interference.Rmd

# Interference # 

## Methods ##

* We are using disodium EDTA dihydrate
    * FW = 372.24 g/mol

* In a full EDTA tube there is 1.8 mg EDTA per millilitre of blood,
  this is equivalent to:
    * x mg/ml = 372.24 mg/mmol * 1/1000  L/ml
    * x = 0.37224 (mmol/L)/(mg/ml)
    * 1.8 mg/ml * 0.37224 (mmol/L)/(mg/ml) = 0.670032 mmol/L
    
* Make a 100 ml 0.5M EDTA stock:
    * 372.24 g/mol * 0.5 mol/L * 100 ml/1000 ml/L =  18.6 g
    * 18.6 g up to 100 ml of water
    * EDTA will go into solution at pH 8.0
    * add NaOH pellet to pH 8.0 
    
* Create a working solution of 100 mM EDTA
    * 200 ul 0.5 M EDTA + 800 ul water 
* Create a serial dilution:
  * 50 mmol/L = 500 ul (100mM EDTA) + 500 ul Water
  * 25 mmol/L = 500 ul (50mM EDTA) + 500 ul Water
  * 12.5 mmol/L = 500 ul (25mM EDTA) + 500 ul Water
  * 6.25 mmol/L = 500 ul (12.5mM EDTA) + 500 ul Water
  * 3.125 mmol/L = 500 ul (6.2mM EDTA) + 500 ul Water

* Add 75 ul of each concentration to the filter paper cards:

## EDTA Interference ##

```{r, fig.cap="\\label{fig:edta} EDTA Interferogram"}
edta <- read_xls(params$file, sheet = sheets$edta)
# edta %<>% na.omit()

ggplot(edta, aes(x = edta, y= measured, color = factor(cal))) +
    geom_point() +
    stat_summary(fun.y=mean, geom="line") +
    stat_summary(fun.data = mean_se, geom = "errorbar") +
    ylab("Measured Concentration")+
    xlab("EDTA (mM)")

``` 


\FloatBarrier