Acetonitrile acn

Hair collection kits were obtained from Kudzu Science (Strasbourg, France). All standards for preparing calibrators were purchased from Sigma-Aldrich (Saint-Quentin-Fallavier, France) and LGC (Molsheim, France). Acetonitrile (ACN) and methanol (MeOH) were purchased from Carlo Erba Reagents (Val-de-Reuil, France). All reagents were high-performance liquid chromatography (HPLC) grade. A blank hair matrix was obtained from a hairdresser (Strasbourg, France). Standard analyte mix stock solutions (1,000 µg mL⁻¹) were prepared in ACN or MeOH, as the situation required. A deuterated internal standard stock solution consisting of 4,4′-DDT D8 (5 µg mL⁻¹), Acetochlor D11 (5 µg mL⁻¹), Atrazine D5 (5 µg mL⁻¹), Isoproturon D6 (5 µg mL⁻¹), and Simazine D10 (1 µg mL⁻¹) was prepared in an ACN/MeOH mixture (50:50).

Vidaza^® powder glass vials for injection suspension were purchased from Celgene (Milan, Italy).
Sterile water for injection was purchased from Fresenius Kabi Italia (Verona, Italy. Product number B315343).
Reusable refrigerant gel packs were purchased from VWR International (Leuven, Belgium. Product number 216-0192).
Azacitidine reference material, pharmaceutical grade, was purchased from Merck Life Science S.r.l. (Milan, Italy. Product number PHR1911).
Ammonium acetate, methanol, and acetonitrile (ACN) were purchased from Carlo Erba Reagents S.r.l. (Cornaredo, Milan, Italy); ultrapure water (Milli-Q, 18.2 MΩ) was obtained from a Milli-Q^® IQ Element purification (Merck KGaA, Darmstadt, Germany).
All chemicals were of analytical grade and were used without further purification.
HPLC eluents (Milli-Q water, methanol, and ACN) were of high-grade purity.

All Fmoc-protected amino acids, Fmoc-Wang resins, DIC (N,N′-Diisopropylcarbodiimide), and Oxyma were purchased from Iris Biotech GmbH (Marktredwitz, Germany). The following amino acid side-chain-protecting groups were used: OtBu (Asp, Glu), tBu (Ser, Thr), Pbf (Arg), Trt (Gln, His), and Boc (Lys). Peptide-synthesis grade N,N-dimethylformamide (DMF) was purchased from Scharlau (Barcelona, Spain); acetonitrile (ACN) from Carlo Erba (Milan, Italy); dichloromethane (DCM), trifluoroacetic acid (TFA), piperidine were purchased from Sigma-Aldrich (Milan, Italy).