Order Code ASUCR Arsenic/Creatinine, Ratio, with Reflex, Random, Urine
Specimen Required
Patient Preparation:
1. For the 48-hour period prior to start of collection, patient should not eat seafood.
2. High concentrations of gadolinium and iodine are known to interfere with most metal tests. If either gadolinium- or iodine-containing contrast media has been administered, a specimen should not be collected for 96 hours.
Supplies: Urine Tubes, 10 mL (T068)
Collection Container/Tube: Clean, plastic urine container with no metal cap or glued insert
Submission Container/Tube: Plastic, 10-mL urine tube or clean, plastic aliquot container with no metal cap or glued insert
Specimen Volume: 6 mL
Collection Instructions:
1. Collect urine a random urine specimen.
2. See Metals Analysis Specimen Collection and Transport for complete instructions.
Useful For
Preferred screening test for detection of arsenic exposure using random urine specimens
Profile Information
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| ASCU | Arsenic/Creatinine Ratio, U | No | Yes |
| CRETR | Creatinine, Random, U | No | Yes |
Reflex Tests
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| SPAS | Arsenic Speciation, Random, U | Yes | No |
Testing Algorithm
If total arsenic concentration is 10 mcg/L or greater, then speciation will be performed at an additional charge.
Special Instructions
Method Name
ASCU: Triple-Quadrupole Inductively Coupled Plasma Mass Spectrometry (ICP-MS/MS)
CRETR: Enzymatic Colorimetric Assay
Reporting Name
Arsenic/Creat w/Reflex, Random,USpecimen Type
UrineSpecimen Minimum Volume
3 mL
Specimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Urine | Refrigerated (preferred) | 28 days |
| Frozen | 28 days | |
| Ambient | 72 hours |
Reject Due To
All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.Reference Values
ARSENIC/CREATININE:
0-17 years: Not established
≥18 years: <24 mcg/g creatinine
CREATININE:
≥18 years: 16-326 mg/dL
Reference values have not been established for patients who are younger than 18 years of age.
Method Description
The metal of interest is analyzed by triple-quadrupole inductively coupled plasma mass spectrometry. (Unpublished Mayo method)
Creatinine:
The enzymatic method is based on the determination of sarcosine from creatinine with the aid of creatininase, creatinase, and sarcosine oxidase. The liberated hydrogen peroxide is measured via a modified Trinder reaction using a colorimetric indicator. Optimization of the buffer system and the colorimetric indicator enables the creatinine concentration to be quantified both precisely and specifically. (Package insert: Creatinine plus ver 2. Roche Diagnostics; V15.0, 03/2019)
Performing Laboratory
Mayo Clinic Laboratories in Rochester
CPT Code Information
82175
82570
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| ASUCR | Arsenic/Creat w/Reflex, Random,U | 13463-5 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| CRETR | Creatinine, Random, U | 2161-8 |
| 608900 | Arsenic/Creatinine Ratio, U | 13463-5 |
| 608901 | Total Arsenic Concentration | 5586-3 |
Day(s) Performed
Monday through Friday