Determination of L-hydroxyproline using hydrophilic interaction chromatography coupled to tandem mass spectrometry with lyophilized concentrated extraction in milk and dairy products.
In this study, a screening and confirmation method for the determination of l-hydroxyproline (Hyp) as a target compound in milk and dairy products using high-performance liquid chromatography with tandem mass spectrometry was developed. The samples were lyophilized after acidic hydrolysis, followed by cleanup with graphitized carbon black to remove pigments. Hyp was separated by a hydrophilic interaction chromatographic column and analyzed by high-performance liquid chromatography with tandem mass spectrometry working with multiple reaction monitoring mode using an electrospray ionization interface in a positive-ion mode. Average recoveries in spiked milk and dairy products ranged from 68.0 to 101.1% with relative standard deviations between 2.0 and 11.7% (n = 7). A reagent-matched standard calibration curve was used for quantification of Hyp, with linear correlation coefficient (R(2)) > 0.99 in the concentration range of 0.1-100 μg/mL. The LOQs were from 0.25 to 5 mg/kg, which were usually sufficient to verify the Hyp in samples. The confirmation concentration of Hyp ranged from 10 to 50 mg/kg.
Chinese Academy of Inspection and Quarantine, Beijing, China; College of Veterinary Medicine, China Agricultural University, Beijing, China.
Ai-ling
AL
Zhu
Tao
T
Peng
Dong-dong
DD
Chen
Ping
P
Wang
Guo-min
GM
Wang
Jin-hua
JH
Wang
Hai-yang
HY
Jiang
Chun-lin
CL
Fan
Ying
Y
Chen
D000818:Animals; D002417:Cattle; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D003611:Dairy Products / Q000032:analysis*; D057927:Hydrophobic and Hydrophilic Interactions; D006909:Hydroxyproline / Q000032:analysis*; D008892:Milk / Q000737:chemistry*; D053719:Tandem Mass Spectrometry / Q000379:methods*
D006909:Hydroxyproline
Hydrophilic interaction chromatography; Lyophilization; Milk and dairy products; l-Hydroxyproline; tandem mass spectrometry