passing through desiccants or bubbling through concentrated sulfuric acid.

• Precipitation: Solid obtained from a solution, can be performed via chemical reaction, solvent evaporation, or rapid cooling.

• Filtration: Separation of solid particles from a liquid.

• Gravity Filtration: Relies on gravity.

• Vacuum Filtration: Applies atmospheric pressure to the system.

• Decantation: Separation of a heterogeneously mixed solid from a liquid or two immiscible liquids with different densities.

• Calcination takes place with heating and has 3 objectives: eliminate water, carbon dioxide, and oxidize substances.

• Weighing Samples: Analytical balances are designed to determine the mass of a body.

  • Accuracy implies minimal error and sensitivity works with reduced measurements.

• Sampling: Extracting a number of individuals from a population.

  • Simple Random or Unrestricted: Items have an equal and independent opportunity to be included.
  • Restricted – Stratified: Population is divisible into homogeneous groups/classes (strata), afterwards sampling of each group uses simpler random methods; the resulting sample is a stratified sample.

• Volume Measurements: Precision is how similar results are and Exactitude is how close a measurement is to the actual accepted value.

• Volumetric material accurately has specific graduations. Material includes pipettes, flasks, burettes, etc.

• Non volumetric materials have estimations and include tube test tubes, funnels, beakers, etc.

• Volumen makes reference to all occupied space, capacity is the maximun volume that can be stored within.

• Liquid Meniscus: Describes liquid surfaces, they are either convex or concave.

  • Concave Meniscus forms from high molecule attraction to the glass than to each other
  • Convex Meniscus forms if molecule attraction is greater than the glass's.

• Calibration Methods: Instrumental methods used to relate measured signs to concentration

  • Direct Calibration: Using external signals
  • Added Calibration: Adding standard
  • Internal signals.

Volumetric Analysis

• Volumetry is the part of analytical chemistry that studies phenomenon involved in titration. Measured unknown substance gets determined by known standard solution
• Determination takes place by adding standard solution to unknown solution and measuring concentration.
• Volumetric methods determine amount of analyte via standard volume that is used to react completely.
• Indicator is a substance that can chemicaly shift according to the substance's medium and change it´s capacity to absorb light, color. It doesn't participate in the main reaciton, instead it changes structure.
• Titrant/ Volumetric reference is quantity used to determine substrate in a titration, has a known concentration.
• Acid-Base volumetry analyzes acidic solutions. Volumetric Acid-Base is for neutralizing acid and base, from different concentrations.
• Neutralization is widely used for acid-base reactions
• Volumetry refers to the volume of solution used to determine the concentration of an element.
• Acid/Base Volumetric Types:
  • Alkalimetrics determine the concentration of the base by using strong acids.
  • Acidimetrics determine the concentration of the acid by using a strong base.
  • Also can use redox, precipitation, for complex formation.

Gravimetric Analysis

• Gravimetric analysis uses techniques that measure mass of product to determine mass of an analyte in a sample, can be used in quantitative analysis of a lab.
• Gravimetric Methods fall under classification.
  • Precipitation is insoluble analyte interest method.
  • Volatilization separates by boiling or distilling
  • Electrogravimetrics provoke chemical reactions by passing electrical current.
  • Extraction determines percentage of an alloy component
• Gravimetric: is exact and precise and doesn't require test liquids
• Slow, personal, and training is necessary.
  • Gravimetric Processes have 5 steps: Precipitation, digestion, purification, filtration, and drying.

Separative Techniques

• Distillation heats a components into to either its fluid, gas, or both states via condensation. Is effective for separating volatile and not volatile materials
• Vapor pressures pressure liquids apply escaping vapor over the fluids surface, establishing equilibrium.
• Boiling points occur when Vapor Pressure reaches External Pressure; normal points reach 760 mmHg/1 atm.
• Distillation Methods:
• Simple: Liquid mix distilled if there is only one form or if a substance contains multiple volumes.
  • Atmospheric Pressure: Occurs at set environment
  • Subatmospheric Pressure: Reduces tension and boiling point of the subject matter.
• Fractionated: For substances of different boiling volumes and temperature ranges
• Vapor: Isolates and enhances high points while also reducing temperatures.
• Solvents are used to separate by transferring solute and soluble properties. Is used by inmmiscible solvents being in contact.
• Extractions with solvents are ways to separate dissolved substances with immiscible solvents and differences
  • Solvent Extractions define isolating a component and its sources, in organic or aqueous environments
• Solvents use a rapid kinetic to transfer mass between phases. Ideal solvent is an organic product to extract organics and should be relatively un reactive.
• Extraction:
• Discontinuous/Batch mixes and separates in only one step and may only require an apparatus
• Continuous requires batches to quantitatively remove something from a desired product
• Countercurrent separates values between differing conditions, requires special and complex mixture of phases.

Instrumental Analysis

• Modern separation and quantification methods rely on physical and chemical phenomenon.
• Spectroscopy interacts between radiation and matter, using atomic and molecular techniques.
• Spectrometry and its derivations quantify radiation strength via photoelectric detectors.
• Spectrometric methods relate to electromagnetic radiation that take variable forms from heat or light, they are hard to recognize but can include rays.

General radiation properties

• Classical sinusoidal models define waves and electromagnetic radiation does not require a media
• Light has wave and particle natures:
  • Waves oscillate using perpendicular fields
  • Particles use photons.

Spectro chemistry

• Every molecule has light to absorb depending on chemical structures
• Absorptions are dependent on the amount of light and transmittance via spectrochemical measurement.
• Spectroquimics have for categories for radion power (P), that calculates energy per unit per section.
• Radiowave strength gets determined by radiation detector.
• Low absorption occurs when a molecule increases energy after light gets absorbed
  • Emission diminuishes energy and fundamental light is at minimal strength. Law states with absorptions needs 1/2 powers and radiation must pass through to analyse.
  • Transmittance defines ratio of light through a medium (T/p)
  • Absorbance (A) is intensity of absorbed light.
• Absorbance and transmission diminish with the increased strength. If strength doesn't get absorbed and therefore equals cero.

Physical Laws/Theorems

• Lambert: Monochromatic light diminishes to medium
• Beer: Light absorption and concentration are directly proportional.
• Lambert-Beers: Light's proportion is proportional to the concentration and thickness of a given product.
• The characteristics and nature of the product must be considered to understand light absorbance.
• Spectroscopy is used as a popular analytical method, like spectrophotometric.
  • Is able to work through, organic and inorganic. Has variable sensitivity and accuracy.
• Colorimetry and Spectrophotometry: Are both analyical procedures which the concentration of a substance is analyzed.
• Colorimetrics use absorption of radiation and coloured tests can take place with Beer´s Law.
• To analyze, the light intensity must directly coordinate with analysis
• Spectrophotometer components (light instrument measure), light source (selector/detector): Light goes through the monochrometer and wave lengths of the rays get selected, they cross the optical pathway and measure strength.
  • Instruments can manage electro magnetic radiation and identify energy. Dependancy comes down on design and selection. Breakdown by separation into quantifiable and qualitive bands.

1. Radiant energy
2. Wave selectors for measurement
3. Placeable sampling compartment
4. Strength Detector/Sensor
5. Readings/systems

• Usage
• Adjust before heating 10 minutes to signal red light adjustment and select appropriate wavelength. Close the port. Inserts with light with sample and cover them. Adjust transmission and re-open, lower cover while sampling.

Precautions

• No bubbles exist. Measure volume to prevent overflows. Clean equipment and maximums up to 3/2 . Liquids may damage equipment.
• Spectrocolorimetrics shouldn't be used with equipment. To prevent over heating the equipment should be switched off if no loner needed.
• Molecular Lights absorb waves from molecules at wave lengths that can be analyzed. Substances are selected based on range for equipment and the scanning occurs at the required wavelenght for light absorption,
• Colorometric calibration requires samples and tests. Rationale: If a known substance is recorded with absorbance, values can calculated.

Absorption Spectrometry

• Atomic Absorption helps define atom concentration and requires energy absorption of atoms and UV visual specturm of gazeous atoms or metallics.
• Key components: Light sources, graphite furnace, collimators, detectors.
• Flame Photometry: Can determine composition of elements by emitted radiation, varies depending on flame composition.
• Sampling can happen at a low level, and radiation is then produced when elements get excited. Only works with alkali and alkali-earth because the require an electron. Lamps provide energy.

Chromatography

• Chromatography group separates and analyses component and helps define substances in complex mixtures. Each use a form to analyze, detect, and quantify each component with two phases. They include a force or state by mobile phase (Mp) and fixed solid state is a Stationary one (S). They are both used in conjunction with the components of matter and that determines how and when they get distributed.
• Elements in a system will often advance through mobile phase: Those with retention move with the mobile flow and weakly connected parts will be in motion. Each component separates in groups or zones for quantitative and qualitive analysis.
• The main component is analytes
• MP is the one with defined phases and may include supercritical components and injected with analyte dissolvents.
• SP is a solid with a porous structure inside the colum.
• Cromatograms show the optimized separation and the number of groups is also proportional to the mix. It's equipped for many areas.
• Cromatography shows a method that uses two different and fixed points. Key attributes and conditions determine.
• Mobile liquid moves through the column. Samples get tested, and pure elements separate and dissolve easily.
• Classififications:
• Physical forms/ state, responsible contact type that determine how to categorize or separate.

Flat: phase on plain platae (paper or small cap): Column: Phase can use a column to categorize and identify:

• Liquid: Gas with supercritical fluids. Paper in a downward configuration for solvent systems with a static crystallized phase. It has solvent that distributes on the paper. SP must have a polarized charge. Paper is where the sample is placed. This helps with the stability. The samples are used to classify depending on their affinity on the solvent system, and determines whether the stain will run in a fluid or polar configuration

Chromatography in Thin Layers

• Solid to liquid to determine ascendecy. Solvents, solids, or liquids that adhere liquids and solvents. A spot is applied and separation produces a capilary.
• Column C. ( HPLC) helps identify and separate with solvent with absorbent and acts differently with the solid. Rate varies depending on column (acetonile) with liquid. Analyzes in the colum. The method is popular in criminal analysis.
• Gas C. (GC) Helps seperate and is applied by a gas, for analyzing continues gas flow. The sample takes part with the gas phase and flows through the temperature controlled zone to determine composition after separating. The method enables easy operation, velocity, compound observation and analysis. GC (fast), HPCL (slow)

Quimica Inmunologia

• Imunological Term applies to living organisms that form antibodies. They are able to know what is strange with HLA. Also helps detect bacteria.

Ag (Antigens)

• All proteic substances are introduced.
• Ac (anti bodies,) reacts to an antigen. During a defence mechanism in leucocitos, it helps digest invaders by fagocitosis.

Microscopy

• Microscopy makes objects from the study. The methods and the tools are not very visible to the average. Each requires a method. In a Microscopy optical system are shown dark and areas are highly lit. Has the capacity to use differing Lens Systems.
• Simple: Lupa uses 1 Lens.
• Composite 2 or more Lens.
• FootBase for Support
• Column.
• Canon- Tube for cylindrical shape.
• Revolver to place Lens.
• Plata.
• Clamps.
• Mobile cart to move.
• Screws.
• Lenses.
• Wave Definer.
• Diafragmas
• Ocular Lens.
• Resoluction: Separate images by small distance.
• Definition form a clear definition.
• MEB can analyze high resolution samples with great and wide range.

1. Residues
2. Fiber textiles
3. Paints and glass
4. Weapons.

• Analysis and biological testing for cell tissues and cellular structures. All can be done using energy with dispersing tools with dispersing tools/eds for forensics.