{'fraction_non_alphanumeric': 0.043119266055045874, 'fraction_numerical': 0.022018348623853212, 'mean_word_length': 5.129213483146067, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Theophylline, dyphylline, caffeine, acetaminophen, salicylate, acetylsalicylate, procainamide, and N-acetylprocainamide determined in serum with a single liquid-chromatographic assay.

We describe a single set of liquid-chromatographic conditions for assay of theophylline, dyphylline, caffeine, acetaminophen, salicylate, acetylsalicylate, procainamide, and N-acetylprocainamide in serum. The chromatographic system includes a Waters Associates mu-Bondapak C18 column and acetonitrile in 0.1 mol/L potassium phosphate buffer, pH 4.0 (9.75/90.25 by vol), as the mobile phase. Only 50 microL of serum is required, and drug concentrations as low as 0.5 mg/L can be detected. Absolute and relative analytical recoveries range from 95 to 101%. Day-to-day variation of the method is less than 6% for each drug. Linearity extends to 1 g/L for all drugs. Recycling of the mobile phase under pressure eliminates the need to prepare and de-gas solvents. The use of the single stationary and mobile phase provides a practical and economical approach to routine and urgent therapeutic drug monitoring.