Assigning Animals Randomly to different treatments

set.seed(3349)

conditions <- c("Control R1", 
                "Control R2", 
                "0.1 mg/L R1", 
                "0.1 mg/L R2", 
                "1 mg/L R1", 
                "1 mg/L R2", 
                "10 mg/L R1", 
                "10 mg/L R2", 
                "100 mg/L R1", 
                "100 mg/L R2",
                "100 mg/L R3",
                "1000 mg/L R1", 
                "1000 mg/L R2")
animal_id <- c("DM032024_C01", 
               "DM032024_C02", 
               "DM032024_C03", 
               "DM032024_C04*", 
               "DM032024_C05", 
               "DM032024_C06", 
               "DM032024_C07", 
               "DM032024_C08",
               "DM032024_C09",
               "DM032024_C10", 
               "DM032024_C11", 
               "DM032024_C12",
               "DM032024_C13")

treatment_assignments <- data.frame(
  Conditions = sample(conditions),
  animal_ID = sample(animal_id)
)
print(treatment_assignments)

     Conditions     animal_ID
1  1000 mg/L R2  DM032024_C13
2     1 mg/L R1  DM032024_C02
3   100 mg/L R1  DM032024_C01
4   0.1 mg/L R1  DM032024_C03
5    Control R1  DM032024_C05
6  1000 mg/L R1  DM032024_C11
7   100 mg/L R3  DM032024_C12
8     1 mg/L R2  DM032024_C09
9    Control R2  DM032024_C06
10  100 mg/L R2 DM032024_C04*
11   10 mg/L R2  DM032024_C10
12  0.1 mg/L R2  DM032024_C07
13   10 mg/L R1  DM032024_C08

#save assignments in csv for downstream use as metadata

setwd('..')
write.csv(treatment_assignments, file = "treatment_assignments_LC50_E3.csv")

Nickel Spiking Calculations

Nickel Chloride Dilutions

Review resources prior to handling nickel chloride:

Nickel chloride SDS.
Chemical resistance of gloves.

All handling of stock solution and treatments to be done in a chemical fume hood. Once spiked water has been distributed, add animals, parafilm jars, place in secondary container, and move to environmental chamber.

Required Volume of Artificial Seawater

Calculations for spiking artificial seawater. 225 mL of seawater required to mostly submerge glass slide in wide mouth 16 oz Kerr mason jar.

Considerations:

2 replicates and 3 for 100 treatment
225 mL per jar
6 conditions
Account for 10% loss of water during transferring
Additional 15 mL required for analytical chemistry

\[(2 * 225 * 6) + (15*6) + (0.1*(2*225*6)) + (0.1*(15*6)) = 3,069\]

Need 3,069 mL of artificial seawater total for exposure, particularly, 511.5 mL of artificial seawater per condition.

Calculations

Stock solution of NiCl₂ (10 g/L) made 04/08/24.

NiCl₂ (5g)
Suspended in MilliQ water (500 mL)

0.1 mg/L

\[ C_1*V_1 = C_2*V_2\] \[ 10 g/L * V_1 = 0.0001g/L*0.5115L\] \[V_1 = 0.000005115 L = 5.115 uL\] Spike 511.5 mL of aerated, artificial seawater (18 C) with 5.115 uL of stock NiCl₂ solution. Change in salinity negligible (+/- 1 PPT).

1 mg/L

\[ C_1*V_1 = C_2*V_2\] \[ 10 g/L * V_1 = 0.001g/L*0.5115L\] \[V_1 = 0.00005115 L = 51.15 uL\]

Spike 511.5 mL of aerated, artificial seawater (18 C) with 51.15 uL of stock NiCl₂ solution. Change in salinity negligible (+/- 1 PPT).

10 mg/L

\[ C_1*V_1 = C_2*V_2\] \[ 10 g/L * V_1 = 0.01g/L*0.5115L\] \[V_1 = 0.0005115 L = 511.5 uL\]

Spike 511.5 mL of aerated, artificial seawater (18 C) with 511.5 uL of stock NiCl₂ solution. Change in salinity negligible (+/- 1 PPT).

100 mg/L

\[ C_1*V_1 = C_2*V_2\] \[ 10 g/L * V_1 = 0.1g/L*0.759L\] \[V_1 = 0.00759 L = 7.59 mL\]

Spike 759 mL of aerated, artificial seawater (16 C) with 7.59 mL of stock NiCl₂ solution. Change in salinity negligible (+/- 1 PPT).

1000 mg/L

\[ C_1*V_1 = C_2*V_2\] \[ 10 g/L * V_1 = 1g/L*0.5115L\] \[V_1 = 0.0759 L = 51.15 mL\]

Spike 511.5 mL of aerated, artificial seawater (18 C) with 51.15 mL of stock NiCl₂ solution. Change in salinity negligible (+/- 1 PPT).