big talk written exam

When must you contact the agency?

• significant difference in weight

• Significant difference in agency case number

• Significant difference in evidence (submission sheet says marijuana and you receive white crystalline substance)

• Significant difference in suspect name

• Missing suspect

• Additional suspect

• Missing evidence

• Hidden evidence

What are some things we do to prevent sample swap and contamination?

• use barrier paper when sampling

• Gloves are changed when needed

• The bench top is cleaned between cases

• Only one case is open at a time

• Only one item is open at a time

• Balances are cleaned daily prior to use and when needed

• Consumables are used and kept in covered locations

• If reusable equipment is used a rinse is done

• Blanks are run before every sample

• We run two different tests on 2 different aliquots

• 1:1 checks

• Sequence checkers

• s/n requirement

• Swab for background contamination

• Evidence is kept in a sealed condition while not being worked

• Items are sealed after being worked

• Vial trays and test tube racks are cleaned biweekly

• Inside of drawers, lab coats, outer and inner surfaces of drawers and cabinets are cleaned monthly

• inner storage areas, fume hoods, and common spaces are cleaned biannually

• We clean sampling utensils before and after use

What is done in a full assessment? (Work on)

A full assessment occurs every four years. An outside team looks at all laboratory procedures and the management system across ISO 17025, AR 3125, ASCL-DOC-01, and DRG-DOC-01. If the accreditation requirements are looked at as a cake with ISO 17025 being the bottom layer and DRG-DOC-01 being the top layer, then a full assessment would be looking at the entire cake.

What is done in a surveillance assessment?

Surveillance assessments are smaller and are done in the off years between full assessments. They are done to ensure that the laboratory processes and management system are conforming to ISO 17025, AR 3125, ASCL-DOC01, and DRG-DOC-01. They look at one portion of the lab procedures and management system across all requirements. If the accreditation requirements are seen as a cake with the ISO 17025 being the bottom layer and DRG-DOC-01 being the top layer, then a surveillance assessment would be a slice of all of the layers of the cake.

Other than being an accreditation requirement, what is the purpose of internal audits?

Internal audits are done annually to ensure that we are following the laboratory procedures and management system policies outlined in ISO 17025, AR 3125, ASCL-DOC-01 and DRG-DOC-01. They are also done to ensure that personnel conform to the criteria set for them. They ensure that all personnel have the proper training, are competent, remain competent, and have the correct educational requirements.

What are the criteria for a positive GCRT match?

• passing blank (no peaks with a s/n > or = to 5 that are a retention type match for the analyte of interest that have a ms that is positive or indicative for the analyte of interest

• S/n > or = to 15

• Positive or indicative ms for the analyte of interest

• Appropriate peak shake (no splitting, tailing, or fronting)

• If the rt of the peak is above 3, then the rrt is less then or equal to 1%

• If the rt of the peak is less than or at 3, then the rrt is less than or equal to 2%

How is the GCMS library created?

• a reference material is run on the instrument

• The GCMS gives a sequential number for that reference material in the library

• The MS of the reference is added to the GCMS and named with the sequential number that the instrument gives, the name of the drug, and the MI

• The reference material is logged into the GCMS reference material library (ASCL GCMS Library Compounds) this includes: the sequential number that the GCMS gives, the name of the drug, the instrument it was run on, the molecular weight, the lot number of the reference material used

What is pharm ID?

Pharmaceutical identification is the comparison of the physical characteristics of a pharmaceutical, such as color, shape, and imprint, to a reference source

How is performance monitored?

• proficiency tests

• 100% technical and admin review process

• Case reexamination policy

• Testimony evaluation

• Internal audits

How is performance maintained?

• training

• Literature reviews

Explain SQ technically

Semi-quantitative analysis is the test we use to determine if a sample is marijuana. In this test a certified reference material is prepared to mimic a sample of marijuana that’s 1% D9-THC on a dry weight basis. A decision point is created in order to create a ratio of D9-THC to internal standard (we use tribenzylamine or TBA). This is run on the GCMS and used to create a 1 point calibration curve and the ratio of D9-THC to TBA is set to 1. A sample is prepared in a similar manner. The ratio of the response of D9-THC to TBA is plotted on the calibration curve. Is the response ratio of the sample is greater than or equal to 1, and all other testing agrees, then the sample is reported as marijuana. If the response ratio of the sample is less than 1, and all other testing agrees, the sample is reported as its constituents.

What are the limitations of SQ analysis?

Semi-quantitative analysis is not a quantitative test. It cannot give any accurate data about the percentage of D9-THC in a sample

Explain MU

The measurement of uncertainty in the variations in a measurement

Explain confidence level

• confidence level is the probability that the true value falls within a specific range

• Confidence level is the statistical measure of the percentage of measurements that can be expected to fall within a specified range

What is calibration and why is it important?

Calibration is the process of understanding how a balance behaves using certified reference weights. It is important because it establishes metrological traceability

Explain FTIR technically

Fourier transform infrared spectroscopy, or FTIR, is a structurally determining test. In this test a beam of IR light is shone through a beam splitter. One portion of the light splits off and hits a station mirror and is reflected back to the beam splitter. The other portion of the light splits off and hits a mobile mirror and is reflected back to the beam splitter. The beam is then recombined in the beam splitter and shone through an optically dense crystal. The light is reflected multiple times in the crystal creating an evanescent wave that extends slightly above the surface of the crystal. The sample is pressed against the crystal so that it can interact with the IR light. The IR light interacts with the sample and is absorbed and transmitted. This caused the bonds in the molecules in the sample to become excited, causing them to move and vibrate in specific ways. This information is referred to as an interferogram. The computer takes this information and performs a Fourier transform that converts the interferogram into a spectrum that can be read by an analyst. The spectrum shows the movements of the chemical bonds across the spectrum of wavelengths within the IR range. The spectrum is then compared to our traceable reference material library for positive identification.

When do you not need to take a weight?

• manufacture sealed packages

• Pharmaceuticals that have been pharmaceutically identified to contain no controlled substances

• Factory rolled cigarettes that are free from suspected tampering

• Liquid from paraphernalia or liquids that have been clearly marked to come from paraphernalia

• Residues

• Vapes

• Syringes

• Evidence in manufacturing or tampering cases (depending on the analysts experience)

What are some reasons for conflicting results?

• concentration differences

• Inappropriate test perfomed

• Inappropriate extraction performed

• Failure to do 1:1 checks

• Sample is not homogenous

• Contamination

When shall you perform a Pharm ID

• A pharmaceutical is being tested

• A pharmaceutical is suspected to contain a multi-schedule drug

• A pharmaceutical is suspected to contain a drug that completely breaks down on GCMS and substantiates the highest charge

• When all other analytically tested items yield NCSD

• To show that a non controlled pharmaceutical do not substantiate the highest potential charge

When should you perform a pharm ID?

• an analyst suspects that a tablet may be counterfeit but a 1:1 comparison is needed to make that conclusion

• items being tested may all yield non-controlled results

• Substance does not chromatograph well and does not substantiate the highest charge

• To show you don’t have 3-drug

• To differentiate isomers and salt/base forms

When shall you report a pharmaceutical as “identified as”

• the substance breaks down completely on GCMS and substantiates the highest charge

• A non-controlled pharmaceutical is the only thing in the case with no analytical testing

• There is nothing controlled in the case

When can you report a pharmaceutical as “identified as”

if it is a noncontrolled pharmaceutical

Explain GCMS to a jury

Gas chromatography mass spectroscopy, or GCMS, is an identification test. In this test a sample is run through the GC portion of the instrument which separates out the components of the sample. These components are then fragmented in the MS portion of the instrument. The pattern of fragmentation is used to create a spectrum that is compared to our traceable reference material library.

If there is no positive control for a color test, how are you confident that your reagents are still working?

• All reagents are verified before being put into use

• The resulting from the color test are consistent with our analytical results

Why is the chain of custody important?

It ensures that the integrity of the evidence is maintained while it is at the lab

What is the chain of custody?

The chain of custody is a record of the location of evidence from the time of it being received by the lab to the time of it leaving the lab. It gives information about the location of the evidence within the lab, the personnel that have interacted with it, and the secure transactions of the evidence