Yes, I’ve always been using Spectrosil silica glass for the blank correction in quartz. According to the datasheet it has <10 ppb of each of the trace elements, except Cl (<1 ppm).
I’m running Smithsonian/Harvard Hot Springs Quartz as secondary standard, which based on LA-ICPMS done here has ~1 ppm Ti (at least in the chip that we've mounted) and I can reproduce that well using the Spectrosil blank correction. Recently I’ve also started using Shandong Quartz from Andreas Audetat (57 ppm Ti) as another secondary standard and can reproduce that well, too. I can do it the other way round (Hot Springs Qz for blank corr) with the same result.
Yes, there is some beam damage, but I’m not using quite as severe settings compared to some of the other posts.
The most severe settings are probably 15 kV, 200 nA, 5 um with 120 seconds on peak and 2x60 seconds on background. For those I can see no significant difference between doing normal peak/off-peak and alternating on/off peak, so any damage doesn't seem to significantly affect peak or background intensities.
We’re typically using 2 large PETs for Ti Ka, 2 TAPs for Al Ka and large LiF for Fe Ka. Si Ka either by EDS or just specified 100% SiO2.
That gives us 9 ppm detection limit for Ti and 4 ppm 1-sigma precision, which is good enough for us as the quartz we analyse usually has 10s to 100s ppm of Ti. We also do CL on the quartz (panchromatic or colour imaging or spectral CL) and then target zones distinct in CL in those grains with the EPMA point analyses. Where we can we put 2-3 points next to each other in the same zone to see if we can reproduce the composition and get better statistics.