This laboratory has Emission Spectrograph and Micro photometer have advantages include requiring lower sample and 15 elemental analysis. Main activity of this center is qualitative analysis of gold in geochemical and mineralized samples.
  This spectrograph in laboratory center of Karaj consists of an Arc exciting source with alternate electrical current in which a pair of graphic electrodes with distance less than a few millimeters is considered as Arc source. In this technique, powder sample is charged on the hole of an electrode and the next electrode performs as a reference electrode. 

Detection Limit (ppm)	Element
2.0	Cu
2.0	Pb
30.0	Zn
0.03	Ag
1.0	Sn
0.5	Mo
10.0	B
2.0	Ni
20.0	Cr
2.0	Co
1000	Ti
100	Mn
0.5	Be
100	Ba
0.001	Au

ES preparation lab is one of preparation laboratories in Applied Research Center of Geological Survey which are used for preparation of 3 elements of Ag, B, Sn.
This laboratory has 1 expert and 1technician which samples are prepared under direct supervision of them. For preparation of elements such as Au, B, Sn, first samples are weighted and then, are pulverized on agate pestles. Finally, samples are introduced into emission spectrograph unit (ES).        
ES Preparation Steps:
- Weighting 0.03gr of sample
- Homogenizing with 0.03gr buffer
- Loading on graphic electrode
- Creating electric arc for capturing emission spectra
- Read out spectra lines using micro photometer
ES Laboratory Instruments:
1. Becher
2. Agate pestle
3. Graphic Electrode
4. Alchohol
5. Chemicals used for preparation of internal standards 

In this laboratory which includes 1 expert and 1 technician, samples are prepared under direct supervision. For example, for preparation of gold, first samples are weighted and then are introduced into preparation unit for addition of aqua regia and refining. Samples, after preparation, are introduced into ES Lab of Applied Research Center of Geological Survey of Iran.  
Au Preparation Steps:
- Weighting of 10gr sample
- Heating on furnace
- Digestion with aqua regia (HNO¬¬¬3,HCl 3:1)
- Pass of solution on column of active carbon for absorption of gold
- Burning phase of active carbon
- Loading ash remained from previous step on a graphic electrode for recording emission spectra 
Au Preparation Laboratory Instruments:
1. Crucible
2. Becher
3. Heater
4. Hood
5. Furnace
6. Refinery shelf
7. Filtration tubes
8. Filter paper