Analyzing Unknown Drug Samples

<ol> <li>Sample receipt and documentation, 2. Preliminary testing, 3. Sample preparation, 4. Instrumental analysis, 5. Data interpretation and analysis, 6. Final confirmatory analysis.</li> </ol> Signup and view all the answers

<p>Proper documentation of sample receipt ensures traceability and integrity of the sample, which is crucial in maintaining chain of custody and preserving the evidentiary value of the sample.</p> Signup and view all the answers

<p>The purpose of the final confirmatory analysis is to conclusively identify and quantify the presence of specific drugs or compounds in the sample, providing legally defensible results.</p> Signup and view all the answers

<p>Both liquid-liquid extraction and solid phase extraction are sample preparation techniques used in analytical chemistry. They both involve the separation of compounds from a mixture based on their physical and chemical properties. Both techniques are commonly used to isolate and concentrate analytes from complex matrices before analysis.</p> Signup and view all the answers

<p>The main difference between liquid-liquid extraction and solid phase extraction is the type of phase used for extraction. In liquid-liquid extraction, two immiscible liquid phases are used, typically an organic solvent and an aqueous phase. The target analytes partition between these two phases based on their solubility. In solid phase extraction, a solid sorbent material is used to selectively retain the analytes while the unwanted components are washed away. The retained analytes are then eluted for further analysis.</p> Signup and view all the answers

<p>Liquid-liquid extraction functions by taking advantage of the differential solubility of analytes in two immiscible liquid phases. The sample is mixed with an organic solvent and an aqueous phase. The target analytes partition between these two phases based on their solubility. After separation, the organic phase containing the analytes of interest is collected and further processed for analysis.</p> Signup and view all the answers

<p>Solid phase extraction functions by selectively retaining the target analytes on a solid sorbent material while the unwanted components are washed away. The sample is loaded onto a solid phase extraction cartridge or disk containing the sorbent material. The analytes of interest adsorb onto the sorbent while the interfering compounds pass through. After washing away the unwanted components, the retained analytes are eluted from the sorbent for subsequent analysis.</p> Signup and view all the answers

<p>Both methods rely on the principle of partitioning</p> Signup and view all the answers

<p>Liquid-liquid extraction uses a solid support, while solid phase extraction uses a liquid support</p> Signup and view all the answers

<p>By partitioning analytes between two immiscible liquid phases</p> Signup and view all the answers

<p>The steps involved in the typical analysis protocol for an unknown drug sample include preliminary visual examination, weighing of evidence, selection of representative samples, screening tests, confirmatory tests, and quantitation if necessary.</p> Signup and view all the answers

<p>The steps involved in marijuana analysis include observation under a stereomicroscope for cystolith hairs, Duquenois-Levine color test, thin layer chromatography, and possibly a confirmatory test for THC or other cannabinoids.</p> Signup and view all the answers

<p>Liquids and residues in syringes can be subjected to color tests, thin layer chromatography, UV spectroscopy as screening procedures, followed by GC-MS confirmation.</p> Signup and view all the answers