Date: 8-MAY-2014 Last Updated: 27-JANUARY-2026
Two Types of Retentions are Described in this Application NoteThe four analytes were successfully retained and baseline‑resolved under both chromatographic conditions, as shown in Figures A and B. A change in retention order was observed between the two gradients, reflecting the different selectivity characteristics of ANP and RP modes. Additionally, overall peak intensities were approximately three times greater with Gradient “A” (ANP mode) compared to Gradient “B” (RP mode), indicating a substantially enhanced response under ANP conditions.
Peaks:
1. Temazepam
301.0739 m/z [M+H]+
2. Diazepam
285.0790 [M+H]+
3. Nordiazepam
271.0633 [M+H]+
4. Midazolam
326.0855 [M+H]+
Column: Cogent Diol™, 4.4µm, 100Å
Catalog No.: 40060-05P-2
Dimensions: 2.1 x 50mm
Mobile Phase:
-- A: DI Water with 0 .1% Formic Acid (v/v)
-- B: Acetonitrile with 0.1% Formic Acid (v/v)
Gradient:
| Figure A | Figure B | ||
|---|---|---|---|
| Time (minutes) | %B | Time (minutes) | %B |
| 0 | 85 | 0 | 10 |
| 6 | 70 | 6 | 10 |
| 7 | 20 | 7 | 50 |
| 9 | 20 | 9 | 50 |
| 10 | 85 | 10 | 10 |
Injection vol.: 1µL
Flow rate: 0.4ml / minute
Detection: ESI – POS – Perkin Elmer AxION 2 TOF Mass Spectrometer
Flow rate: 0.4ml / minute
Sample Preparation: Extraction Method: Spiked urine sample was loaded into SPE cartridge I (Clean Screen Xcel™ purchased from UCT Bristol, PA, USA) and eluted with 0.78mL of Acetonitrile, 200µL of 2-Propanol, 20µL of Ammonia. After the elution, the Sample was dried under Nitrogen gas and dissolved in 100µL of 50:50 Methanol / DI Water / 0.1% Formic Acid. Before injection, the 10ppm spiked Sample was filtered through a 0.45µm Nylon Syringe Filter (MICROSOLV Tech Corp).
Notes: Benzodiazepines are prescribed for conditions such as anxiety disorders, insomnia, seizures, and alcohol withdrawal. However, they also have potential for abuse as recreational drugs.
Attachments No 306 1,4-Benzodiazepines in Urine Analyzed using RP and ANP pdf 0.3 Mb Download File