Basic Lab Practices

7/28/2019 Basic Lab Practices

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Overview

Lab Safety SOPs

Lab Techniques

Continuous Improvement

Resources and References


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Lab Safety

Review MSDS

Physical and Chemical Hazards Control Measures

Reactivity

First Aid Measures

Disposal


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Lab Safety6

EPA Chemical Compatibility Table


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Lab Safety

Housekeeping #1 safety problem within university labs12

Benefits of clean and orderly lab and manufacturing

environments

Decrease the likelihood of product/sample contamination

Minimize chances of long term health effects by minimizingpersonnel exposure

Decreases the probability of safety mishaps Contamination of energetic materials can result in increased sensitivity or ignition of the EM.

Accident investigations in explosives facilities frequently identify dust buildups as the initiation

source propagation path.1

Increases efficiency Unless safety has been demonstrated for the EM at hand,

cleaning agents containing basic alkali or alkaline earth metal

salts should not be used where nitrated organic explosives

may be present. More sensitive explosive compounds may

form1.


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Lab Safety


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Lab Safety

Spills Minimize the likelihood4

Maintain a neat and organized work area

Keep containers sealed when not in use

Use plastic or plastic coated containers

Secondary containment for storage and transport

Response Alert others in and around the work area

If the material is volatile, turn on nearby ventilation.

If there is possibility of an acute respiratory hazard, evacuate. You should already be familiar with the MSDSs for the chemicals you are working

with. If not, investigate the hazards before cleaning up or ask for help.

- Ensure that incompatible materials are not used to clean or contain the spill

Commercial spill kits are available, some of which are packaged in a container thatcan be used to lab pack the spill cleanup waste. They generally include absorbentmaterials to prevent the spread of and absorb the spill, as well as bags

Energetic material spills

- Notify supervisor- Take precautions to avoid initiation while cleaning avoid friction, heat, ESD,

impact and incompatible materials

Mercury spills

- Clean-up kits for mercury spills


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Lab Safety

Chemical Management All materials should be labeled

ID label must contain the Name, PN, Rev., LN, quantity and unit

Labels on items containing explosives must state the NEWt

NFPA label for hazardous materials/chemicals

Other useful information Concentration of prepared solutions

Date opened for materials that do not have an indefinite shelf life

Special storage requirements if any

Expiration Date

- Could be N/A for some items, such as silicon dioxide

- Always follow manufacturers label expiration date

Materials and supplies should have a defined and identifiedlocation, and should be kept there when not in use Organization must ensure chemicals that are incompatible are not

stored together

Inventory should be tracked so that waste quantities, materialage, and supply are known


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Lab Safety

Hazard Controls

Hazard Types Chemical Respiratory

Skin

Physical

Noise Explosion

Fire

Mechanical

Electrical

Ways to Control Hazard Exposure Eliminating hazard Engineering controls

PPE

Scale


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Lab Safety Design considerations for facilities10

Lab air No recirculation

Negative pressure relative to surrounding areas

Locate hoods away from doors, air vents, operable windows and traffic areas

- Incompatible materials should use separate extraction systems

- Exhaust stack height should be sufficient to prevent exhaust recirculation back into building - 10 ft works for most

applications

Fire safety More than one unobstructed egress

Flammables stored in appropriate cabinet

Desirable material properties for work surfaces/tools Non-sparking

Non-absorbent

Easily cleaned

Conductive

Chemically resistant

Safety showers and eyewashes 29CFR1910.151(c) states Where the eyes or body of any person may be exposed to injurious corrosive

materials, suitable facilities for quick drenching or flushing of the eyes and body shall be provided within the

work area for immediate emergency use.2

ANSI Z358.1 gives numerous requirements, including that the units should be activated weekly to ensure

correct operation and that they be located at a distance that takes no more than 10 seconds to reach.3

Portable units are good supplements but are not acceptable in lieu of stationary units 10


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Lab Safety

Intrinsically Safe Electrical Circuits

Class I (multiple groups)- for vapors existing between the lower andupper explosive limits

Class II (multiple groups)- for airborne dusts above the lower

explosive limit

Class III - for fibers usually associated with the textile industry

Class II G is often the class and group satisfying the conditions ofworking with explosives

Operational Shields Designed to protect workers from MCI detonation pressure, heat

and fragmentation whenever there is potential for an event.

Tested by simulating the MCI, taking into account workspacetooling and location

Post MCI design criteria for each shield


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Lab Safety

AE Heat Conditioning Device Requirements for

Laboratories1

Must have dual independent heat controllers

Must contain a mechanism for relieving overpressure

Must be vented

If heating elements are used, the design must be such that there is no

possibility of the AE coming into contact with the elements Fan blades must be non-sparking and the fan motor external to the oven

The inside of the oven shall be constructed so that it is easily cleaned

All metal parts not carrying electrical current shall be interconnected and

electrically grounded

Should be installed to give personnel protection from possible energetic

events.

- Quantity, location, and shielding

Separate ovens containing AE by the appropriate QD or use protective

measures to prevent propagation from one oven to the next. Do not place

AE in the same room as the oven unless it has been determined that an

event within the oven will not involve the materials outside of the oven.


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Standard Operating Procedures1

Purpose

Provide process consistency

Processing of EM should be performed remotely when possible Components

Safety Precautions1

MSDS

PPE

Emergency procedures Removal of unneeded explosives from the work area

References to other applicable documents1

Equipment, tools and supplies permitted for use1

Instructions for spill cleanup1

Instructions for scrap AE disposal1

Sample Preparation

Quality Control

Defined Limits and tolerances

Indicators for identifying abnormal conditions1

Troubleshooting

Cleaning1

Record Keeping


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Lab Techniques

Cleaning Solns for Volumetric Glassware e.g. pipettes, burets, vol flasks,

beakers, grad cylinders4

Solution Procedure

Warm 2% detergent solution Fill and use a brush if needed. Rinse with distilled/DI water

Hot dilute alkaline EDTA solution ~ 0.004M with pH =12. Soak for < 15min to avoid etching.

Rinse with weak acid followed by distilled/di water

Chromic acid cleaning solution Soak overnight at room temp or heat to 60C. Reuse until green.

Thoroughly rinse with water and then DI water to remove

chromium ions, which can interfere in EDTA titrations or

spectroscopic work

3-6M HCl or HNO35 Glass adsorbs trace chemicals, especially cations. Soak new

glassware or glassware used for critical work for >1hr. Rinse

with DI water, and then soak in DI water.

Solvent For many organics, a simple solvent rinse followed by the

detergent solution method works well

Cleaning Glassware

Many different approaches, depending on the use of the glassware and the contaminants to be removed


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Pipette Volume Ranges, mL

0

10

20

30

40

50

60

70

80

90

100

Microliter Syringe(Accuracy 1%)

Micropipette (Accuracy0.3-4.5%)

MIN

1 L

MAX

500L

MAX

1 mL

0

10

20

30

40

50

60

70

80

90

100

Vol Transfer Pipette(Accuracy 0.08-1.2%)

Bottletop Dispensers(Accuracy 0.5-1.0%)

MAX

100 mL

MAX

100 mL

MIN

500 L MIN

50 L

MIN

1 L


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Lab Techniques

Volumetric Transfer Pipettes5

Rinse the pipette with working solution before use

Use a rubber bulb to pull the liquid beyond the calibration mark

Replace the bulb with your index finger while gently holding the pipette

tip against the bottom of the vessel

Wipe the excess liquid from the side of the pipette

Touch the tip of the pipette to the wall of a beaker and drain the liquid

until the meniscus bottom reaches the center of the calibration mark

Drain the contents into the receiving vessel while holding the pipette tip

against the vessel wall

When the liquid stops draining hold the pipette against the wall for a few

more seconds before removing the pipette from the vessel

Do not blow out the residual liquid from the pipette

Rinse or soak the pipette after use. Removing deposits from the pipette

after the liquid has been allowed to dry can be difficult.
http://www.youtube.com/watch?v=qorl6rKLmRs


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Lab Technique

Micropipettes5

Set the desired volume if the pipette is adjustable

Wet the pipette tip for more reproducible volumes

Depress the plunger to the first stop, hold the pipette vertically and

place it into the liquid 3-5mm deep. The depth and angle of the tip will

affect the actual volume withdrawn.

Slowly release the plunger

Leave the tip in the liquid for a few seconds

Withdraw the tip without touching the sides of the vessel

Touch the tip to the receiver wall and press the plunger to the first stop

Wait a few seconds and then further depress the plunger to deliver theremaining liquid into the receiver

As micropipettes wear, the accuracy and precision can decrease by an

order of magnitude


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Lab Techniques

Electromagnetic Load Cell

Advantages -High accuracy -Simple structure

Disadvantages -Complex structure -Limited accuracy

Applications -Ultra-precision balances

such as analytical balances

-Small, cheap balances that

require only moderate

accuracy

-Large balances

Electronic Balances7


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Lab Techniques

Electromagnetic Type5


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Lab Techniques

Load Cell Type7


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Lab Techniques

Types and sources of error5,8,9

Air drafts T between sample and room/balance

Change of pressure due to swinging doors, ventilation, movement

Balance levelness

Object proximity to pan center

Moisture

T between the time of calibration and time of use Ex: A T=5C can cause 1mg error in measuring a 100g mass

Buoyancy Objects less dense than the standard mass appear lighter than the actual mass

Ex: 100.00 g of H2O weighed at 1bar and 25C has a true mass of 100.10g

Location (gravity) Adjust balance sensitivity

Static electricity Decrease by using ionizer or increasing humidity

Magnetism

Vibration

Using calibration weights that have been damaged or handled with bare hands


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Lab Techniques Errors in instrument response:

Balance sensitivity can be adjusted by the user - internal or external calibration Linearity error cannot be corrected by the user and should be defined by manufacturer

Weighing by difference is best practice.


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Lab Techniques

Calibration of Analytical Instrumentation

Calibration Standards High purity

Known concentration given by vendor or determined with a primary

standard Primary standards are >99.9% purity and should be stable in storage and under moderate heat so that it can

be dried

Calibration curves5

Determine the response of an analytical method to known quantities

of analyte

General Procedure for Curve Construction Prepare known samples of analyte whose concentrations bracket the expected sample concentrations. Use

at least six calibration concentrations and include a blank.

Measure the responses of the analytical procedure to the standards and record the data. Obtaining triplicatedata points for each concentration allows for more reliable rejection of outliers and a measure of method

precision.

Subtract the average blank response from each individual response, resulting in a corrected response.

Graph the corrected responses versus the known concentrations of analyte by fitting the data to a linear or

quadratic curve using a method of least squares.

When an unknown is analyzed, run a blank with the unknown and subtract its response from the unknown

response before using the calibration curve to determine the analyte concentration.


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Lab Techniques

Analyte concentration at Detection Limit for a linear fit5

3s/m s determined from response range within 5 DL

Response level that gives 99% chance that the analyte is actually

detected

Lower Limit of Quantitation The point at which the quantitative capability is

considered acceptable5:

One way is 10s/m

Another way is that replicate measurements will be within 20%

in accuracy and the CV < 20%

- CV = s/xbar * 100

Limit of Linearity

Sensitivity11 = m/s


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Lab Techniques

5DL


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Other Calibration Methods5

Standard Addition - used to account for matrix effects


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Other Calibration Methods5

Internal Standard Good for analyses where the sample quantity analyzed or the

instrument response varies with time.

Add a known amount of a substance that is not present in

the unknown into standards, samples, and blanks

Construct a calibration curve by plotting analyte signal /

internal standard signal vs. concentration of analyte.

Minimizes the impact of random errors on the determination

results, e.g. instrument fluctuations in flow rate

May reduce systematic errors, such as sample prep losses,

depending on the chemical nature of the internal standard

relative to the analyte

AX/[X] = F (AS/[S])


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Continuous improvement

First, understand the process and the history

Incremental and ongoing

Identify and improve inefficiencies

Developing skill sets Identify and correct safety concerns

Correcting/updating procedures


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Risk Assessment

Aids in determining if action should be taken to mitigate agiven risk

Risk = Consequence Severity X Probability

Insignificant Catastrophic

NearCertainty

ExtremelyImprobable

C ti i t


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Continuous improvement Process Mapping defines a process, how steps are related, communicates the problem to

others, and allows recognition of ways to eliminate waste

yes

no

yes

no

yes

no

yes

yes

no

no

yes

yes

no

no

yes no

Eliminate

yes

no

End Goal


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If the process so inefficient that it is difficult to determine where

to make improvements, start from scratch and draw up the idealstate.

Determine if the ideal state is obtainable or the state that is

closest to the ideal state and feasible.



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Fishbone/Cause and Effect Diagram

Useful for identifying possible causes for a given defect or event

Focuses on determining the root causes before taking corrective action, increasing

the chances for the proper solutions to the problem

Defect

Machines Materials Measurements

Mother NatureManMethods

Poor PM

Antiquated

Humidity

Unknown Quality

No defined shelf life

No QC testing

Poor reproducibility

Inadequate training

No environmental control

Call for wrong materials

Spec outdated

Too open to interpretation

Experience

Absent

Training


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Several representatives closely connected to the

process should participate - perspectives

All ideas should be documented

What controls are there on the factors?

Has this problem occurred before?

Which factors interact with other factors?

Should improvement effort be spent on one factor or

distributed among several factors?



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Lab Safety

Recurring Internal Audit Use a standard template Inspect

Lab signage

Safety equipment, e.g. hoods and safety showers

That appropriate PPE is in use

Housekeeping and organization Chemical safety and proper storage

Electrical safety

Basic fire safety

Lab waste disposal

Be thorough - ask questions Discuss discrepancies with manager

Generate report

Follow up


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Understanding and protecting against hazards Basic understanding of balances, pipettes,

calibration, and calculations

Importance of organization and cleanliness in

efficiency and quality Appreciation for the importance of adhering to

concise SOPs

Cumulative effect of continuous improvement

Important Concepts

OverallImprovement

Time


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Resource Links Safety

Emergency Response Guidebook 2012

Glove Selection Guidance Shower and Eyewash Requirements

OSHA PPE Informational Booklet

Free Chemical Reactivity Software

OSHA Lockout/Tagout

Spill Clean-Up

Non-sparking Tools Static Generated by Flowing Liquids

Metal Activity Series to Help Predict Potentially Hazardous Rxns

AE Requirements DoD Contractors Safety Manual for Ammunition and Explosives

UN Explosive Hazard Classification System and Codes

ATF Explosives Storage Requirements OSHA Explosives and Blasting Agents

Lab Technique/Procedures Organic Lab Technique

Organic Lab Technique II
http://phmsa.dot.gov/staticfiles/PHMSA/DownloadableFiles/Files/Hazmat/ERG2012.pdfhttp://phmsa.dot.gov/staticfiles/PHMSA/DownloadableFiles/Files/Hazmat/ERG2012.pdfhttp://www3.imperial.ac.uk/OCCHEALTH/guidanceandadvice/gloveinformationandguidance/gloveselectionguidancehttp://www3.imperial.ac.uk/OCCHEALTH/guidanceandadvice/gloveinformationandguidance/gloveselectionguidancehttp://www.grainger.com/Grainger/static/emergency-shower-eye-wash-station-requirements-120.htmlhttp://www.grainger.com/Grainger/static/emergency-shower-eye-wash-station-requirements-120.htmlhttp://www.osha.gov/Publications/osha3151.pdfhttp://www.osha.gov/Publications/osha3151.pdfhttp://response.restoration.noaa.gov/crwhttp://response.restoration.noaa.gov/crwhttp://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=9804http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=9804http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=9804http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=9804http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=9804http://www.udel.edu/ehs/chemspillkit/chemspillguide.htmlhttp://www.udel.edu/ehs/chemspillkit/chemspillguide.htmlhttp://www-group.slac.stanford.edu/esh/eshmanual/references/toolsReqFlammable.pdfhttp://www-group.slac.stanford.edu/esh/eshmanual/references/toolsReqFlammable.pdfhttp://www-group.slac.stanford.edu/esh/eshmanual/references/toolsReqFlammable.pdfhttp://www-group.slac.stanford.edu/esh/eshmanual/references/toolsReqFlammable.pdfhttp://www.shimadzu.com/an/hplc/support/lib/lctalk/14/14lab.htmlhttp://www.shimadzu.com/an/hplc/support/lib/lctalk/14/14lab.htmlhttp://www.saskschools.ca/curr_content/chem30_05/6_redox/redox2_5.htmhttp://www.saskschools.ca/curr_content/chem30_05/6_redox/redox2_5.htmhttp://www.dtic.mil/whs/directives/corres/pdf/414526mp.pdfhttp://www.dtic.mil/whs/directives/corres/pdf/414526mp.pdfhttp://www.un.org/disarmament/convarms/Ammunition/IATG/docs/IATG01.50-UN_Explosive_Classification_System_and_Codes(V.1).pdfhttp://www.un.org/disarmament/convarms/Ammunition/IATG/docs/IATG01.50-UN_Explosive_Classification_System_and_Codes(V.1).pdfhttp://www.atf.gov/explosives/how-to/explosive-storage-requirements.htmlhttp://www.atf.gov/explosives/how-to/explosive-storage-requirements.htmlhttp://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=9755http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=9755http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=9755http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=9755http://chem.chem.rochester.edu/~nvd/http://chem.chem.rochester.edu/~nvd/http://orgchem.colorado.edu/Technique/Procedures/Procedures.htmlhttp://orgchem.colorado.edu/Technique/Procedures/Procedures.htmlhttp://orgchem.colorado.edu/Technique/Procedures/Procedures.htmlhttp://chem.chem.rochester.edu/~nvd/http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=9755http://www.atf.gov/explosives/how-to/explosive-storage-requirements.htmlhttp://www.un.org/disarmament/convarms/Ammunition/IATG/docs/IATG01.50-UN_Explosive_Classification_System_and_Codes(V.1).pdfhttp://www.dtic.mil/whs/directives/corres/pdf/414526mp.pdfhttp://www.saskschools.ca/curr_content/chem30_05/6_redox/redox2_5.htmhttp://www.shimadzu.com/an/hplc/support/lib/lctalk/14/14lab.htmlhttp://www-group.slac.stanford.edu/esh/eshmanual/references/toolsReqFlammable.pdfhttp://www.udel.edu/ehs/chemspillkit/chemspillguide.htmlhttp://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=9804http://response.restoration.noaa.gov/crwhttp://www.osha.gov/Publications/osha3151.pdfhttp://www.grainger.com/Grainger/static/emergency-shower-eye-wash-station-requirements-120.htmlhttp://www3.imperial.ac.uk/OCCHEALTH/guidanceandadvice/gloveinformationandguidance/gloveselectionguidancehttp://phmsa.dot.gov/staticfiles/PHMSA/DownloadableFiles/Files/Hazmat/ERG2012.pdf


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References 1. DOD Contractors Safety Manual for Ammunition and Explosives DoD 4145.26-

M. Aug 16, 2012. Web.

2. OSHA. 29 CFR 1910.151(c). Aug 16, 2012. Web.

3. Grainger. Emergency Shower and Eyewash Station Requirements. Aug 16, 2012.Web.

4. Aikens, David A. Principles and Techniques for an Integrated ChemistryLaboratory. Waveland. 1981. Print.

5. Harris, Daniel C. Quantitative Chemical Analysis. 8thed. W.H. Freeman. 2010.

Print. 6. University of Arizona. Risk Management Services.

http://risk.arizona.edu/images/chemcompchart_image.jpg. Aug 16, 2012. Web.

7. Shimadzu. Electromagnetic Type and Load Cell Type. 21 Aug, 2012. Web.

8. Shimadzu. Learning About Electronic Balances. 21 Aug, 2012. Web.

9. Radwag. Good Weighing Practice in Pharmaceutical Industry. 22 Aug, 2012. Web.

10. Scott, Ralph A., Jr. and Laurence J. Doemeny. Design Considerations for ToxicChemical and Explosives Facilities. American Chemical Society. 1987. Print.

11. Skoog, Douglas A., Holler and Nieman. Principles of Instrumental Analysis.Brooks/Cole. 1998. Print.

12. Chemical and Engineering News. Dow Chemical Teams Up with Universities onLaboratory Safety. http://cen.acs.org/articles/90/i44/Dow-Chemical-Teams-Universities-Laboratory.html. 19 Nov 2012. Web.

Basic Lab Practices

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