Nowdays,I find that in the CUAAC reaction,the Cu2+ TBTA TCEP system is more better than the Cu2+ THPTA Vc,because the pellete after precipitated of TBTA TCEP has much strong color than the THPTA Vc system.however,I search many articles,they say the THPTA Vc system is more effective than TBTA TCEP,so ,what's the truth?or these two system are suitable for different suitation?