ABSTRACT
Objective To propose an analysis method for determining 14 kinds of metal elements in collagen, including Mn, Cu, Zn, Al, Ti, Pb, Ba, Cd, Co, Cr, Ni, Fe, As and Hg. Method The conditions of collagen microwave digestion, inductively coupled plasma mass spectrometry (ICP-MS) working conditions and the modes used in the determination of various metal elements in ICP-MS were optimized. The content of 14 metal elements in 9 kinds of collagens with different specifications was determined by microwave digestion/ICP-MS, and the tagged recovery verification and method accuracy determination were conducted. Results The detection limit of the instrument was 0.1～5.0 μg/L. The detection limit of the proposed method was 0.00125～0.625 mg/kg. The relative standard deviation (n=11) was not more than 4.0％, and the recovery rate of the sample was 87.7％～107.4％. Under the same conditions, 14 metal elements in the pig liver standard were measured and the measured values were within the standard range. Conclusions The microwave digestion/ICP-MS method possesses the advantages of rapidness, simplicity, high sensitivity, good stability and high accuracy. It is worthy of reference and promotion.
ABSTRACT
Aninductivelycoupledplasmamassspectrometric(ICP-MS)methodbasedonquadrupole reaction/collision ( DRC) was developed for the determination of K,Na,Ca,Mg,Al,Cu,Zn,Pb,As and Mn in food. Samples were digested with HNO3 and H2 O2 followed by dilution with ultrapure water and then analyzed directly by ICP-MS. The signal sensitivity of high concentration element ( K, Na, Ca, Mg and Al ) was suppressed easily by adjusting the voltage parameters of DRC quadrupole ( Rpa) , and the food samples could be online diluted any multiples ( i. e. from one time to million times) according to the actual need. In order to eliminate mass spectral interferences of 40 Ar35 Cl+, the operational conditions of the DRC, working with CH4 as reaction gas, were optimized for 75 As. The limits of detection for the K, Na, Ca, Mg, Al varied from 0. 013-0. 027 mg/L, and Cu, Pb, Zn, As, Mnvaried from 0. 12-0. 61 μg/L. The accurate and reliable results were obtained for validation of the ICP-MS method with food reference material according to the national standard GBW10023 , GBW10015 , GBW10018 , GBW10017 , GBW10019 and GBW10024 . As the routine method in our laboratory, the satisfactory results indicate that it has great potential for the determination of low and high concentration level elements by one single analysis in various samples.