| Specimen requirement | Whole Blood | Urine |
| Adult patient: Special EDTA tube for trace elements Minimum blood volume: 2.6 mL |
Spot urine: Special acid wash bottle for trace elements Volume: 10 mL 24 Hr urine: U6 bottle
|
|
| Paediatric patient: Special EDTA tube for trace elements Minimum blood volume: 1.3 mL
|
||
| Authorisation code required | Yes | Yes |
| 24 Hr available service | No | No |
| Method | Inductively coupled plasma-mass spectrometry (ICP-MS) | |
| Reference interval |
Whole blood:
Normal < 77 nmol/L
(Source: Pathology 2009; 41(5): 467 - 72)
Action Limit > 175 nmol/L
(Source: Goldfrank’s Toxicologic Emergencies 6th Edition P.1319)
Urine:
< 5 nmol/mmol Cr < 50 nmol/day
(Source: SAS Trace Element Lab. Clin. and Analytical Handbook 2nd ed. 1992) |
|
| Clinical indication | Suspected
mercury poisoning Occupational exposure |
|
| Result interpretation |
Source of mercury in human can be originated from dietary (organic form), environmental (inorganic form), and occupational exposure (elemental and inorganic forms). A detailed history should be collected to delineate the source of exposure. All forms of mercury are toxic. For organic mercury, the main form is methyl mercury which can cross the placenta and blood brain barrier and hence the most toxic form. Abstinence from seafood is recommended for 4-6 weeks before the second blood mercury is collected for analysis. For exposure with elemental or inorganic form, urinary excretion of mercury can be used as diagnosis and monitoring of chelation therapy. |
|
| Measurement of uncertainty | See table. | |
| Frequency of measurement | Weekly | |