XRF options for soil / food


#1

Got a quote from China, they have an XRF which has similar specs to the Bruker, I’m sure it’s not quite as nice, but it’s quite a bit cheaper - quoted as $23,500. Bruker for the Tracer i5 was $38,000.

It looks very similar - columating optics, similar power and ppm resolution, same detector technology, option to manually calibrate a given matrix. I can’t quite tell the difference between their 3 models (3000, 5000, 7000 models), though it seems the 5000 is appropriate. I’ll follow up and ask which is best for the sample types we’re interested in.

Attached is the detailed quote. What do you all think?

https://drive.google.com/open?id=1Z6G_7w3oI_sRmVyR04HOdMAUapR576-c


#2

More details from LAN scientific. @david.n.forster @DanT hat’s your opinion… what list of elements is more important, what are the required detection limits and precision? I’d like to get Jill’s opinion also.

https://drive.google.com/open?id=0ByqRYMgnYFjBUVRLWnNTNE9NMmlJc2RFaEJNT19wT2lIVEJr

Also, I’m guessing we will select a subset of elements to actually calibrate also.


#3
U N/A N/A
Th N/A N/A
Pb 10 100
Hg 10 30
Au 20 50
Pt 30 A/S
W 60 160
Ba 85 120
Sb 34 56
Sn 35 45
Cd 15 15
Ag 10 20
Pd 10 20
Te N/A N/A
Mo N/A N/A Matters .01-2ppm
Zr 20 A/S
Sr 10 20
Rb 3 10
Se 6 10 Matters .01-1ppm X
As 5 10
Zn 6 15 Matters 1-100ppm X
Cu 6 30 Matters 1-30ppm X
Ni 10 30 Matters I don’t know
Co 10 25 Matters .05-5ppm X
Fe 10 40 Matters 10-400ppm
Mn 7 30 Matters 5-200ppm
Cr 10 40 Matters I don’t know
V 15 50 Matters Unknown?
Ti 10 50
Sc 15 40
Ca 30 85 Matters 500-5000ppm
K 50 100 Matters 50-500ppm
S 280 500 Matters 5-200ppm X
P 350 450 Matters 20-2000ppm X
Si N/A N/A Matters 10-50ppm X
Al 700 1300 Matters 30-1500ppm X
Mg 4500 9400 Matters 50-500ppm X

#4

Source spreadsheet for above:
https://docs.google.com/spreadsheets/d/178XhedMfTh2F4wlNGHf6vUGgVTW8GV0KGaFBqaavYpE/edit?usp=sharing


#5

High Performance TXRF Spectrometer for Ultra-Trace Element Analysis


ppb xrf


#6

I updated the spreadsheet based on information in the USDA database on carrots, spinach, tomatoes, and two types of wheat:

https://ndb.nal.usda.gov/ndb/search/list

This database is quite broad and has a lot of samples for the major crops, so it gives us a nice range. It’s unclear if they samples from a wide variety of organic/non-organic/etc etc or if it’s just from grocery stores, so we may have a broader range, we’ll just have to see. But in general, the range was ±50% of the average value.

So this will help direct the discussion, and also we’ll need to buy purified forms of each of these elements to do a standards.