To prevent your samples from becoming contaminated, use formic acid from small volume ampules rather from a large bottle. Impurities can accrue when taking aliquots of formic acid multiple times from the same bottle, and these impurities can impact positive ion analysis especially.
The six-peptide mixture (part number 4465940) is used for the calibration of mass spectrometers. The kit contains the following six peptides and their mono-isotopic masses: bradykinin (2-9 clip) (904.4681), angiotensin I (1296.6853), glu1-fibrinopeptide (1570.6774), ACTH (1-17 clip) (2093.0867), ACTH (18-39 clip) (2465.1989), and ACTH (7-38 clip) (3657.9294).
Protein preparation instructions can be found on the SCIEX website at https://sciex.com/Documents/tech%20notes/Protein-Preparation-Kit-Protocol.pdf or https://sciex.com/products/standards-and-reagents/automated-protein-digestion-solution.