Fig. 6.

Internal standard introduction technique and dual trap design to enhance the performance of the miniature MS system. (a) Development of a simple, accurate and reproducible IS introduction and sample deposition using a capillary sampler (0.4 mm i.d., about 8 mm long). The capillary is filled with IS solution via capillary action. After drying in the air an IS coating is formed on the inner surface. The IS-loaded capillary was then used for blood sampling and deposition, during which the analyte is pre-mixed with the IS before MS analysis. (b) Analysis of imatinib in blood (10–4000 ng/mL) by PS-MS, where the capillary sampler was coated with imatinib-d8 as IS (Reprinted with permission from [78], American Chemical Society). (c) Dual linear ion trap MS equipped with DAPI (DAPI-QLIT-RIT) for MS analysis. Analysis of a analyte mixture containing 1 mg mL⁻¹ clenbuterol, 1 mg mL⁻¹ amitriptyline-d6, 200 ng mL⁻¹ amitraz, 500 ng mL⁻¹ cystine and 500 ng mL⁻¹ cocaine. Insets for MS/MS spectra of cystine, cocaine, clenbuterol, amitriptyline-d6, and amitraz in the mixture. (Reprinted with permission from [79], Royal Chemical Society).