11-nor-9-Carboxy-THC, also known as THCA or carboxy-THC, is the main secondary metabolite of THC (the active component of marijuana) formed in the human body [1]. THCA is excreted in urine in the form of glucuronide conjugates. THCA is not psychoactive but has a long half-life of up to several days or even weeks in very heavy users, thus determination of THCA in urine plays an important role in confirmation of marijuana consumption. The Substance Abuse and Mental Health Services Administration (SAMHSA) has set the THCA cutoff concentration of confirmatory testing at 15 ng/mL. Typical sample preparation methods for THCA in urine include liquid-liquid extraction (LLE) and solid phase extraction (SPE). This application utilizes a novel sample preparation technique, QuEChERS to effectively quantitate THCA levels in human urine.
In this seventh part of " Conversations with Michael Dong," a series on fundamentals of HPLC in pharmaceutical analysis, LCGC International’s "Perspectives in HPLC" column editor explains why 2.1-mm i.d. columns are less preferred for pharmaceutical quality control.
Ultrahigh-performance liquid chromatography–quadrupole time-of-flight mass spectrometry (UHPLC–QTOF-MS) shows how soaking and cooking break down soybean fats.
Nicolai Zederkopff explores chromatography’s role to help implement the maximum tolerable level (MTL) framework for food adulteration to translate analytical results into compliance decisions.
Franz Berthiller (BOKU University, Austria) discusses a multilaboratory study that used retention index markers to align mycotoxin liquid chromatography–mass spectrometry (LC–MS) data.
A QuEChERS/ultrahigh-performance liquid chromatography and high-resolution mass spectrometry (UHPLC-HRMS) method tracks 23 plant toxins in cereals and spices. Michele Suman discusses the method with LCGC International.
