Refer to Table 4.4 for the selectivity coefficients for ions that interfere with the determination of creatinine by the experimental ISE described in Section 4.3. Assume that \(\mathrm{Na}^{+}, \mathrm{K}^{+}, \mathrm{NH}_{4}^{+}\), and \(\mathrm{Ca}^{2+}\) are present in a urine sample at \(0.16,0.06,0.035\), and \(0.005 \mathrm{M}\), respectively. What is the lowest concentration of creatinium ion that can be measured in the presence of these combined interferences, if one is willing to accept only a \(10 \%\) error in creatinine concentration?