Blog

Your unknown at 2.0 µL gives a lower calculated concentration than at 1.0 µL (ratio decreases). Most likely cause?

Calibration: I=mC+b. If m=[m], b=[b], and I=[i], compute C(ppm). (Report answer to 2 decimal places)

_______ such as sodium bicarbonate, magnesium hydroxide, calcium carbonate, or aluminum hydroxide, used to counteract or neutralize gastric acids and relieve the discomfort caused by gastric acidity. 

Preparing standards in DI water while samples are in 5% HNO₃ is acceptable because Ca²⁺ is the same ion in both.

Unknown Cmeas= [X] mg/L in run flask; DF=250. Compute Ca in digest (mg/L). (Report answer to the nearest whole number)

If the ISTD peak is integrated inconsistently (different baselines across runs), the ratio method can still be valid without correction.

If Cmeas=[C] mg/L came from I=?, m=[m], b=[b], verify I from I=mC+b. (Report to a whole number)

Which observations support the conclusion “Unknown 1 is cellulosic/cotton-type”?

What is the primary purpose of using an internal standard (Tridecane) in this GC experiment?

The internal standard in this experiment is Tridecane, which is added to both calibration standards and the __________ to correct for injection variations.