Why is hydrolysis sometimes used in opiate testing by GC-MS?

Why is hydrolysis sometimes used in opiate testing by GC-MS?

• A. To calibrate instrument's temperature.
• B. To convert glucuronide conjugates to free morphine, increasing detection sensitivity.
• C. To improve chromatographic run time.
• D. To change the color of the solution for easier reading.

Answer: (B)

Hydrolysis in opiate testing by GC-MS is used to convert glucuronide conjugates to free morphine, increasing detection sensitivity. In urine, morphine and its metabolites are often present as glucuronide conjugates (such as morphine-3-glucuronide and morphine-6-glucuronide). These conjugates can be less detectable by GC-MS because they are not the free, volatile form the method targets. By applying hydrolysis—usually enzymatic with beta-glucuronidase or acid hydrolysis—the glucuronide moiety is cleaved and free morphine is released. This increases the amount of detectable analyte, improving sensitivity and making the screening more reliable. The other options don’t address the analytic gain GC-MS relies on: calibrating instrument conditions, improving run time, or changing solution color don’t relate to the chemical form of the target analyte or its detectability.

Hydrolysis in opiate testing by GC-MS is used to convert glucuronide conjugates to free morphine, increasing detection sensitivity. In urine, morphine and its metabolites are often present as glucuronide conjugates (such as morphine-3-glucuronide and morphine-6-glucuronide). These conjugates can be less detectable by GC-MS because they are not the free, volatile form the method targets. By applying hydrolysis—usually enzymatic with beta-glucuronidase or acid hydrolysis—the glucuronide moiety is cleaved and free morphine is released. This increases the amount of detectable analyte, improving sensitivity and making the screening more reliable. The other options don’t address the analytic gain GC-MS relies on: calibrating instrument conditions, improving run time, or changing solution color don’t relate to the chemical form of the target analyte or its detectability.