“…Of these, 50% (n = 7) had good precision (RSD < 3%), 17,19,21,25,28,29,31 14% (n = 2) an acceptable precision (RSD between 3% and 5%), 17,28 and 36% (n = 5) had low precision with an RSD >5% 19,20,23,27,32 . The accuracy of 5 studies (36%) was good, 16–18,21,22 another 4 (29%) had low accuracy, 20,22,26,27 and 5 other studies did not report accuracy 16,19,24,25,28 …”